Root Crops in November

Root Crops to Plant in Central Virginia in November

We have reached the slow-growing time of year. We have passed our last chance to sow root crops outdoors. Nothing changes fast. Reread Root Crops in October for more ideas, if you are in a warmer climate zone than us. We are in Winter-hardiness zone 7, which has overall minimum average of temperatures of 0° to 10°F (-18°C to -12°C). We are in subzone Zone 7a, with a minimum average temperature of 0° to 5° F (-18°C to -15°C).

In late November, we sow our fourth radishes in our hoophouse. See Root Crops in September for more about our succession of hoophouse radish sowing dates. We sow Easter Egg, and White Icicle. It is too late for us to sow Cherry Belle or Sparkler types – they get too fibrous. This sowing will feed us for the month of February. Unlike the late October sowing which lasts for 8 weeks, this sowing will only be good for 4 weeks.

See Root Crops in September for information on figuring sowing dates for winter hoophouse succession crops (radishes are the example)

Late September in our hoophouse: radishes, scallions and new transplants in the beds on either side. Photo Wren Vile

In early November (around 11/9), we often sow our second of three plantings of hoophouse turnips. We sow Hakurei, Early White Egg, Oasis, and Red Round. These will be harvested 2/25-3/10 (with thinnings for greens from 1/11).

Sometimes we make our second sowing in late October, if we have space available then and want bigger turnips. We may make a third turnip sowing in very early December if space opens up then. The third sowing is only worthwhile if thinned promptly and eaten small, as the plants will start bolting in early March.

See Root Crops in October, for details of thinning and harvesting.

Root Crops to Harvest in Central Virginia in November

Large Smooth Prague celeriac.
Photo Southern Exposure Seed Exchange

Florence bulb fennel. Photo
Southern Exposure Seed Exchange

If you are unsure how soon temperatures will drop in your area, see Weatherspark

Enter your city, airport or zipcode and you’ll get access to helpful graphics on seasonal temperatures, cloud coverage, rainfall, snow, sunshine, humidity, wind, water temperature at nearby large bodies of water. Also tourism, which I had not previously thought of as a type of weather! After that comes an assessment of growing conditions (considered only as days without frost) and growing degree-days, solar energy, and more.

In Louisa County, where we are, the average daily low temperature in November makes a precipitous but erratic slide from 45°F (7°C) to 36°F (2°C), with a small chance of going as low as 24°F (-4°C) by the end of November. Most of our root crops other than sweet potatoes and potatoes can wait to be harvested until late November, but we would rather proceed with harvesting and storing, as the daylight gets shorter and the chance of cold, wet working conditions get higher.

Green kohlrabi.
Photo Small Farm Central

We continue clearing root crops outdoors and storing them (in this order):

· 25°F/-4°C, bulb fennel
· 20°F/-7°C, turnips, winter radish, celeriac
· 15°F/-9°C, kohlrabi, beets (15-20°F/-9 to -7°C, depending on variety)
· 12°F/-11°C, carrots, Cylindra beets
· 10°F/-12°C, parsnips, probably OK to 0°F (-18°C)
· Horseradish is not killable by cold temperatures, as far as I can tell. But if the ground is frozen, you can’t dig it up.

Wash and store roots in perforated plastic bags under refrigeration, or in a root cellar or other cold storage place.

Our 9/6 sowing of hoophouse radishes will have finished and our second sowing will mature and brighten our meals from 11/6 to 12/25 approximately. Our first sowing of hoophouse turnips (10/15) will produce edible little roots as thinnings later in the month.

See Washing, sorting and storing root crops in Root Crops in September.

See my list of Winter-Kill Temperatures of Cold-Hardy Vegetables 2020 for a more complete picture of “Harvesting in Time”

Other Root Crop Tasks in Central Virginia in November: Long term storage of sweet potatoes and white potatoes

Sweet potatoes

After curing, store boxes of sweet potatoes at 55-60°F (13-15.5°C), 50-60% humidity. Curing is complete when the skin is undamaged after rubbing two together. If the heating in your curing space is variable, be sure to check several boxes of sweet potatoes closer to and further from the heater. We once had a sad thing happen after a new heater had been installed. We were checking the most accessible boxes only, not the ones at the back near the heater. We got wrinkly sweet potatoes. If your crop is not curing as fast as you hoped, check the temperature, and do what you can with fans to move the air around without blasting directly on any particular box. Also check the humidity and adapt as needed. We found that splashing water directly on the concrete floor of our basement was the most successful method.

Restack the boxes (in a rodent-proof storage cage, if you are using an outbuilding).

Peruvian (“white”) potatoes

Potatoes stored in crates in our root cellar.
Photo Nina Gentle

Sort white potatoes in storage 2 weeks after harvest. See Root Crops in August

Root Cellar: Cool to 50°F (10°C) after one month, then 40°F (4.5°C), airing once a week or less if cooling not needed. See Special Topic for July

Special Root Crop Topic for November in Central Virginia Vegetable storage without electricity.

· Meeting the storage requirements of various crops helps maximize their season of availability
· Some vegetables need to cure before storage and the curing conditions are different from those needed for storage. Curing allows skins to harden and some of the starches to convert to sugars.
· Many crops may be stored without electricity, perhaps in buildings that serve other uses at the height of the growing season.

· Washington State University Extension’s Storing Vegetables and Fruits at Home, is a good introduction to alternatives to refrigerated storage, using pits, clamps and root cellars. Drawings below are from WSU Storing Vegetables and Fruits at Home
· Also old versions of the USDA Agriculture Handbook 66.

Home vegetable storage options, from WSU

Four Sets of Storage Conditions

By providing storage spaces with 4 types of conditions, 25 crops can be stored.

· In my chart in Sustainable Market Farming, the Summary column indicates the general conditions needed for each crop, and allocates each crop to one of 4 groups:
· A= Cold and Moist: 32°F–40°F (0°C–5°C), 80%–95% humidity — refrigerator or winter root cellar conditions. Most roots, greens, leeks
· B= Cool and Fairly Moist: 40°F–50°F (5°C–10°C), 85%–90% humidity — root cellar. Potatoes
· C= Cool and Dry: 32°F–50°F (0°C–10°C), 60%–70% humidity — cooler basements and barns. Garlic and onions
· D= Warm and Dry to Fairly Moist: 50°F–60°F (10°C–15°C), 60%–70% humidity — basements. Sweet potatoes and winter squash.

Our winter squash storage cage. Photo Twin Oaks Community

Winter squash and pumpkins – storage

We built a rodent-proof cage with wood shelves. You could use shallow crates to avoid handling each individual squash.

In-ground protected vegetable storage. WSU

In-ground storage

Depending on the severity of your winter, some cold-hardy root crops (turnips, rutabagas, beets, carrots, parsnips, Jerusalem artichokes and horseradish) and also leeks can be left in place in the ground, with about 12” (30 cm) of insulation (straw, dry leaves, chopped corn stalks, or wood shavings) added after the soil cools to “refrigerator temperatures.”

Hooped rowcovers or polyethylene low tunnels can keep the worst of the weather off. There could be some losses to rodents, so experiment on a small scale the first winter to see what works for you. We have too many voles to do this with carrots or turnips.

Besides being used as a method for storage of hardy crops deep into winter, this can be a useful method of season extension into early winter for less hardy crops such as beets, celery and cabbage, which would not survive all winter this way. Access to crops stored in the ground is limited in colder regions — plan to remove them all before the soil becomes frozen, or else wait for a thaw.

Storage clamps (mounds)

Cabbage, kohlrabi, turnips, rutabagas, carrots, parsnips, horseradish, Jerusalem artichokes, salsify and winter radishes (and any root vegetables that can survive cold temperatures) can be stored with no electricity, by making temporary insulated outdoor storage mounds (clamps).

Mark a circular or oval pad of soil, lay down straw, pile the roots up, cover them with straw and then with soil, digging a drainage ditch round the pile. For ventilation, leave a tuft of straw poking out. Slap the damp soil in place to protect the straw and shed rainwater.

For the backyarder, various roots can be mixed, or sections of the clamp can be for different crops. Those growing on a large scale would probably want a separate clamp for each crop. It is possible to open one end of a clamp or pit, remove some vegetables, then reseal it.

There is a balance to be found between the thermal buffering of one large clamp and the reduced risk of rot that numerous smaller clamps provide.

Pits and trenches

Dig a deep, wide pit (3+ feet deep) in a dry area where water will not stand, lining it with heavy plastic and straw. Alternate layers of vegetables with layers of straw, finishing with straw. Put a loose sheet of plastic on top, (not sealed down). Cover with more soil.

To deter rodents, bury large bins such as (clean) metal trashcans, layer the vegetables inside with straw, and cover the lid with a mound of more insulation and soil.

Or bury insulated boxes in the ground inside a dirt-floored shed or breezeway. A new life for discarded chest freezers! Insulated boxes stored in unheated areas need 6-8” (15–20 cm) of insulation on the bottom, sides and top.

Root Cellars for crops needing cool, damp conditions

· Potatoes do best in a dark cellar, at 40° – 50°F (5° -10°C). With a good in-ground root cellar, potatoes store for 5-8 months. Ventilate as needed, to maintain the cellar in the ideal range.
· Below 40°F (5°C) the starches convert to sugars, giving potatoes an unpleasant flavor and causing them to blacken if fried.
· Root cellars can be used for apples, cabbage, or root vegetables, but be careful what you mix.
· Some people pack the unwashed roots in boxes of sand, wood ash, sawdust or wood chips. Perforated plastic bags or crates are easier.
· Pepper plants can be hung upside down in a cellar to ripen, or store. Cabbage can also be hung upside down.
· Cabbage, celery, leeks can be replanted side by side in boxes or tubs of soil.

Our root cellar for potatoes. Photo McCune Porter

Ethylene

Ethylene is generally associated with ripening, sprouting and rotting. Some crops produce ethylene gas while in storage — apples, cantaloupes and ripening tomatoes all produce higher than average amounts. Environmental stresses such as chilling, wounding and pathogen attack can all induce ethylene formation in damaged crops. Some crops, including most cut greens, are not very sensitive to ethylene and so can be stored in the same space as ethylene-producing crops. Other vegetables, however, are very sensitive to the gas and will deteriorate in a high-ethylene environment. Potatoes will sprout, ripe fruits will go over the top, carrots lose their sweetness and become bitter.

Storing potatoes

Potato crates in our root cellar.
Photo Nina Gentle

Storing potatoes

This is part of a monthly series on growing potatoes, a dietary staple.

PART ONE: Planting potatoes (April)

PART TWO: Growing potatoes (May)

PART THREE: Potato pests and diseases (June)

PART FOUR: Harvesting potatoes (July)

PART FIVE: Storing potatoes (August)

PART SIX: Planning to grow potatoes again (September)

I have a whole chapter about potatoes in my book, Sustainable Market Farming, and another on root cellars (including construction), where much of this information can be found.

This year’s new Victory Gardeners now need to learn how to store your harvest, so it can supply your household for as long a s possible. As more commercial growers aim to produce local food sustainably year-round, the storage of vegetables for sale over the winter becomes important. Understanding the needs of different crops can help reduce your electricity bill and carbon footprint, and maximize the amount of produce you can store for later sale. Only critical crops need refrigeration. Potatoes should not be refrigerated. Many others may be stored without electricity, perhaps in buildings that serve other uses at the height of the growing season.

Our in-ground root cellar. Photo McCune Porter

A 1978 publication from Washington State University Extension, Storing Vegetables and Fruits at Home, is a good introduction to alternatives to refrigerated storage, using pits, clamps and root cellars. There is also good information in USDA Agriculture Handbook 66. 2016 revision. Many growers are still using the 1986 version, but it’s worth checking newer recommendations and additional advice. UMass Extension has a good site on post-harvest and storage resources. Nancy and Mike Bubel’s book Root Cellaring has a wealth of information, including how to build a root cellar.

Don’t expect a one-shed-fits-all solution to crop storage. I identify five different sets of storage requirements, for different storage crops. This one is specific to potatoes, which don’t want colder conditions: Cool and moist: 40°F–50°F (5°C–10°C), 85%–90% humidity. With a good in-ground root cellar, potatoes can be stored for 5-8 months, but other options can also work. A max-min thermometer will help you keep the storage space in the right range.

We removed all the soil to renovate our root cellar roof. Photo McCune Porter

Reasonable expectations

Only store sound potatoes. Garbage in, garbage out. Damaged and poor quality vegetables will not store well. Always handle all crops for long-term storage gently, to avoid bruising. For long-term storage, make sure crops are fully mature but not over-mature when you harvest. Potatoes need firm skins that don’t rub off when you rub with a thumb. This is different from some crops, such as beets and sweet potatoes, that don’t have a “ripe” stage, but are ready when they reach the size you like. Very small vegetables don’t store well. Expect that a small percentage of your crops will go bad in storage — it’s not a sign of failure, just a reminder that life has limitations.

Cure, then store

Potatoes are one of those vegetables that need to cure before storage in conditions that are different from those needed for storage. Curing allows skins to harden and some of the starches to convert to sugars. See the post on Harvesting Potatoes in July. Potatoes need curing in moist air (90% humidity) for one to two weeks at 60°F–75°F (15°C–24°C). You may be surprised at how warm this is. Wounds in the skin will not heal below 50°F (10°C).

We sort our potatoes after two weeks of curing and find this usually reduces the chance of rot so that we don’t need to sort again. With potatoes, the rate of deterioration drops right down after a few weeks. Remember to keep white potatoes in the dark while curing as well as during storage.

When filling stackable crates, leave space for the crates to lock into each other.
Photo Nina Gentle

Preparation for storage

Plan your storage sites, buy a thermometer for each site, and gather suitable containers. Clean and prepare your storage space before going out to do a big harvest. Wood crates are good for nostalgia and agritourism, but plastic is kinder on aging backs and less likely to harbor diseases. Containers should rest on shelves, pallets or blocks of some kind, and not be set on bare concrete floors. This helps improve ventilation and reduce condensation.

For traditional storage without refrigeration, potatoes (and most other root crops) store best unwashed (less wrinkling), though this can make them harder to clean later. If you might not be able to keep temperatures low enough, choose stackable crates rather than closed bags. When you have choice in the matter, try to harvest potatoes from relatively dry soil, so they are less likely to grow mold. The packing of your containers should allow for airflow, but you don’t want the produce to shrivel up, so be observant. Sometimes night ventilation offers cooler, drier air than you can get in the daytime. Keeping root cellar temperatures within a narrow range takes human intervention, or sophisticated thermostats and vents. If needed, electric fans can be used to force air through a building.

Ethylene

Ethylene is an odorless, colorless gas, generally associated with ripening, sprouting and rotting. Chilling, wounding and pathogen attack can all induce ethylene formation in damaged crops.

Some crops, including most cut greens, are not very sensitive to ethylene and so can be stored in the same space as ethylene-producing crops. Potatoes are very sensitive to ethylene and will sprout in a high-ethylene environment.

Some crops, such as ripening fruits, produce ethylene gas while in storage. Don’t be tempted to set that bargain box of very ripe bananas you bought on the way home near anything you don’t want to sprout or ripen further. Propane heaters and combustion engines produce ethylene. Be careful if using your garage to store potatoes.

Our 10’ x 11.5’ (3 x 3.5 m) cellar will hold 10,800 pounds (4900 kg), or around 5 tons (tonnes)of potatoes. Photo Pam Dawling

Basement storage rooms and root cellars

Traditional root cellars are made by excavating a large hole near the house, lining it with block or stone-work walls, casting a well-supported and well-insulated concrete roof, then covering the top with a big mound of soil. The doorway may have bulkhead doors or an entry way with additional doors. The more modern version is to construct an insulated cellar in the basement of a building such as a CSA distribution barn or your house. See the Bubels’ book, or the Washington State publication for drawings and instructions on making these. Provide wide doorways with ground-level access if possible (roll that garden cart right in!). Good lighting and drainage are important, so you can see if everything is storing well, or hose the shelves and floor down if it isn’t. Mouse-proofing is worth considering upfront. Our 10’ x 11.5’ (3 x 3.5 m) cellar will hold 360 crates with an ample central path. That’s 10,800 pounds (4900 kg), or around 5 tons (tonnes).

Black snakes control mice in the root cellar. Photo by Nina Gentle

Root Cellar Ecosystem

Store potatoes in a moist, completely dark cellar, ideally at 40°F (5°C), up to 50°F (10°C). Ventilate as needed during times of cool temperatures, to maintain the cellar in the ideal range. We need to actively manage conditions in our root cellar to cure the potatoes and help them store well. We have no automated ventilation, or even ventilation ducts. We simply leave the door open at night when we want to cool it down, or in the daytime in winter. We just choose a time when the forecast temperature is in the range we’re aiming for. Yes, mice do come in the open door! We encourage black snakes to live in our cellar, to keep the mice under control. (How do we encourage snakes? I mean we don’t drive them out, and if we need to, we move one or two in there.) This can be a bit unnerving, as the cellar is dark. (We chose not to have a light, as leaving it on by accident could cause a lot of potato greening before we noticed our mistake.) We have developed a special door-opening technique so we can co-exist with the snakes, who like to hang out on the top of the doorframe. We unlatch the door, open it a crack, then bang it closed, before opening it fully. Any resting snakes have by then dropped to the floor where we can see them and avoid them. (No snakes have been hurt in this process!) People who don’t like snakes will be really motivated to fit a rodent-proof vent system!

I wrote a blog post about Root cellar potato storage, on 8/07/2018. It includes a fuller version of our Root Cellar Warden instructions below. Here is the shorter, post-harvest version of our “Root Cellar Warden” instructions:

After the potato harvest, the potatoes need to be at 60-75F (15-24C) with good ventilation for two weeks. Leave the door open on mild nights (or days) every 2 or 3 days, and close it later. The newly harvested potato is still respiring and needs fresh air. Lack of sufficient oxygen during curing results in Black Heart, a condition where the tubers develop nasty black lumps of dead tissue in the centers, so be sure to provide good ventilation during curing.
After 14 days, the potatoes need sorting to remove Use First and Compost ones. Usually this is done by bringing the crates outdoors. You will need buckets, rags, gloves. It’s important to do this in the 3^rd week after harvest, and not leave it longer, to minimize the spread of rot. Keep the crates away from walls, which sometimes collect condensation. The potatoes benefit from the airflow if they are not touching the walls.
After 14 days, cool the cellar whenever a mild night or chilly day is forecast, down to 40-45F (4.5-7C).

Sorting potatoes two weeks after harvest.
Photo Wren Vile

Dormancy Requirements of Potatoes

We researched the dormancy requirements of potatoes in an effort to store ours so they don’t sprout when we don’t want them to.

What I know so far about dormancy is that potatoes need a dormancy period of 4-8 weeks after harvest before they will sprout. So if you plan to dig up an early crop and immediately replant some of the potatoes for a later crop, take this into account. Get around this problem by refrigerating them for 16 days, then chitting them in the light for 2 weeks. The company of apples, bananas or onions will help them sprout by emitting ethylene.

To avoid sprouting, keep the potatoes below 50F (10C) once they are more than a month from harvest, avoid excess moisture, and avoid “physiological aging” of the potatoes, caused by stressing them with fluctuating temperatures, among other things. If eating potatoes do start to develop sprouts, it’s a good idea to rub off the sprouts as soon as possible, because the sprouting process affects the flavor, making them sweet in the same way that low temperatures do.

I have also written blog posts about

Potato Research on Harvest and Storage,

What Makes Potatoes Sprout,

How to Deal with Green Potatoes (one of my most-read blog posts!)

and if you still want to read more about potatoes,

Book Review “Potato: a history of the propitious esculent” John Reader, Yale University Press 2008

Read a whole book about the potato. Abe Books, John Reader

Organic and Alternative Methods for Potato Sprout Control in Storage

Mary Jo Frazier and colleagues at the University of Idaho Extension, in 2004, researched the use of essential oils of mint and cloves to inhibit sprouting in storage. These plant oils can add 20-30 days storage, and then need to be reapplied. There is the issue of flavors carrying over into the tubers.

Other biocontrols to reduce storage losses

There has been some USDA ARS (Agricultural Research Service) research into biological disease control for stored fruit and vegetables. It takes three directions:

Using biologicals such as Aspire yeast, Bio-Save Bacteria (Pseudomonas syringae) or chitins to form a semi-permeable film over the surface of the roots and fruits;
UV light to induce rot resistance. Primarily used for fruit;
Natural fungicides derived from jasmine and peaches, which induce disease resistance in the crop itself.

Currently these methods are only used by large operations, but in the future, they may be useful to small growers.

Harvesting potatoes

This is the fourth part of a monthly series on growing potatoes, a dietary staple.

PART ONE: Planting potatoes (April)

PART TWO: Growing potatoes (May)

PART THREE: Potato pests and diseases (June)

PART FOUR: Harvesting potatoes (This one, July)

PART FIVE: Storing potatoes (August)

PART SIX: Planning to grow potatoes again (September)

I have a whole chapter about potatoes in Sustainable Market Farming, where most of this information can be found.

See Root Crops in June for info on digging up new potatoes, if you can’t wait for them to mature! Harvest for immediate use anytime you’d like after the tubers reach a big enough size.

Picking up lifted potatoes and crating them.
Photo Nina Gentle

Preparing for potato harvest

When the leaves start to turn pale, the plant has finished its leaf-growing stage and will be putting energy into sizing up the tubers under the ground. Avoid irrigating at the end of the growing period or the potatoes may develop hollow heart, make knobby secondary growths or even crack. For maximum yield, and to harvest for storage, wait until the tops are completely dead.

In England, we planted in spring and harvested in October, waiting for the frost to kill the vines. In Virginia, we plant in March and June, harvesting in July and October. For our unmulched March-planted July harvest, we mow two weeks before our planned harvest, to fit a tight crop turnaround. In hot weather the cut tops and weeds dry up. If more weeds grow, we mow again the day before harvest. For our fall-harvested crop, planted and mulched in June, we need to remove the mulch after the mowing and before the harvest. This is a slow job, but necessary, and the mulch makes a good addition to our compost pile. If it looks like rains will delay the harvest, or nights are forecast to be very frosty, we delay de-mulching until the day before harvest.

Varieties such as Red Pontiac, Yukon Gold and Kennebec are determinate — they grow as a bush, then flower and die. If you have indeterminate varieties such as Russet Nugget, Nicola, German Butterball or Elba, you will need to kill the vines. I’ll come back to the topic of determinate and indeterminate varieties in Part Six, Planning to grow potatoes again (September). You can bring about an early vine death by mowing or flaming. This will also remove weed growth that could interfere with your digging equipment.

Potato harvest in progress. Note the line up of garden carts to haul away the bounty. Photo Nina Gentle

Whether the vines die naturally at the end of their lifespan, or they die of disease, or the frost kills them, or you do it yourself by mowing or flaming, it helps storability to wait 2-3 weeks more before harvesting to allow the skins to toughen up. They become more resistant to scrapes and bruises) and the potatoes become higher in dry matter. Harvesting is also easier if the vines are well dead. Test by digging up a sample and rubbing the skins. When the skins don’t break, the potatoes are storable.

Be sure to have enough crates, buckets, totes, gloves and workers. Clean and air the root cellar and warm it to 70°F (21°C).

Harvesting your potatoes

If possible, harvest when the soil moisture is 60-80% of field capacity. Not too dry, not too wet. This reduces damage from scraping. Ideally the soil temperature will be 45°-65°F (7°-18°C). Because soil temperature lags 3-4 hours behind air temperature rise each day, in cold weather, try to harvest late in the day, but with time to finish before dark. In hot weather, harvest in the morning as early as possible. Tuber temperature will also affect bruise and rot susceptibility. Do not harvest when tuber temperatures are below 45°F (7°C) or above 85°F (30°C).

To use our potato digger we have to remove the mulch first.
Photo Twin Oaks Community

We use a Checchi and Magli single-row side delivery SP100 harvester. It does a good job in clean soil and an excellent job in clean fairly dry soil but gets stuck if we have a lot of organic material on the soil (weeds or mulch). The 1-row Potato Digger from US Small Farm Equipment, which a neighboring farm bought, has the same challenge. If using a digger, don’t set it too deep, or too much soil will be dumped on the harvested potatoes.

During harvest, someone walks alongside the tractor with a long-handled hook/claw tool, to clear blockages and hook any potatoes from the path of the tractor wheels. The rest of the crew follows, picking up and sorting the potatoes. If they are wet, we leave them to dry for a short time. We sort the damaged ones into “Farm Use” buckets and crate up the good ones. We try not to leave any potato parts in the field, to reduce the chance of spreading diseases.

When freshly harvested, potatoes are tender, breathing things. Avoid bruising, which is damage that does not break the skin, by not dropping potatoes more than 6” (15 cm), or throwing them towards a container. Don’t bang them to knock off extra soil. In hot weather we aim to work until done and not leave any potatoes in the field baking for long. In cold weather we aim to get done before nightfall and not have any freeze overnight!

Chain of people moving crates of potatoes from the truck to stack under a big pine tree.
Photo Nina Gentle

When harvesting in summer, we stack the crates of potatoes covered with a tarp, under a big tree overnight to lose some of the field heat before moving them to the root cellar early next morning. For the fall harvest, if the weather is chilly, we take the crates straight into the root cellar. Potatoes you take from storage can be no better than the quality of the potatoes you put into storage!

Potato harvesting raises rocks to the surface, so we try to find time soon after the potato harvest to collect them for use in road repairs and construction.

Yields are likely to be 150 lbs/100ft (223 kg/100m); 200 lbs/100 ft (300 kg/100m) or more is a good yield; double this is possible. In my book Sustainable Market Farming, in the potato chapter, I made a mistake and gave these as pounds per acre, which would be a miserable yield! 5 gallon buckets and square plastic “milk” crates hold about 30 lbs each (14 kg)

Post-harvest two week curing

After harvest, potatoes need to cure for two weeks at a surprisingly warm temperature: 60°F–75°F (15.5°C–24°C), and 95% humidity. While curing, the root cellar will need 6-9 hours of ventilation every two or three days. The potatoes are still actively respiring, so they need a good oxygen supply. Failure to ventilate enough can lead to Blackheart, where the inner tissue of the potatoes dies and turns black.

Potatoes will heat up if left closed in. Ventilate when the temperature is 0-20 F° (0-11 C°) cooler than your goal: air in the daytime if nights are too cold and days are mild; at night if nights are mild and days too warm. Try hard to avoid having the cellar cool down, then warm up. That causes the potatoes to sprout. If there is too much condensation, use a fan and open the cellar doors, when temperatures are closest to the goal. During the curing period, the skins toughen up more, and cut surfaces and superficial wounds heal over, enabling long-term storage.

Sorting potatoes in early November.
Photo Wren Vile

Sorting and preparing for long-term storage

After two weeks, we sort through the whole storage crop for rot, We find that this single thorough sorting can remove almost all of the storage problems that are going to happen. Not sorting at this point lets rots spread.

After the curing period, the potatoes become more dormant and do not respire so actively. Fresh air is needed about once a week in weeks 2-4, after which air exchange is not needed. Relative humidity should be 90-95%, to keep weight loss to a minimum, but not 100%! If the cellar is too warm, you will need to ventilate to lower the temperature.

Once potatoes are more than a month from harvest, the temperature, should be 40°-50°F (4.4°-10°C), and closer to the lower end of the range is best for long-term storage. In summer we work hard to reduce the temperature to 50°F (10°C) for long-term storage, but in the winter we can reach 40°F (4.5°C). Constant temperatures or a steady decline is the goal, not dramatic fluctuations, as these can cause stress and physiological aging, which leads to sprouting. Hotter temperatures promote more rot, and age the potatoes faster, also leading to early sprouting.

Potatoes have a natural dormancy of 60-130 days (depending on the storage temperature). After that period, they will start to sprout.

I will address long-term storage and preventing sprouting in Part 5 next month.

Resources

The Potato Association of America, Commercial Potato Production in North America 2010.

2016 Organic Production and IPM Guide for Potatoes from Cornell has a big focus on dealing with diseases and pests.

Don’t let your potatoes sprout in storage (more next month)
Photo Jesse Strassburg

Potato Research, Mother Earth News Fair PA and Heritage Harvest Festival

Crates of potatoes in our root cellar.
Photo Nina Gentle

Potato Research on Harvest and Storage

Last week I mentioned that while researching potato yield figures, I found an interesting publication, The Potato Association of America, Commercial Potato Production in North America 2010. I’ve been reading that and learning more about potatoes. Here I’m going to focus on harvest and storage, because that’s the bit we’re currently challenged by. I also learned more about planting in hot weather, but that’s for another time.

In England we planted in spring and harvested in October, waiting for the frost to kill the vines. In Virginia we plant in March and June, harvesting in July and October. We have grown Red Pontiac, Yukon Gold and Kennebec here, mostly. They all seem to be determinate varieties. I only just learned there are determinate (varieties with naturally self-limiting growth, generally “early” varieties) and indeterminate varieties (such as “Russet Nugget,” “Nicola,” “German Butterball” and “Elba”). The distinction is explained in Potato Bag Gardening. Growers using towers, grow bags, and cage systems want indeterminate potatoes, which continue to produce more layers of tubers on the stems as they are progressively covered with more soil. Growers wanting a fast reliable crop in the field mostly choose determinate types, which grow as a bush, then flower and die. The Wild Woolly Web does seem to have some contradictory statements about which varieties are determinate and which indeterminate, and some dedicated container growers make assertions not supported by experienced commercial growers. So Reader Beware! I trust Extension and here’s a link to their Ask an Expert page on potato types, and the University of Maryland Extension Home and Garden Info Center Potatoes.

June-planted potatoes in early September
Photo Kathryn Simmons

Whether the vines die naturally at the end of their lifespan, or they die of disease, or the frost kills them, or you kill them yourself by mowing or flaming, the potatoes will store better if you then wait 2-3 weeks before harvesting. The potato skins thicken up (becoming more resistant to scrapes and bruises) and the potatoes become higher in dry matter. Harvesting is easier if the vines are well dead. We generally bush-hog ours. Decades ago, in England, we had late blight in the middle of the season, and we cut the tops off and made a very smoky bonfire. (I wouldn’t participate in that much air pollution nowadays!) After waiting for a couple of weeks for the late blight spores to die, we dug the potatoes. The idea was to prevent spores getting on the tubers. As I remember, it all worked out OK.

If at all possible, harvest when the soil moisture is 60-80% of field capacity. Not too dry, not too wet. This reduces damage from scraping. If using a digger, don’t set it digging too deep, or too much soil will be damped on the harvested potatoes.

Tuber temperature will also impact bruise and rot susceptibility. Ideally soil temperature will be 45-65F (7-18C). Because soil temperature lags 3-4 hours behind air temperature rise each day, in cold weather, try to harvest around 6 pm or a bit later. In hot weather, harvest in the morning.

When harvesting in summer, we stack the crates of potatoes under a big tree overnight to lose some of the field heat before moving them to the root cellar early next morning. Potatoes you take from storage can be no better than the quality of the potatoes you put into storage!

The first part of the storage period is the curing. The potatoes are still actively respiring, so they need a good oxygen supply. Failure to ventilate the cellar enough can lead to Black-heart, where the inner tissue of the potatoes dies and turns black. During the curing period, the skins further toughen up, and cut surfaces and superficial wounds heal over, enabling long term storage. The temperature should be as close to 50-58F (10-14.4C) as you can get. The lower end of the range is best for fresh eating (as opposed to junk food manufacture). Hotter temperatures will promote more rot, and age the potatoes faster, leading to early sprouting. Relative humidity should be 90%, but not 100%! If there is too much condensation, use a fan and open the cellar doors, when temperatures are closest to the goal. Curing takes 10-14 days.

We find that a single thorough sorting after 14 days can remove almost all of the storage problems that are going to happen. Not sorting at this point lets rots spread.

After the curing period, the potatoes become more dormant and do not respire so actively. They don’t need as many air changes as during curing, but if the cellar is too warm, you will need to aerate more. The temperature during the storage period should be 40-50F (4.4-10C), and closer to the lower end of the range is best. Constant temperatures or a steady decline is the goal, not dramatic fluctuations. Humidity should still be 90-95%, to keep weight loss to a minimum.

Potatoes have a natural dormancy of 60-130 days (depending on the storage temperature). After that period, they will start to sprout. Some plant extracts, including clove oil, can add 20-30 days storage, and will then need to be reapplied. I do not know anything about this myself, and do wonder how you remove the clove flavor from the potatoes!

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Speaking Events

I have two speaking events coming up in September

2019 Mother Earth News Fair Pennsylvania.

September Friday 13- Sunday 15, 2019

Location: Seven Springs Mountain Resort, 777 Waterwheel Dr., Seven Springs, Pa. 15622

I am giving two 60 min workshops

Hoophouse winter lettuce: Green Forest, and Red Salad Bowl, two of our fifteen varieties.
Photo Wren Vile

Lettuce Year-Round on Friday 9/13 12.30-1.30 pm at the Grit Stage

This presentation includes techniques to extend the lettuce season using row covers, cold frames, and hoop houses to provide lettuce harvests in every month of the year. The workshop includes a look at varieties for spring, summer, fall, and winter. Pam Dawling considers the pros and cons of head lettuce, leaf lettuce, baby lettuce mix, and the newer multileaf types. She also provides information on scheduling and growing conditions, including how to persuade lettuce to germinate when it’s too hot.

Cool Season Hoophouse Crops on Saturday 9/14 3.30-4.30 pm at the Building and Energy Stage

Learn how to fill your hoop house with productive food crops in the cool seasons. Pam Dawling discusses suitable crops, cold-hardiness, selecting crops, calculating how much to harvest and how much to plant, crop rotation, mapping, scheduling, seasonal transitions, succession planting, interplanting, and follow-on cropping.

Book-signing at the Bookstore Saturday 4.30-5 pm. Buy new books at the Bookstore and bring your grubby used copies to be signed too!

Demos at New Society Publishers booth, of tomato string-weaving and wigglewire system for fastening hoophouse plastic to framework
Friday 3 -3.30 pm, 4.30-5 pm; Saturday 10-11 am, 1.30-2.30 pm; Sunday 9-10 am. 1-2 pm, 3.30-4 pm

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Heritage Harvest Festival, Monticello, Charlottesville, VA

September Friday and Saturday 21-22, 2019

Buy tickets online

Workshop with Ira Wallace

10:30 – 11:30 am Saturday in the Heritage Tent

Winter Gardening: No Tech to High Tech

Learn tips on growing cold-hardy vegetables (not only kale!) out in the open and with varying degrees of protection from rowcovers, low tunnels, coldframes and hoophouses (high tunnels). We’ll consider crop choices, planting dates and harvesting so there’s always something to eat for everyone from winter market gardeners to small backyard growers. We’ll explain ways to maximize production with succession planting and follow-on cropping.

No extra fee for the workshop, included with the price of general admission

Booksigning: SATURDAY, SEPT. 21^st, 11:45am – 12:15pm, MONTICELLO SHOP TENT (WEST LAWN). Buy new books at the Bookstore and bring your grubby used copies to be signed too!

December view in our hoophouse, showing lettuce mix and turnips.
Photo Wren Vile

What Makes Potatoes Sprout?

“White” or Peruvian potatoes (sometimes called Irish potatoes) are stem tubers in the nightshade family; sweet potatoes are root tubers in the Morning Glory family. This article is about Peruvian potatoes, not sweet potatoes.

Curing potatoes

Potatoes are cured enough for storage when the skins don’t rub off. It’s best to leave the potatoes in the ground for two weeks after the tops die, whether naturally or because of mowing, if you want them to store. When the potatoes are harvested after the skins have toughened, there will be less damage during harvest. Curing allows skins to harden and some of the starches to convert to sugars. These changes help the tubers to store for months.

When potatoes first go into storage, they are still “alive” and respiring, and need fresh air frequently. They will heat up if left closed in, and could develop black centers, where the cells die from lack of oxygen.

Storing newly harvested potatoes

For the first two weeks after harvest, the root cellar or other storage space will need 6-9 hours of ventilation every two or three days. The temperature goal is 60°F–75°F (16°C–24°C), with 95% humidity. Ventilate when the temperature is 0–20F (0–11C) cooler than your goal: in the daytime if nights are too cold and days are mild; at night if nights are mild and days too warm. If it is very damp in there, ventilate more.

Two weeks after harvest, sort all the potatoes. By this time, any which are going to rot have likely started doing so. Restack, remembering to keep airspace between the crates and walls. For weeks 2–4, the temperature goal is 50°F (10°C) and fresh air is needed about once a week.

Long term potato storage

After week 4 in winter, cool to 40°F (5°C); in summer, below 50°F (10°C). Ventilation for air exchange is no longer needed, as the tubers have become dormant. The final long-term storage conditions are cool and fairly moist, 40°F–50°F (5°C–10°C), 85%–90% humidity—a root cellar is ideal. Below 40°F (5°C) some starches convert to sugars, giving the potatoes a bad flavor and causing them to blacken if fried. Try hard to avoid having the cellar cool down, then warm up. That causes the potatoes to sprout.

Pre-sprouting seed potatoes

Potatoes have a dormant period of 4–8 weeks after harvest before they will sprout. The warmer the conditions after dormancy ends, the quicker they will sprout. If you want potatoes to sprout during the dormant period, trick them by refrigerating for 16 days, then pre-sprouting them in the light.

We routinely “chit” or pre-sprout our seed potatoes before planting. Bring the seed potatoes into a warm, well-lit room around 65°F–70°F (18°C–21°C) and set them upright in shallow boxes, rose end up, stem (belly-button) down, for 2–4 weeks in spring, 1–2 weeks in summer. For summer planting, store your seed potatoes in a cool place at 45°F–50°F (7°C–10°C) until 2 weeks before your planting date, then sprout them.

Seed potato pieces after pre-sprouting for planting.
Photo Kati Falger

The effects of ethylene

Ethylene is a naturally occurring, odorless, colorless gas produced by many fruits and vegetables, but it can also be produced by faulty heating units and combustion engines. Propane heaters should not be used, as propane combustion produces ethylene. Incomplete combustion of organic fuels can result in the production of carbon monoxide, ethylene and other byproducts. Do not use any unvented hydrocarbon fuel heaters near stored produce.

Ethylene is associated with ripening, sprouting and rotting. Some crops produce ethylene in storage—apples, cantaloupes, ripening tomatoes, already-sprouting potatoes all produce higher than average amounts. Chilling, wounding and pathogen attack can all induce ethylene formation in damaged crops.

Some crops, including most cut greens, are not sensitive to ethylene and can be stored in the same space as ethylene-producing crops. Other crops are very sensitive and will deteriorate in a high-ethylene environment. Potatoes will sprout, ripe fruits will go over the top, carrots lose their sweetness and become bitter.

Summary: Potatoes are more likely to sprout if they are more than 4–8 weeks after harvest; in the light; near fruits, vegetables, flowers or malfunctioning propane or natural gas heaters that produce ethylene; too warm, or warm after being cool. Potato sprouts are toxic, see my earlier article.

How to deal with green potatoes

Green skinned potatoes. Credit Wikipedia File:Groene_aardappels_'Doré'_(Solanum_tuberosum_'Doré').jpg — Green skinned potatoes.
Credit Wikipedia File:Groene_aardappels_’Doré’_(Solanum_tuberosum_’Doré’).jpg

For a few years, we have had trouble with too many of our June-planted, October-harvested potatoes having green patches. We’ve been discussing what to do, and trying to separate myth from reality. How can we minimize the amount of green patches on our potatoes? How should we deal with them when they happen? How poisonous are green potatoes?

Here’s what seem to be the facts:

The green is chlorophyll, caused by the tubers being exposed to light. Chlorophyll is not poisonous. But the same conditions that promote chlorophyll formation also increase the production of solanine, which is poisonous.
It’s also possible for potatoes to have increased levels of solanine without being green, for example, if diseased or damaged or stored under warm temperatures or after experiencing spring frost (and making stunted growth as a result). Potato sprouts are also high in solanine. An unpleasant bitter taste indicates an increased level of solanine.
The Lenape potato was developed in the 1960’s to make beautiful golden potato chips (it’s challenging to to reliably make good chips without burning them.) It was pulled from the market in 1974 after studies showed that Lenape produced an extraordinarily high level of solanine.
Simply removing all green-skinned potatoes won’t remove all solanine from our diets. Solanine is a glycoalkaloid found to some extent in all nightshades. Other commonly-consumed alkaloids include caffeine, nicotine and cocaine.
Solanine is one of the plant’s natural defenses against pests and diseases, such as late blight.
The amount of solanine in an average portion of potatoes is easily broken down by the body and excreted. “[S]olanine levels in the blood are low after ingestion due to poor absorption by the gastrointestinal tract. Second, it is removed from the body fairly rapidly in both the urine and the feces, usually within 12 hours, preventing accumulation in the tissues. Third, intestinal bacteria aids in the detoxification by hydrolyzing the glycoside into solanidine(aglycone), which is less toxic than solanine and also poorly absorbed.” Andrew Montario, Cornell University
“Solanine levels above 14mg/100g are bitter in taste. Cultivar[s] with greater than 20mg/100g cause a burning sensation in the throat and mouth.” Andrew Montario, Cornell University
2-5 mg of solanine per kilogram of body weight can cause toxic symptoms. 3-6 mg per kilogram of body weight can cause death.
A normal potato can contain 8 mg of solanine or 12-20 mg of total glycalkaloids per kilogram of potato.
So to get 2 mg per kg of body weight, a 100 lb (45.35 kg) person would have to eat about 90 mg of solanine, or at least 11.25 kgm (about 25 lbs) of regular potatoes.
Green tubers contain 250-280 mg/kg of total glycoalkaloids. The make-you-sick dose of 90 mg of solanine for the 100 lb person could be found in 0.6 kg (about 1.25 lbs) of green tubers. That’s green-all-over potatoes.
Alexander Pavlista at the University of Nebraska, Lincoln says that a 100 lb person would have to eat about one pound of fully green potatoes to get sick. That is equivalent to one pretty large baked potato. His report recommends cutting away the green parts.
Green skins contain 1500-2200 mg/kg total glycolkaloids.
Potato shoots can contain 2000-4000 mg/kg of glyclakaloids. These figures are from Is It Safe to Eat?: Enjoy Eating and Minimize Food Risks, by Ian Shaw
The toxic dose seems to depend on the individual’s tolerance as well as the ratio of solanine consumed to the rest of the potato. 30-50 mg/100 gm; 24 mg/100 gm, 40 gm/100 gm seems to be the range in green-skinned potatoes, from various reports. See, for example, The Smithsonian article of October 21 2013 by K Annabelle Smith.
The symptoms of solanine poisoning include gastro-intestinal problems, and, more worryingly, neurological disorders.
Most victims of solanine poisoning make a full recovery.
Fatalities are generally restricted to people who don’t get treatment, or were undernourished to start with.
According to the British Medical Journal 8 December 1979, there is normally a high concentration-gradient between the peel and the flesh, but this is lost when potatoes are exposed to light or stored in adverse conditions.

Potatoes being harvested. Credit Kathryn Simmons — Potatoes being harvested.
Credit Kathryn Simmons

Here’s what’s disputed:

Some studies have shown correlation between pregnant women eating potatoes suffering from Late Blight (which increases levels of solanine and other glycoalkaloids) and spina bifida in the fetus. But other studies have found no correlation between birth defects and consumption of potatoes.
The US National Institutes of Health says never to eat potatoes that are green under the skin.This has been variously interpreted to mean: throw out all potatoes with any green or cut off the green bits and eat the rest or cut off the green skin and also any green flesh under the skin. Most people seem to cut off the green bits and use the rest.
“Solanine is fat-soluble, so deep-frying reduces the danger.” The Department of Animal Science at Cornell University says that solanum-type glycoalkaloids are not destroyed by cooking.
“Solanine is water-soluble, so boiling lowers the levels.” An infamous 1979 case of 78 London schoolboys getting very sick after eating boiled potatoes that had been stored improperly for several months, seems to prove this belief not true. (All made a full recovery.) Results of a study by Takagi, Toyoda, Fujiyama and Saito “confirmed the relatively high stability of CHA [alpha-chaconine, the other main alkaloid in potatoes] and SOL [solanine] in potatoes under normal home cooking conditions.”
“Eating nightshades makes arthritis worse.” This seems to be an entirely different issue, as no source lists arthritis as a symptom of solanine poisoning.

Mulched June-planted potatoes. Credit Kathryn Simmons — Mulched June-planted potatoes.
Credit Kathryn Simmons

Here’s what seems wise:

When growing potatoes, try to cover them adequately with soil and/or mulch, so that they are not exposed to light. Give enough space between plants so that tubers are not crowded and pushed up above the soil surface.
When mowing to reduce weeds before mechanical harvest, keep to a minimum the length of time between mowing and harvest. Likewise time between removing mulch and mechanical harvest. Manual harvesting can be done without removing weeds or mulch first, but there is a limit on how big of an area one person can hand-harvest well.
When harvesting, minimize damage.
When preparing for storage, do not gather all the potatoes showing any green into one container. Leave the green ones distributed among the others, so that no-one gets a higher level than normal. There is apparently no reason to use green potatoes sooner than others. Nor is there apparently any advantage to keeping them in hopes of de-toxifying them.
When storing, keep potatoes in the dark, and cool. Don’t store them for longer than necessary. Generations of potato growers have provided for their family needs for a whole year from one planting, so there seems no need to worry about storage up to one year or so.
When preparing potatoes for eating, cut off the green bits. Don’t use all the greened potatoes in the same meal. Reduce the risk by reducing the ratio of greened to non-greened potatoes.
When eating, spit out any potato that tastes bitter.
Enjoy eating your potatoes fried, boiled, mashed, chipped, baked, roasted. .

Our root cellar. Credit McCune Porter — Our root cellar.
Credit McCune Porter

Potato and tomato yields, VABF Conference, weather extremes.

Potato harvest October 2014. Credit Nina Gentle.

We got our June-planted potato harvest finished last week, and I counted the crates – 122. That makes 3660 pounds, a pretty good amount for the space we used. The Red Pontiac seem to have done a whole lot better than the Kennebec – the same result we got from our March-planted crop. One thought is that maybe the Kennebec seed pieces were cut too small, although I’d be surprised if the whole crew managed to do the same thing twice.

We use discarded plastic crates for our potatoes. They are lightweight, stack easily and don’t grow mold. We store our crop in our root cellar, which is built into the ground, a kind of constructed cave. Nice, fossil-fuel free and low-tech. And, like natural caves, it is prone to damp. It’s prone to mice too, but we have our organic solution to that problem: a black snake lives in there. We have been known to commandeer a snake, if none has chosen to move in. It’s a good winter home for snakes

Our organic pest mouse remover. Credit Nina Gentle — Our organic pest mouse control expert.
Credit Nina Gentle

We also tallied our Roma paste tomato harvests for the year. We gathered 313 5-gallon buckets. If we’d had more workers we could have harvested more. Our plan was to harvest the whole patch of 530 plants twice a week, but during the peak of the season we were lucky if we could get one half harvested each time.The plants stayed in good health throughout the season, and the fruit stayed a good size. This is thanks to the selection work I have been doing when we save our seed (Roma Virginia Select). Also thanks to drip irrigation we have reduced water splashing on the leaves, which can spread fungal spores.

Geek Special: See our harvest data here:Roma Harvests

Roma is a determinate variety, meaning the number of trusses (branches) of fruit is genetically predetermined, but as with many crops, the more you pick, the more you get. Leaving mature fruit delays development of immature fruit. I have not found anyone to tell me how many trusses of fruit Roma has, and despite growing 530 plants each year for over 20 years, I have never taken the time to count them. Maybe next year. . .

If you read descriptions of determinate tomato varieties, you would think they are all tiny plants with a three-week harvest window. Roma is a large determinate, at least 4ft tall, and our harvest period lasts from mid-July until frost (usually late October here). Our peak period is about a month (early August to early September). Here’s a general description from www.seedaholic.com: “Determinate varieties are generally smaller and more compact than indeterminate tomatoes. . .”

The Twin Oaks Garden Crew is getting ready to have our annual Crop Review meeting. We work our way down an alphabetical list of crops, noting what worked and what didn’t. And at the same time, we pop our garlic bulbs into separate cloves for planting.

My next speaking engagement is at the Virginia Biological Farming Conference January 30 and 31 2015, with pre-conference sessions on Thursday January 29. Online registration is now open. I’ll be presenting my workshops on Asian Greens and Succession Planting for Continuous Harvests. Lots of other great workshops too, including from Jean-Martin Fortier. Follow the link to get to my book review of The Market Gardener.

If you looking for a chatty online group of homesteaders, try Earthineer or, of course, the Mother Earth News blogs (I write for the Organic Gardening Blog)

Guess which was our hottest day this year: September 2? July 2? June 18? May 26? I recorded 97F, 98F, 98F and 90F. August didn’t get a look in! June 18 tied with July 2. And our wettest day was April 29, with 3″. Hurricane season didn’t bring us anything to blog about. I’m not complaining!

Crop Planning presentation, weather and resilience

<div style=”margin-bottom:5px”> <strong> <a href=”https://www.slideshare.net/SustainableMarketFarming/crop-planning-60-min-presentation” title=”Crop Planning. Pam Dawling 60 min presentation” target=”_blank”>Crop Planning. Pam Dawling 60 min presentation</a> </strong> from <strong><a href=”http://www.slideshare.net/SustainableMarketFarming” target=”_blank”>Pam Dawling</a></strong> </div>

My presentation on Crop Planning to the CSA Expert Exchange Online Conference on Friday 3/7 went well, after a short delay due to slow website loading. Joys of rural living! I just learned that our Internet runs slow on rainy days because the water in the soil affects the underground cables. A s a farmer, I’m very used to considering the effects of the weather, But I never would have guessed this one. Now I realize I jinx myself when I work outside in nice weather and do my desk work while it’s raining!

Spinach bed with a row of peas in the middle. Photo — Spinach bed with a row of peas in the middle.
Photo Kathryn SImmons

This week has been challenging in the garden because of snow followed by very wet soil. On Monday we managed to transplant a bed of spinach and the first week’s round of lettuce. That felt like great progress! Even though it is a month later than we would “normally” hope to do those tasks! We chose to work on the driest section of the raised bed area. Before that we had been weeding the grapes and spreading compost. Having some perennials to take care of makes good use of our time in the winter, early spring, and whenever cultivated soil is too boggy to step on (in).

These considerations are all part of a list we keep to help us choose tasks suited to the conditions, so we can make best use of our time without doing damage. A lot of our garden work is done on 3 or 4 hour shifts with up to 11 people. The honcho needs to be on the ball to keep all those people gainfully employed! Our honchos/honchas are the more experienced people, and will usually prepare for the shift beforehand, making a list of possibilities.

Some of the shift time is harvesting (only spinach currently, apart from getting potatoes from the root cellar and sweet potatoes from the basement). That’s our top priority. We try to get some harvesting done even if it’s very cold or raining lightly. The crops that wilt fastest get picked close to the end of the harvesting period, so they don’t deteriorate while we get other crops.

We have a Task List for the week, and our sequence of priority is generally harvest, plant, mulch, prepare beds for planting, hoe, hand-weed. “Prioritize planting during the planting season” is one of the mantras we embrace. Sometimes other factors come into play. A new member pointed out that all my answers start with “It depends. . . ”

We try to do the more aerobic jobs (especially jobs involving shovels) in the coolest part of the shift, or on the cooler days. We also try to offer each person some options, because people do better when doing tasks they prefer. Sometimes we just have to grin and bear it: “This is the job we need to finish today.”

We are often including visitors in our work, so we need to make sure we mix up members and visitors on each task, so that visitors get enough directions and help. We also need to check in to see how they’re doing with the heat/cold and level of physical activity. We don’t want them to collapse! We also need to be firm about pulling them off a job if they are causing damage, and trying to find some other task that might suit them better.

Having the entire crew finish the shift at the same time is complex choreography! Putting tools away as we go along helps reduce a mammoth task at the end, although having some people cleaning and storing tools as the finish time approaches can be a good way of evening out the workload. The honcho needs to pace the planting, watering and rowcovering. It’s no good transplanting 500 feet if you don’t get it watered and covered before leaving the scene.

Sometimes it’s easier to start everyone on a big hoeing or weeding project, then leave an experienced person in charge of the straightforward task and most of the crew, while you pull out a couple of people to get a complicated task started. Next add more people once it’s up and running. Or send one or two experienced people over to set up, and then send more crew over as the set up work is done It’s awful having 9 people stand there while you try to figure out how to do a planting!.

We have contingency plans for specific situations:

If the day is likely to be very hot, have an “aerobic segment” at the beginning of the shift and get the physically taxing tasks done first (especially anything involving shovels).

If the morning starts out with a heavy dew, postpone harvesting cucurbits, nightshades, strawberries and legumes until the leaves dry, to reduce the spread of disease.

After heavy rain: mulched perennials (fruit and asparagus) are the easiest places to work without getting bogged down. Don’t work in sinking mud, it compacts the soil, which means the plants go short on air, and the soil will be slower to drain after future rains.. Standing on boards is an option for harvesting or planting..

If heavy rain is expected and you might have to stop in a hurry, do weeding, not planting. Don’t hoe if it’s about to rain, it’s a waste of time. Hoeing is best done in an area that won’t get irrigated that night. Likewise don’t leave pulled weeds on the beds before rain. They’ll re-root.

If you feel frazzled, choose a big simple task lots of people can do, like weeding strawberries, or hoeing corn. Or choose two tasks geographically close, so it’s easy to keep an eye on everything happening.

The past few weeks in our garden

I’m just back from vacation. It’s a very lucky farmer who gets two weeks away in the height of summer – one of the benefits of living in community. (See the Twin Oaks website for more on that). The rest of the crew took care of things, and I missed the hottest week of the year (so far). Here’s some of the jobs I missed:

A much delayed planting of the summer potatoes on 7/18 (a whole month later than usual). Our smaller tractor was out of commission for a month, and when it came back, people were lining up to use it. We bought some new furrowers In June, but I missed seeing them in action. Our previous equipment didn’t make deep enough furrows, leading to potatoes popping up above the soil and turning green. We mulch our summer potatoes immediately after hilling, which is immediately after planting, so there is no chance of hilling again later. We like to mulch (with hay) to keep the soil damper and cooler in the hot weather.

Potatoes lifted Oct 09 — An October 2009 picture of our lifted potatoes.
Credit Kathryn Simmons

I also missed the harvest of the spring potatoes. We had hoped to do this earlier too, but mowing the tops was delayed and so the skins didn’t thicken up till 7/22. The potatoes are now safely in the root cellar, and I’m opening the door at night to cool them and to provide fresh air. Newly harvested potatoes are still live plants, still respiring and so still need oxygen. I learned this the hard way years ago, when I didn’t ventilate the cellar enough. The potatoes died in the centers (the condition is called Black Heart). A very disappointing waste of good food. Later the potatoes will go dormant, and won’t need daily air exchanges.

We follow the spring potatoes with the fall broccoli and cabbage, a slightly hair-raising fast turnaround. We have composted and disked the patch, set out driptape, stakes and ropes, rowcover and sticks to hold it down. Because of Harlequin bugs, we need to cover the new transplants for a few weeks until they have the strength to withstand the bugs. So we plant rows 34″ apart, under ropes on stakes. One piece of 84″ rowcover will form a square tunnel over two rows of brassicas. The rowcover is held up by the ropes.

This evening will be the first of many transplanting shifts. Because we are late, the transplants are larger than ideal. Ironically, this year the first sowings germinated very well, grew very well, and the bugs didn’t get under the ProtekNet. Fabulous transplants and they’ve had to wait and wait. Hopefully we can make up for some lost time by really putting our shoulders to the wheel and planting efficiently. having driptape really helps. We turn it on while we plant and so the plants get a drink as soon as they are in the ground. Watering is not a separate job.

While I’ve been away, the eggplants, pickling cucumbers, cantaloupes and okra have all started to produce. We are trying some West Indian Gherkins this year for the first time. I’ll let you know how the pickles turn out. They are strange things, like miniature prickly watermelons. Very prolific, disease-resistant and heat tolerant. The proof of the pudding will be in the eating, though.

Twin Oaks September Garden Calendar

Welcome to Twin Oaks!
Photo by Bridget Aleshire

THE SECOND SPRING

Here’s our Garden Task List for September:

During the month

Weed and thin carrots and brassicas (kale to 12”).

Lettuce Factory: Sow hardy lettuce every 2 days till 21st, (3 rows/planting) then every 3 days. Sow #34-46 this month. Transplant 120 every 3-5 days (1/3 bed) #27, 28, 29, 30, 31, 32, 33 for last outdoor planting (Dec harvest). Transplant #34, 35, 36 9/24-9/30 for frames

Root cellar: air and cool to 60°F by mid-September

Collect seed from Roma tomatoes if necessary.

Screen compost and fill old greenhouse beds before October, for winter lettuce and spring seed compost.

Early Sept: Prepare and plant new strawberry beds if not done in late August, using rooted potted runners or plants carefully thinned from last year’s beds (see August for details).

Transplant collards and kale if necessary. Transplant lettuce #27, 28, 29, 30.

Retrieve spinach and onion seeds from the freezer. After acclimating spinach seeds, sprout 4oz/bed (1 cup/10,000 seeds) for spinach #1 in fridge for one week, then direct sow (if <68°F, and dead nettle has germinated). If still hot, sow (preferably pre-sprouted) spinach in Speedling flats in float tank. 9/20 is last sowing date for fall harvesting. [Could broadcast oats into spinach at planting time for weed control & cold weather protection.]

Sow if not done already: kale and collards by 9/15; turnips by 9/30; radishes, kohlrabi, daikon and other winter radish, miscellaneous fall greens, scallions.

Plant large potato onions this month or early in October, at 8” (wider if supply limited). Cover with ½-1” soil, mulch with hay.

2^nd fall disking: Watermelon plot when 800 have been harvested. Roll up drip tape first, or move to new strawberries.

Mid Sept: 7-14 Sept is the best time to sow vetch & rye, 1:2, 2# of mix/1000 sq ft (75#/acre) on old spring broccoli patch; crimson clover and rye, 1:2, at 55#/acre.

Transplant lettuce #31, 32.

Sow 1^st sowing of hoophouse seedlings (hoop and cover).

Bring 6 tractor buckets compost to hoophouse for fertilizing fall and winter crops.

Move stored onions from basement to fridge, after apples peak in mid-September, and space available.

3^rd fall disking: corn #3, #4, #5. Part of corn #3 plot may be used for new strawberry beds.

Late Sept: Sow spinach #2 for spring harvesting (9/20-9/30), and 2^nd sowing of hoophouse seedlings and cover.

Transplant kale for spring, filling gaps; lettuce #33, finishing up the last outdoor bed; [#34, 35 & 36 in cold frames?] Plant large potato onions (>2”) if not done earlier.

Move garlic from basement to fridge late September-late Oct as needed to make room for winter squash.

Weeding: this is a good catch up time on weeding in the raised beds.

4^th fall disking and seeding: Sow cover crops wherever possible (in unused raised beds too). The last chance for oats is early Sept (9/15??). Can sow winter wheat (winter-killed in zone 4) or winter barley (dies in zone 6) if oat planting date missed. (Oats winter-kill in zone 8). Can sow hardy Austrian winter peas in late Sept at 8oz/100sq.ft. with rye. Can sow red clover this month.

Bush-hog late corn if undersown with oats and soy cover crop.

Perennials: New strawberry beds: Prepare and plant by mid-September if not done in late August. Weed strawberries. Could till up grass in grape alley & sow clover if not done in March. If clover sown earlier, let it seed.

Harvest and store winter squash: Acorn (pepo) types (stem still green, ground spot “earthy” or orange), store 1-4 months; Maximas: Cha Cha, Jarrahdale, Kabocha (stem 75% corky) store 3-5 months; Moschatas: Butternuts, Cheese (peanut colored skin, no mottling or streaks) store 4-8 months, or more. Leave on live vines as long as possible, avoiding frost on fruits. Cut leaving long stem using pruners; handle gently.

September Harvests: Asian melons, asparagus beans, beans, beets and beet greens, broccoli, cabbage, cantaloupes, carrots, cauliflower, celery, chard, Chinese cabbage, corn, cow peas, cukes, edamame, eggplant, horseradish,leeks, lettuce, limas, maruba santoh, okra, pak choy, peppers, hot peppers,radishes, Romas, scallions, senposai, summer squash, Tokyo bekana, tomatoes, turnips, watermelons, winter squash, yukina savoy, zucchini. It is possible to lightly harvest rhubarb during September, if wanted.