harvesting potato onions – Sustainable Market Farming

Alliums for June: planting leeks, harvesting garlic and bulb onions

Dibbling holes for planting leeks.
Photo Wren Vile

This month is a big harvest time for alliums, and it’s also leek planting time in Virginia.

Transplanting leeks

We do this job in early June. I have written about leek planting in 2015 and in 2014 (from flats), and from a nursery seedbed in 2013 . Initially we liked the nursery seedbed method of growing transplants because it freed up space in our greenhouse and coldframes for the crops that really needed protection from the cold, which leeks really don’t. But leek seedlings are skinny, and easily lost to weeds, which we had a lot of in some beds. While planning to really clean up our act with the weed seed-banks in the beds (and plan to use only the cleanest bed for our leek nursery), we tried sowing in flats, and that’s the method we now use. We put the flats directly in the coldframes – we still save the greenhouse space. We found we got better seedling survival in the flats, so we didn’t need to plant as many as we did with the old method. We were able to cut back to 50% of what we had planted. Also the seedlings grew faster and we have been able to transplant 2-3 weeks earlier than with our outdoor seedbed method, from the same sowing dates.

Leek seedlings in flats in April.
Photo Pam Dawling

We also learned that weeding leeks is really, really important, and that it can be worthwhile to side-dress leeks part-way through their very long growing season. We made the mistake one year of letting weeds get big before we pulled them up (it was a wet year, not conducive to successful hoeing). We got miserable leeks that year, not just from the smothering effect of the weeds, but we now think that the weeds removed a lot of the soil fertility. We decided to plant fewer leeks and focus on taking better care of them! That has paid off.

Garlic harvest underway.
Photo Marilyn Rayne Squier

Allium harvests in June

We are still happily harvesting scallions (see Alliums for May)

Our June allium harvests have generally occurred in this order:

5/31–6/14 hardneck garlic,

6/10–6/25 Spring-planted potato onions. By “spring”, I mean Jan-late Feb here.

6/11–6/18 Softneck garlic

6/15–6/30 bulb onions. See the SESE Onion Growing Guide for more info:

“When most of the tops have fallen over, pull onions, cure in partial shade for 2-3 weeks until necks have thoroughly dried. Clip tops to within 1″ of the bulb. Breaking over the tops by hand to accelerate harvest harms the keeping quality of some varieties and helps the keeping quality of other varieties.”

Elephant garlic will also be ready in June, but we stopped growing it when so much winter-killed that we harvested less than we’d planted! Elephant garlic is botanically a leek (A. ampeloprasum var. ampeloprasum).

The small Cipollini bulbs (aka cocktail onions, boiling onions, pickling onions) may also mature this month. The larger ones can be used as fresh bunching onions. All may be cured. Some of those store well (Red Marble for instance). Others such as the flat Gold Coin do not at our latitude, as the necks don’t dry tight, so those should be used soon or pickled. Cipollini naturally have more sugar than most onions, which makes them ideal for caramelizing in butter or oil or roasting whole.

Hanging garlic in netting to cure.
Photo Nina Gentle

Harvesting garlic

As I noted last month, hot weather above 91°F (33°C) ends bulb growth and starts the drying down process. I wrote Garlic Harvest step by Step and Drying and Curing Garlic Step by Step here in 2016, along with some ponderings about whether a ground floor shed or an upstairs barn offers the better airflow, and whether better airflow is worth hauling all the garlic upstairs and down again. We didn’t come to a conclusion, but we didn’t find time to build our new barn. So once again, we are hauling the garlic upstairs to cure and down again after it’s trimmed and sorted next month.

Hopefully you will have removed any mulch when you got the scape-appearing signal, and the soil will have had a chance to dry to a workable level. We were doing quite well until we got 3.5″ of rain in one day. Now it’s all much wetter than ideal.

Hang your garlic to cure for 3-6 weeks or even longer, with fans if the humidity is high. Don’t set the fans too close to the garlic, your goal is to improve the air flow, not blast the bulbs and shrivel them up. I’ll come back to the question of how to tell when the garlic is cured and what to do then next month. If your garlic is ahead of ours, see my book Sustainable Market Farming, and know that the key is dry necks.

Garlic bulb cut horizontally to check maturity (good now or soon).
Photo Wren Vile

Signs of garlic maturity

If you live in a cooler climate than us, you might be puzzling over when to harvest your garlic. Margaret Roach in the Hudson Valley, New York, has a great article on determining garlic maturity on her blog A Way to Garden. Harvest there happens 7–8 weeks after ours. Margaret has a good collection of articles on growing, harvesting and curing garlic.

Watch the color of your garlic patch for a general “fading” and also count how many fully green inner leaves there are on a dozen random sample plants. Green leaves represent intact “wrappers” on the bulb, and having at least 4 will help your bulbs store well. Six is better, five is enough, if your garlic doesn’t have to travel to distant markets. If you wait too long, the wrappers will rot in the soil.

Another sign of maturity that we use with our hardneck garlic is to dig a few sample bulbs, and cut them in half horizontally. If there are small air spaces open between the remains of the stem and the cloves, the bulbs are ready. If the cloves have not even differentiated, and you are viewing a single mass of garlic, you are too early by quite a bit. Test once a week. If your cloves are already springing apart from each other, you are late. Your delicious garlic will not store for long. You might need to mince and freeze it in ice cube trays, if you want to preserve some for a while.

Softneck garlic

We grow Polish White. Softneck garlics tend to store for longer than hardnecks, so we always save ours till we’ve eaten the hardneck garlic. The big reason we don’t grow only or mostly softneck garlic is that the bulbs have lots of tiny cloves in the center, and these are tedious to peel, when you are cooking for a hundred. According to Ira Wallace at Southern Exposure Seed Exchange, most hardnecks store 4-6 months, although Music and Chesnok Red can keep 7 months or more in central Virginia. Softnecks such as Italian Softneck, Inchelium Red and Silverskins can store for up to 12 months under good conditions.

Potato onions.
Photo Southern Exposure Seed Exchange

Harvesting spring-planted potato onions

The harvesting process is the same as for fall-planted potato onions. Lift them gently when the tops have died down, and put them to cure on racks with fans. If any of your spring-planted bulbs have produced bulbs larger than 2.5″ (about 6 cm), go ahead and eat those, or refrigerate them till September and replant. Those giants do not store well.

Sorting potato onions

Potato onions need sorting about once a month to remove any that are rotting. If it is already a month since you harvested your fall-planted multipliers, do the first sorting now. Timely sorting will minimize waste, because you will stop rot spreading. And you might get to some that are still “good in parts”.

Onion bed in late April.
Photo Kathryn Simmons

Harvesting bulb onions

There are many different onion varieties and the ones for your area will depend on your latitude. I wrote about this in my book Sustainable Market Farming, and for now, I’ll skip that complex issue. I’ll come back to it in the fall. Assuming you have grown some bulb onions, it’s now time to harvest, as they mature.

If the varieties you grew are not storing types, simply pull them up when you want to eat them, or when the tops fall over. Most kinds will keep for a few weeks, but some not much longer than that. Be realistic! If you have lots of non-storing ones, you can sell, trade or give them away. Or you can chop and freeze them. Or use them in salsa.

The tops of the onions start flopping over here in mid- to late-June; this is the sign that they are ready to harvest. It’s best to harvest during drier weather, but sometimes you have to harvest wet just to get them out of the ground. Hot, wet weather is the worst, so it is best not to let the onions sit around in wet soil during very hot days.

Start to harvest a variety when about 50% or more of the tops have flopped over. Gently lift the onions out of the soil—harvest only the onions with floppy tops, leaving the upright onions in the ground to harvest another day. Harvest each bed twice—once to get just the floppy ones, and then the second time to get all the rest.

Storable varieties should be cured on racks for best airflow, until the necks are dry – about two weeks after hanging the onions. Rub the necks between finger and thumb to determine if they are dry and strawy, or still damp. Trim tops and roots of dry bulbs.

No matter what, do not wait more than three weeks after harvest to clear a rack and get the onions in storage. The longer you leave the onions to hang, the more rot you will have to deal with. After three weeks they start to get worse, not better.

Bulb onions curing on a rack.
Photo Wren Vile

Alliums for May: harvesting garlic scapes, scallions and fall-planted potato onions

Pickled garlic scapes, okra and beets.
Photo Bridget Aleshire

This is the first of a new monthly series of blog-posts on Alliums for the Month, which, like my previous series on lettuce and Asian greens, I plan to run for a year. Alliums are the onion family. With this series, I’m going to talk about which alliums to harvest each month, which to plant, and which need other kinds of attention.

Weeding alliums

I haven’t thought of any alliums to plant in May (at least, not here in central Virginia), but there’s plenty to harvest, and don’t forget to weed! Because alliums don’t have big spreading leaves, they are not good at shading out weeds, so we have to take care of the weeds for them! Particularly bulb onions and garlic this month, as they are only a few weeks away from harvest and will benefit from removing weeds and mulch to let in fresh air to help the bulbs dry down (rather than get fungal diseases!)

Harvesting garlic scapes

Starting any day now, we will begin harvesting garlic scapes (the firm, edible flower stems of hardneck garlic). My previous posts about scapes are some of my most popular ones.

See last year’s Garlic scapes, upcoming events, hoophouse seed crops, posted on May 2, 2017. There I noted that in 2017, scapes came early, as did Tulip Poplar flowers, at the end of April. We harvest scapes two or three times a week for about three weeks, until no more appear. Garlic scapes are one of the first outdoor crops of the year, apart from rhubarb and asparagus, and their flavor is refreshingly different from leafy greens (the staple hoophouse crops of early spring) and stored winter roots.

I posted Garlic scapes! Three weeks to bulb harvest on May 11, 2015. That year scapes were later than average. This post is a very popular one, and I’m still wondering if I was over-confident in predicting 3 weeks to bulb harvest everywhere in the US! Please do leave a comment if you have records for how long you get between scapes and garlic bulb harvest.

I’ve done some research into what triggers flowering in garlic, but haven’t found much solid info yet. In general, plant flowering is triggered by some combination of enough vernalization (chilling hours during the winter and early spring – maybe 10 weeks below 40F), plant maturity, temperature and photo-period (the relative length of day and night). In cold weather the plants suppress the flowering signal. The leaves perceive the amount of daylight, and when the temperature is also right, they trigger flowering by sending a signal (called Florigen) to the shoot tips. Florigen may be an actual compound, or may be some combination or ratio of several plant hormones, produced by one or more genes in the plant. Almost all these factors are outside our control, once the plant is in the ground, so the best we can do is pay attention and be ready to act.

There is a bit more information about the triggers for bulb initiation and for drying down. Garlic bulb initiation (and the end of leaf growth) is triggered by daylight increasing above13 hours in length (April 10 here at 38°N). Soil temperatures over 60°F (15.5°C) and air temperatures above 68°F (20°C) are secondary triggers. When I was in Jamaica last May, I researched growing garlic in the tropics, and it may be that temperature is a bigger trigger and daylength is less important in tropical latitudes where daylength does not vary much. Certainly some growers had produced garlic when I didn’t expect it to be possible.

Hot weather above 91°F (33°C) ends bulb growth and starts the drying down process. I don’t yet know how many hours over that temperature the garlic needs before drying down is triggered. We had a few very hot days last week.

It is important to get plenty of good rapid growth before conditions prevent any more growth. Garlic can double in size in its last month of growth, and removing the scapes (the hard central stem) of hardneck garlic can increase the bulb size 25%.

In the 2015 post I described how we pull our garlic scapes, to get the most out–we love this crop! We also appreciate a late-morning task that’s done standing up! In that post I described the value of mulch and when to remove it.

Garlic scapes to cheer us up posted on May 10, 2013 has been reread a lot–whether that’s because readers love garlic scapes, or seek cheering up, I can’t say.

Pulling garlic scapes – the long view.
Photo Wren Vile

Our harvest process

Here’s the short version. Those looking for more detail can go to my 2015 post.

When scapes arrive, plan some late morning or early afternoon time two or three times a week to harvest them.
As soon as the pointed cap of the scape has emerged above the plant center, firmly grasp the stem just below the cap and pull slowly and steadily straight up. The scape pops as it leaves the plant and you have the whole length of the scape, including the tender lower part.
Gather them into buckets, with the scapes upright, so they are easy to bunch or cut up.
Put a little water in the bucket.
They store well in a refrigerator for months if you don’t use them sooner.
In a few days, more scapes will have grown tall enough to pull, and you can have a second chance on any that broke at your earlier attempt.

————————————————————————————————————–

Clumps of scallion transplants in a Speedling flat, ready to transplant earlier in spring.
Photo Pam Dawling

Harvesting scallions

In May our outdoor planted scallions start. For outdoors, we use transplants, started in January and February, and transplanted in March and April. We sow in Speedling plug flats, a small pinch of seed in each cell, and transplant the undivided clump/plug. We can get a lot of scallions in a small space. Around May 10, the first ones are big enough to harvest (just as the hoophouse ones finish up – what planning!)

To harvest, we loosen the soil with a digging fork, then lift out a clump. We shake the plants, keeping them in a cluster, and trim off the roots and the ragged tops. Holding the bunch in one hand, we pass the scallions one at a time to the other hand, pulling off a single outer leaf and giving the base of the plant a wipe with our spare hand. Next we set the scallions in a small bucket in water. When the bucket is full enough, we dunk the scallions up and down, and transfer them to a clean bucket with a small amount of water to keep them fresh.

Scallions planted in bunches, ready-to-harvest.
Photo Pam Dawling

It’s good to develop an efficient method with little scallions or the harvest takes way too long. Deal with scallions in bunches as much as possible (digging up, trimming), rather than one at a time. Pass them from hand to hand when cleaning rather than set them down on the ground and pick them up again one at a time. Set them into water so they are cleaning themselves while you work on the rest. Don’t fuss with them too much – pull off a single outer leaf, not more. Don’t pick at little bits of skin, unless quite gross. If you are going to band them, start out with a bunch of rubber bands around three fingers on the hand that holds the bunches (leaving the forefinger free for tasks demanding dexterity). When you’re ready to band them, use the other hand to pull a rubber band into position.

Roxbury Farm in New York State has a wonderful Harvest Manual. Page 45 on scallions says they harvest 50 bunches an hour, including trimming tops as needed, but not roots. They wash 100 bunches an hour on a bench, in bunches, with a power spray.

————————————————————————————————————–

A potato onion plant in early spring, showing the cluster that has developed.
Photo Kathryn Simmons

Harvesting fall-planted potato onions

Potato onions (Allium cepa var. aggregatum) are a type of hardy, perennial multiplier onion–once you have them you are self-sufficient. You don’t need to buy seed each year, but select the best bulbs from the ones you grew to replant for the next crop. Also known as Hill Onions, Mother Onions and Pregnant Onions, they produce a cluster of tasty (but not too pungent) bulbs from a single planted bulb, or a large bulb from a small one.

Potato onions have good drought resistance, pink root resistance, onion fly resistance and are widely adapted for different growing regions (not Florida or southern Texas). When properly planted they can withstand sub-freezing temperatures in every area of the continental U.S.

You can order potato onions from Southern Exposure Seed Exchange and other suppliers to be shipped in the fall. See SESE’s Perennial Onion Growing Guide and Garlic and Perennial Onion Growing Guide for growing information.

Yellow potato onions.
Photo Southern Exposure Seed Exchange

The potato onions which were planted earliest (September for us) will be ready to harvest first, at the end of May or early in June in our central Virginia climate. Once you see the tops start to fall over, stop watering the onions and let them dry down.

Potato onions are ready to harvest when the tops die. Not all will be ready the same day. Because onions easily get sunscald if left exposed after they are mature, it’s best to harvest the mature ones every few days. Don’t break over the tops in hopes of a single harvest–it really reduces the storage life. The potato onions sit on the surface and are easily picked up without tools. Handle them gently, to prevent bruising and scratching. Put them into crates or buckets, without pulling off any leaves.

The September planted potato onions were the largest bulbs when planted, and they will usually have divided and produced clusters of small onions. Do not break up the clusters as you harvest, because this triggers sprouting. Set the clusters in a barn or shed, on an airy bench or horizontal rack. The tops break easily, so you cannot hang them as you might hang garlic. Potato onions need good ventilation: we use box fans continuously.

If you find any bulbs larger than 2.5″ (about 6 cm), go ahead and eat those. The giants do not store well. Alternatively, refrigerate them till September and replant. The small and medium-sized bulbs keep 8-12 months under good conditions, and are the best to replant to grow more onions.

Potato onions need sorting about once a month to remove any that are rotting. We plant our large ones in September or early October, our medium-sized ones in late November and our small ones in late January. I’ll tell you more about those when the time comes.