Direct-sown vegetable crops

Young rows of September-sown Eat-All Greens in early October. Direct sown in September. Photo Bridget Aleshire

I wrote a post recently that discussed transplanting, mainly as a way to get earlier crops in spring. Now I’m going to write about direct-sowing. This is the word for putting the seeds directly into the ground outdoors.

As with transplanting, some crops are just not going to thrive if you start too soon: cucumbers, peppers, and even tomatoes, for example. Make sure you can provide conditions that meet the minimum temperature requirements for these tender crops. See my book Sustainable Market Farming, for the details, and The Year-Round Hoophouse for a chart of germination temperatures, telling you how many days each crop will take to emerge at various temperatures. Buy a soil thermometer and push the stem all the way into the soil to measure at a depth of 4” (10 cm) I find it helpful to push the thermometer stem through a larger colorful plastic lid, or stake flag. And install it somewhere safe, where it won’t get stepped on, mowed, or tilled up.

Soil thermometer with colorful background to help us keep it safe,
Pam Dawling

March conditions have become more unreliable, often colder. For example, if the soil at 4” (10cm) deep is 40F (4.4C), you might do better to wait if your chosen crop will take more than 21 days. In cold wet soils, seeds can rot rather than sprout. Write down your sowing date and check the soil for emergence. If nothing has come up when it should have, consider resowing. You could rake or till the whole row or bed and start over, or you could hedge your bets and sow new rows in between the original rows. This might mean ending up with fewer rows, or rows closer to the bed edge than you like, but you will be salvaging an unfortunate situation, so it will be better than a crop failure. If the original rows do come up, you can hoe off the new rows, and it won’t have cost you that much time or money. If the original rows are patchy, hoe them off and keep the new ones.

The pros and cons of transplanting and direct sowing

Before you even venture out there to sow seeds, consider the pros and cons of transplanting versus direct sowing, and when each is most appropriate.You can read these in my post about Garden Planning

Young sweet corn plants after imperfect hoeing.
Photo Pam Dawling

How to sow a row of seeds

Find out how deep the seeds should be: bigger seeds go deeper. If you sow too deep, down where the soil is colder, the seedlings will struggle to reach the surface and may fail. Up to three times the seed diameter, is a concept I’ve often read. Not that you need to measure it!

Drag a triangular hoe (warren hoe) or the corner of a regular hoe, along the ground where you want the plants to grow. If your line is not as straight as you like, fill it in and set out stakes and twine. Either use the shadow of the twine as your mark, or eyeball a constant distance from the twine to the hoe. Remember the depth you need. Fix any deep excavations, or superficial scratches.

Preparing to sow Rainbow Chard.
Photo Pam Dawling

Next open the resealable end of the seed packet and pour some out (not over the gum!) into a small dish or the palm of a dry hand. Keep in mind the plant spacing you are aiming for. Radishes, spinach, chard and beets can easily be seen, and sown at one per inch. Avoid the beginner mistake of tumbling many more times the seed you need in the furrow. It causes more work and weaker plants, because they grow up overcrowded, and you will have to thin them. For small seeds, aim at two or three seeds per inch. Really! It’s hard to get good at this skill, but it is well worth learning.

If you mess up, don’t pick up damp seeds and put them back in the packet. They will damage the dry seeds already in there.

Use the hoe or a rake to draw soil in over the seeds to the previous soil level, not mounded up. Next tamp the soil down over the rows, using a hoe or rake on end. This lets the seeds have good contact with damp soil, so they can get the air and water they need.

Cover with rowcover if needed, or if wanted to speed up growth. With rowcover, you will be biding time while spring warms up. The cold weather crops will not benefit from being overheated. Spinach, lettuce and Asian greens will all bolt if their environment in spring is too warm. Read about factors influencing bolting. You will probably have some warmer weather crops going in and you can move the rowcover on those rows.

Use insect netting if you need to protect your vulnerable seedlings from being gobbled up. You will need to remove the netting once flowers appear, so that the crops can get pollinated. If you have serious trouble with a particular pest, look in seed catalogs for parthenocarpic varieties, ones that set fruit without any pollination.

If it doesn’t rain, water the next day (day 2), then whenever the soil surface is dry. It is better to water deeply less often, than to water lightly each day. Light watering may simply not be enough, and will encourage the seedlings to make shallow roots, which will then die back if you don’t water often enough. Deep watering saves water, as a good depth of soil stays wet, and is protected from evaporation by the surface soil. Some people even go so far as to hoe very shallowly to create a “dust mulch” which prevents warm days wicking the moisture out of the soil. For most of use, this is more of a summer issue than a spring one.

Soaking and pre-sprouting seeds

Some larger seeds benefit from soaking before sowing. Peas and beans can be soaked overnight, but smaller seeds need less soaking. Be careful with beet seeds as they can easily drown and rot if soaked for too long.

Pre-sprouting can help with germination when soil temperatures are too cold or too hot for the crop to germinate in a timely way. In spring, if you presprout, be very careful not to overwater the soil until you see the seedlings emerging. This task is not as exacting as growing bean sprouts to eat. You don’t need to rinse them more than once every few days, if that.

To sow soaked or pre-sprouted seeds, first drain off the free water. If the wet seeds tend to clump together in your fingers, either spread the seeds out on a try or a piece of rowcover or similar, until the problem is solved (an hour?) or else mix the damp seeds with a dry, inert, organic dust, such as oat bran, or uncooked corn grits. Some people use dry sand, but if you have a lot to sow, you will find this quite abrasive to your fingers or to the plastic plate of the mechanical seeder.

Station-Sowing Seeds

If your seeds are expensive, or you don’t have many, or the germination is questionable, you can station sow, rather than sowing in a furrow (drill). Simply press a small divot in the soil at the chosen spacing and put about 3 seeds in the hole. Close the soil over the top. This works well if direct-sowing big crops like okra.

Using a push seeder

EarthWay push seeder.
Photo from EarthWay

If you have long rows, you might use an EarthWay type seeder. These inexpensive push seeders are very quick and easy to use, and come with a set of relatively easily-changed plates with holes for seeds of different sizes. They are lightweight and can be used at a fast walking pace.

Market Gardeners will look longingly at the Jang Seeder, which is much more accurate at spacing seeds, and costs an undeniably much larger amount of money. At one time we kept our EarthWay just for carrot sowing (we grew a lot of carrots!), and we used a Planet Junior push seeder for other crops. These are heavy-duty seeders, with plates that are a confounded challenge to change over. In the wrong hands, or on the wrong day, the whole hopper and plate mechanism would fall off. Other people like them for their sturdiness and don’t have the problems I had.

Growers doing no-till seeding might be interested in the very heavy duty Haraka planter I wrote about last year. It is made in South Africa.

Gap-filling with transplants

A special application of direct-sowing is to prepare for incomplete rows emerging, by having some back-up transplants for gap-filling. We have often done this with our first sweet corn, in case the weather turns cold, or cold rain lands on the plot. Sweet corn can be successfully transplanted up to about 2” (5 cm) tall. We sowed ours in Styrofoam Speedling flats. In cold areas, some growers transplant their whole first planting.

Gap-filling in transplanted crops with station-sowed seeds

Another special application of direct-sowing is to fill gaps in rows of transplanted crops when you have no reserve, backup transplants. This only works for fairly fast-growing crops with long harvest periods. You will need to decide if your seeds will have time to reach harvestable size before the transplanted ones are pulled up.

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.

Wow! Weeds!

When we have massive big harvests, it’s hard to get much else done on the garden shifts. This week we’ve made a lot of progress on the two big projects of the broccoli patch and the carrot thinning and weeding.

Cover crop crimson clover flowering 3 — Crimson clover flowers in early May
Photo by Kathryn Simmons

The whole of the broccoli and cabbage patch except the very edges has been cleared of weeds. After tilling the edges, the next job there is to broadcast a mix of medium red clover, large white clover and crimson clover, and water it in until it germinates, if nature doesn’t deal with that. Hurricane Isaac is forecast to curve round towards Virginia by the middle of next week, but lots can change with weather systems. If all goes well, we’ll get the clovers established before we need to start walking in there harvesting (usually mid-September onwards).

This fall (as I reported in my post on July 5) we are taking part in the Novic broccoli variety trials, growing twelve different kinds of broccoli and eleven of cabbage. We have received our report sheets to write down our data and comments each time we harvest them. We’ll benefit from the comparisons and next year just grow the best varieties. We want varieties that provide a long broccoli season, and sideshoots are as important to us as main heads. Quantity and flavor are important to us as well, of course! We want cabbage to store for the winter, as well as cabbage that is ready quickly. We’re feeding the hundred members of Twin Oaks Community, and just about everyone here likes broccoli and cabbage. George Bush would be out of place!

The carrot thinning is making good progress. From the top of the 265′ rows, it looks like we are very, very close to the end. There is what I call a “curvature of the earth effect”: when you walk down there to weed, you see we’re not as close to the end as it seemed. But – the end is in sight! Next, we’ll hoe between the rows, then leave this crop alone until the baby carrots are salad size. Then we’ll weed and thin again, this time to 3″. And we’ll be able to eat those tender little carrots! Then we’ll leave them alone again until November, when we dig and bag them all.

zucchini plant 2 — Happy young zucchini plant
Photo by Kathryn Simmons

So, now we can look at other projects. We are removing rowcover from the crops we sowed at the beginning of August. Today we uncovered a bed of turnips, one of squash, one cucumbers and three kale. In the next few days we can weed and thin those. In fact I already thinned the big squash plants as I walked by on my way to the hoophouse after lunch. I just couldn’t resist! The plants, sown on August 5, are already two feet tall, pushing at the rowcover. I thinned to about 18″-2′ apart, and also pulled out a few handfuls of galinsoga, our most common summer weed in the raised bed area.

One of the signs we look for in deciding whether the season is cooling down enough to sow spinach is the re-emergence of the cool weather annual weeds, especially dead-nettle and henbit. I usually look for them while harvesting paste tomatoes, as that soil has not been disturbed for a while. I saw seedlings of one or other of these key weeds on 8/18 this year, a bit earlier than usual. We were certainly having cooler nights and even cooler days, so it all felt right.

This morning we prepped four beds for spinach. The beds had just been tilled yesterday afternoon with our walk-behind BCS 732, and today we shoveled paths and raked the tops. We’re due to sow 5 beds of spinach on Saturday (9/1), and I’ve already got the seed sprouting in a plastic jar in the fridge. It’s hard to get spinach to germinate in hot weather, so we always pre-sprout in the fall. Just soak the seed overnight, then drain and put the jar in the fridge. I go by once a day to roll the jar so all the seeds get a chance of light and moisture. It’s not much work while they’re sprouting. Hand-sowing is a bit more fussy. Sometimes the damp seeds clump together, so we mix them with a dry, non-sticky food item like dry grits, oatmeal or bran.

We mark five rows in each bed, and sow spinach in the outer four. in spring we sow snap peas in the middle row, and get double value from the bed, the weeding we do, and the winter rowcover.