Alliums for September: plant potato onions, sow ramps, eat Welsh onions, move stored garlic

Potato onion plant with young shoots.
Photo by Kathryn Simmons

Alliums to Plant in September

Divide and replant Egyptian onions and perennial leeks

Divide and replant perennial alliums in September (August-October) to increase the size of the patch and get more next year.

Plant large potato onions (2-2½”, 5-6 cm)

  • It’s better not to try to store very large potato onions over 2½” (6cm) for planting, just eat them (they sprout easily).
  • All large potato onions store poorly, so keep planting stock in the refrigerator until planting in late September or early October. Jeff McCormack does not recommend planting before September.
  • For 360′ (110m) @ 8″ (20cm) you need 540 bulbs plus 30%-40% spare. Approximately 760 bulbs. 150 large bulbs weigh about 25# (11kg)
  • Plant them at 8″ (20cm). If there are not enough large onions available, increase spacing or fill out with medium onions.
  • Cover with ½-1″ (1-2cm) soil, and add 4″-8″ (10-20cm) mulch.
  • Refrigerate any leftovers for November planting with the medium-sized onions, or eat or sell now.
  • Yields can be 3 to 8 times the weight of the seed stock, depending on growing conditions.
  • Individual bulbs can be grown indoors in a pot to produce a steady supply of green onions during the winter.

Sow ramp seeds in woodlands

Mature harvested ramp plants.
Photo Small Farm Central

In zones 3-7, sow ramps seed during August and September (see August blogpost)

Ramps (also known as Wood Leeks or Wild Leeks) are a native woodland perennial, and can be found throughout the eastern-half of the United States, as far west as Oklahoma and as far north as the central and eastern provinces of Canada.

Ramps, (Allium tricoccum) have some of the flavor components of leeks, onions, and garlic. There are projects to re-establish ramps in a number of regions in the Eastern United States.  Carriage House Farm is one such attempt by Grow Appalachia, which is a program of Berea College in Kentucky, Grow Appalachia works with farmers, gardeners, ranchers, and conservationists across a five state area to reintroduce old native and heirloom species of plants.  Ramps is/was one plant in this program. It takes two years for ramp seeds to germinate and another 2-3 years till they hit harvestable levels.

Having Your Ramps and Eating Them Too is a book by Glen Facemire

Alliums to harvest in September

Harvest Egyptian walking onions (topset onions, tree onions) for pickling, leaves of Egyptian onions and perennial leeks (September-April for cutting those)

Egyptian onions produce tiny red-purple bulbs in the umbel instead of flowers, and were previously named Allium cepa var. proliferum. According to Wikipedia, they are now known to be a hybrid of A. cepa and A. fistulosum.

Japanese bunching onion and Welsh onion (native to China, not Wales) are Allium fistulosum. They are sometimes used as scallions, as are some A. cepa bulbing onions. Young plants of A. fistulosum and A. cepa look very similar, but may be distinguished by their leaves, which are circular in cross-section in A. fistulosum rather than flattened on one side.  A. fistulosum has hollow leaves (fistulosum means “hollow”), scapes and does not develop bulbs – the leaves are the part that is eaten. Welsh onions are also known as cibol, chibbles (in Cornwall), escallion (in Jamaica), negi (in Japan), pa (in Korea), as well as green onions, salad onions, spring onions,. These general last names are also used for other kinds of onions where the leaves are the part eaten.

Perennial leeks are Allium Ampeloprasum. Common leeks are Allium ampeloprasum var. porrum (more about leeks in October and March). Elephant garlic is botanically a leek (A. ampeloprasum var. ampeloprasum).

Other Allium Tasks for September

See Alliums for August for more on all of the following jobs which continue into September:

  • Snipping and sorting garlic and potato onions
  • Trimming, sorting and storing bulb onions
  • Eating onions and garlic from storage
  • Inspect onions and garlic at least once a month. Remove bulbs which are sprouting or rotting or else the whole batch may spoil.
  • At the end of September I make the decision about how many potato onions to keep back for planting (see August for our calculations).
  • We also move garlic from warm storage to cool storage (more info below)

Potato onions store very well through the winter so long as they are well-cured, dry, well-ventilated, and not packed over 4″ deep. Ideal conditions are a temperature between either 32–41°F (0–5°C) or 50–70°F (10–21°C) with 60-70% humidity.

Polish White – our softneck garlic variety.
Credit Southern Exposure Seed Exchange

Special Allium Topic for September: Garlic Storage

Before trimming your garlic, I hope you were sure it was fully cured, and you set aside any non-storing bulbs, such as those with damaged cloves, or any over-mature, springing-open bulbs. It usually works to select your seed-stock bulbs at the same time.

Commercially, garlic is stored in the dark at about 32°F (0°C) and 65% humidity, and depending on the species and variety, it may keep six months or more. I have heard that garlic can be stored for up to nine months at 27°F (-2.7°C), but I have not tried that myself. It does not freeze until 21°F (-6°C). Do not store peeled garlic in oil, as garlic is low in acidity and the botulin toxin could grow.

For storage, garlic (like onions) does best with a humidity of 60%–70%. Refrigerators are usually more humid than ideal.

Garlic will sprout if kept in a temperature range of 40–56°F (4.4–13°C), or if it is allowed to get cold then warm. So long as temperatures remain over 56°F (13°C) you can store garlic almost anywhere. You can use an unheated room in your house, a root cellar, garage, etc. Maintain good air circulation. Most varieties store reasona­bly well in a cool room if hung from the ceiling in mesh bags, or spread on shelves in a layer less than 4″ deep.

In our climate, with a long period in the danger zone temperatures of 40–56°F (4.4–13°C), we keep alliums in the warmer storage range (60-70°F (15.5-21°C) or hotter) in a basement until late September or sometime in October when ambient temperatures in the basement drop close to 56ºF (13°C). We then move our eating garlic from the basement to the walk-in refrigerated cooler at 32–41°F (0–5°C), 95–100%. The low shelves in the cooler near the compressor are damper and do not work well. We use the high and dry shelves.

Juggling space for various crops, moving the garlic out of the basement makes space available for the winter squash harvests in September and October. By this time most of the apples from the walk-in cooler have been eaten, and space is available there. Also there is no longer the problem of ethylene emitted by the apples, which causes garlic to sprout. Ideally ripe fruits and garlic would never be in the same storage space.

Softneck garlics store longest. Silverskins store up to 12 months under the best conditions. Most hardnecks last 4-6 months but Music and Chesnok Red can keep 7 months or more here in central Virginia.

Storage of Seed Garlic

We store our seed garlic on a high shelf in the garden shed, at quite variable ambient temperatures, where it does fine until late October or early November when we plant it. Seed garlic does not require long-term storage conditions! The ideal storage conditions for seed garlic are 50-65°F (10-18°C) and 65-70% relative humidity. Storing in a refrigerator is not a good option for seed garlic, as prolonged cool storage results in “witches-brooming” (strange growth shapes), and early maturity (along with lower yields). Storage above 65°F (18°C) results in delayed sprouting and late maturity.

Siberian garlic.
Photo by Southern Exposure Seed Exchange

Alliums for August: plant perennial leeks, eat onion greens, sort potato onions again, move bulb onions into cooler storage

 

Perennial leeks.
Photo by Southern Exposure Seed Exchange

Plant perennial leeks (Oepri, Perlzwiebel)

These will be dry bulbs at this point of the year and can be re-spaced between August and October into a larger planting for next year.

August onion harvests

In cooler climates (if the quality is still good) the tops/greens/leaves of Egyptian onions and perennial leeks can be cut and used fresh. The larger bulbils of Egyptian onions and perennial leeks can be used in mixed pickles. Garlic and bulb onions can be eaten from storage.

Egyptian walking onions.
Photo by Southern Exposure Seed Exchange

Sort potato onions twice in August

Early August: at the third sorting of the potato onions, I separate the clusters, trim the tops and sort by size. Sorting by size is not essential, but I do it to help me figure out what to save for planting and what to eat or use as seed (for planting). We sort smalls (<1.5”), larges (1.5-2.0”) and eaters (>2.0”). And compost material. The rack space required after this stage is only a third of what it was before that.

At the end of August I sort through again, and make initial plans about what to do with surplus planting stock (sell, give to friends). At the end of September I make the decision about how much to keep back for planting. I used to put the onions into net bags for storage, but I found I get better results if I just leave them in a single layer on the racks. The small ones stay there till late January, through freezing conditions (or more accurately, alternating freezing and thawing conditions). They can appear to be frozen solid, but are in fine condition. Ideal conditions are 32-40F, 60-70% humidity, with good ventilation. Layers should not be more than 4” deep.

Yellow potato onions.
Photo by Southern Exposure Seed Exchange

Save seed-stock potato onions

Seed saving is a natural part of growing potato onions. We started in 2000 with 0.5 pound of seed stock, planted late in the spring. We harvested only 1.5#, but we continued, adding in more seed-stock, and planted 46# for 2003, (90’ large, 180’ small). At that point I was dividing into 3 planting sizes: small (<1”, 30-60 bulbs/pound); medium (1-1.5”, 16-22 bulbs/pound); and larges (>1.5”, 7-8 bulbs/pound). For 2004, I planned to plant large:small in a 1:2 ratio by area, to get enough small and medium onions to plant the same area the next year, and to get lots to eat as well. But the 2003 harvest had a high amount of large onions, and I decided to plant them all, increasing to 540’. We expanded to plant 720’, in a large:small ratio of 1:3 by area (i.e. 180’ large, 540’ small). This gives us enough smalls to plant for the next year, and plenty of larges and eaters. Someone growing for maximum seed-stock would probably want to plant a higher ratio of large ones, in order to get more smalls.

Instead of weighing all the onions, I now know I need to save 3 racks (probably 65#, 450 bulbs) of larges (1.5-2.0”) and 5 racks (probably 75#, 2100 bulbs) of smalls (<1.5”) for planting next year’s crop. This allows a margin for decay. The small ones really are very stable, it’s the larger ones that are more prone to sprouting, so I pull those out whenever I pass by.

Australian Brown storage onion.
Photo by Southern Exposure Seed Exchange

Move bulb onions into cooler storage

  • In July I mentioned that bulb onions can safely be stored at 60°F-90°F (16°C-32°C) if they have not been refrigerated at all. This applies only to fully cured onions with dry necks. (Green onions need refrigeration at 32°F-41°F (0-5°C), 95-100% humidity.)
  • For cured dormant onions it is very important to avoid the 45°F-55°F (7°C-13°C) range, because that’s when they sprout.
  • For storage, onions and garlic do best with a humidity of 60%-70%. Refrigerators are usually more humid than ideal. If you have a barn with the right temperatures, that will work better for long-term storage.
  • In our climate, with a long period in the danger zone temperatures, we keep alliums in the warmer storage range in a barn, shed or basement until ambient temperatures drop close to 55ºF, and then move them to a refrigerated cooler at 32°F -41°F (0-5°C) 95-100% humidity.
  • Do not freeze: onions get chill injury at 31°F (-0.5°C)
  • If at all possible, do not store onions with fruits, including squash, as these exude ethylene which promotes sprouting.

More reading

Other southern onion growers might like to read this publication by Dr Joe Masabni of Texas AgriLife Extension, called simply Onion

Walla Walla large non-storage onion.
photo by Southern Exposure Seed Exchange

Collect ramp seeds

If you have been wild-crafting ramps (more on that in March), this is time to pay the piper. Collect seed and scatter it over the patches you dug from. Or collect seed to grow in woodlands at home – without of course, taking too many away from a place they could grow naturally. See the article in Modern Farmer. The seeds scattered in zones 3-7 in early fall, take 6 to 18 months to germinate, and the plants take 5-7 years to grow to harvestable size. Thus it’s easy to see how wild ramps have been seriously over-harvested.

Buy seeds year-round and bulblets in late winter at rampfarm.com and mountaingardensherbs.com.

Read more in Growing and Marketing Ginseng, Goldenseal and Other Woodland Medicinals by W. Scott Person and Jeanine Davis of North Carolina.

Alliums for July: harvest minor alliums, finish harvesting bulb onions, snip and sort garlic and bulb onions.

Siberian garlic.
Photo by Southern Exposure Seed Exchange

Allium planting in July

In Virginia, July is not a big month for planting alliums. If you have perennial leeks or Egyptian onions you could if necessary divide clumps and replant them. But I would postpone doing this if I could and replant dry bulbs in August, or divide newly re-sprouting clumps in September.

Allium harvesting in July

In June I listed dates of our usual allium harvests for that month. Some of the minor allium crops (shallots, leaves of perennial alliums) can be harvested in July, but some, like the tiny, purple shallot-like L’itoi perennial onion (Allium cepa var. aggregatum ) die back in June and are sending up new green shoots by early July, so you’ll have to wait for those to be big enough to harvest. During dormancy you could divide the clumps and replant. Harvests of full-sized bulb onions and cipollini (small bulb onions) continue through July.

Bulb onions

I discovered our bulb onion (A. cepa var. cepa) harvest dates had ranged more widely than the 6/15-6/30 I reported last month. In the years 2008-2012, we harvested bulb onions 6/4–7/26, depending on the variety and the weather. In October I’ll write more about choosing onion varieties for your area.

Bulb onions curing on a rack.
Photo Wren Vile

Curing bulb onions

Some books recommend curing in the outdoor sun. These books are written further north or further south! This doesn’t work in our climate, where we need to provide partial shade, moderate temperatures, and good air flow (and no rain). Further north, temperatures are lower, and onions do not bake during outdoor curing. Further south (in Georgia for instance) onions mature much earlier in the year (they have been growing over the winter). The sun is not yet too intense or the humidity too high, and they can cure onions in the field there.

Handle onions gently – many rots are the result of poor handling post-harvest. Spread in a single layer in a warm dry place, and check every few days. The ideal conditions are 85ºF-90ºF (27ºC-32ºC) with constant air movement, no direct strong sunlight. We use racks in a barn, with fans to keep the air moving.

Trimming, sorting & storing bulb onions

Trimming should begin about two weeks after you hung the onions to cure. Test them by feeling maybe a dozen necks to see if they are ready. Pinch the necks gently just above the bulb, and then rub your thumb and forefinger together. They are ready for trimming if the majority of the necks feel dry and papery. The necks should not feel slippery or moist. If more than one or two still feel damp, but not slippery, wait a couple of days before testing again. Do not wait more than three weeks after harvest to get the onions in storage. The longer you leave the onions hanging, the more rot you will have to deal with.

To trim get a good pair of scissors, and a glove on your scissor hand to prevent blisters. Trim the necks off about ½” (1 cm) from the bulb, and trim all the roots off.

When trimming, sort the onions into three categories. Onions with wet necks or soft spots are for immediate use at home. Bulbs that feel firm and have dry necks are storage bulbs, and should be trimmed and put into mesh bags, which we store lying flat on shelves in our basement. Most onions store reasona­bly well if spread in a layer less than 4″ deep or hung from the ceiling in small mesh bags. Avoid large bags where the weight of the onions will crush the ones at the bottom. Ensure good air circulation.

The third category is for bulbs that aren’t obviously use first, but for some reason might not store for months. Maybe the necks have a spongy feeling, or the skin is split, or the necks slip a little bit. Label these onions “Use Soon,” trim them into mesh bags and put them in the basement like the storage onions.

Onions can be stored at 60ºF-90°F (16ºC-32°C) if they have never been refrigerated. It is important to avoid the 45ºF-55°F (7ºC-13°C) range, because that’s when they sprout. We have limited refrigerated storage, so we keep alliums in the warmer storage range until room temperatures drop into the danger zone, by which time there is space in the cooler. More about onion storage in August.

Onion harvest
Photo by Raddysh Acorn

Here’s information from the Roxbury Farm Harvest Manual (upstate New York) – a quite different story from Virginia:

Storage onions

Pull the onions out of the ground, clean off some damaged leaf parts, taking care not to remove too many of the outer layers. Cut off the tops immediately, 2-4″ (5-10 cm) above the crown.  If for long-term storage, bring the onions to the greenhouse for curing. Cover the greenhouse with 80% shade cloth to protect onions from sunscald.

As soon as the necks are sufficiently dried up (you can no longer roll any stems between your fingers and the stem tissue feels like paper), and the leaves easily crumble off, give them a superficial cleaning, and move the onions into the barn (and not in the cooler due to high moisture levels). Store at 32ºF-41°F (0-5°C) 65-70% humidity.

Green bulb onions, harvest and cleaning

Pull the 3-4″ diameter onions out, before any leaves die, by grabbing the plants as low as possible on the stem to avoid crushing the green stems. Place the onions on the top of the bed all facing the same way. Clean off the outer leaves around the bulb to leave a clean white bulb. Bunch 2-4 onions together with twisties. Cut the excess length off the leaves so the bunch fits lengthwise in the box. Pick up the finished bunches, and place them in the box.

Washing onions would shorten their storage life. Remove most of the dirt in the field. Bunched fresh onions look much nicer when clean. Spray off the onions with a hose but do not dump them into a washing tub. Pack in closed containers for storage longer than a week. Store at 32-41°F (0-5°C), 95-100% humidity.

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Harvest minor alliums

Cipollini (A. cepa var. cepa) will be ready to harvest from spring transplants here in the first half of July, if they weren’t ready in late June. We sow those in plug flats 1/25 and transplant 3/21. Read more about cipollini in the June post. We love Red Marble, which stores really well. Purplette disappointed us – it doesn’t store well.

French Red shallots.
Photo Raddysh Acorn

Shallots (A. cepa var. aggregatum) grown from seed started in late January and transplanted in March will mature here 7/4 -7/30, 4-8 weeks later than those grown from replanted bulbs (planted in October). We started with a packet of seeds, replanting all we grew for several years. We got lots of winter-kill trying to over-winter the bulbs in the ground. To save bulbs for replanting in early spring, refrigerate them. And accept a later harvest than the 6/10 of fall-planted bulbs.

Top-setting onions (aka Egyptian onions, tree onions, walking onions) produce tiny red-purple bulbs in the umbel instead of flowers, maturing in September. They were previously named Allium cepa var. proliferum. According to Wikipedia, they are now known to be a hybrid of A. cepa and A. fistulosum. The larger bulbils can be harvested in July, and used to make mixed pickles.

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Other Allium tasks for July

Trimming garlic stems (blue nail polish optional!).
Photo by Brittany Lewis

Snipping, Sorting and Storing Garlic – see the link to my previous blogpost, where I spelled out these tasks, including setting up, snipping and sorting into three categories for replanting, for storing and for using soon. Garlic can be stored in the same high temperature range as bulb onions, provided it has never dropped into the sprouting temperature range of 40-55°F (5-13°C)

Sort potato onions – see the first step of this process described in my June post and the harvesting described in my May post. We made slatted racks 5′ by 2.5′ (150 x 75 cm) which stack on each other leaving space for air. Curing is important for quality and long-term storage. Space the bulbs loosely on the racks to provide good air circulation. If humidity is high, use fans, dehumidifiers or an air conditioned room, to improve drying. Curing takes 2 to 4 weeks.

I aim to sort through our potato onions once a month, starting a few weeks after harvest.

7/10-7/15: This could be the second sorting for fall-planted potato onions, the first sorting for late winter planted ones. Keep the clusters together, as breaking them apart stimulates sprouting. Wait till the third sorting, in early August, to snip off tops, separate the clusters, sort by size and decide how many to save for replanting. I’ll tell you about that next month.

Remove any rotting onions for immediate use or composting. Start sorting with the largest ones, in case you run out of time. Remove all that are bigger than 2″ (5 cm), bag, weigh, record and label. If you are on a fast track to increase your crop, refrigerate all the large onions at this time, carefully labeled so they don’t get eaten, to plant in September. Refrigerate or plant them, or eat them, the large ones won’t keep long.

Potato onions in early spring, after they have divided into a cluster.
Photo by Kathryn Simmons