How to Store Your Summer’s Harvest of Potatoes and Onions
During the winter months, when the ground is covered by a thick blanket of snow, there’s something particularly satisfying about still being able to eat food from your garden. Many summer-grown crops including potatoes, onions, garlic, beets, carrots and winter squash, can be stored with relative ease to nourish you right through until the next growing season. Even a modest-size garden can yield a substantial crop of winter keepers.
To be successful storing these keeper crops at home, here are a couple factors to keep in mind:
Some varieties store better than others, so be sure to seek out the ones that are known to be good keepers.
Crops that are harvested at their prime – not before or after – store best. Time your plantings so they mature at the close of the season.
Only first quality, unblemished produce is suitable for storage.
Optimum temperature and humidity for storage varies by crop, so be sure that the crops you plan to store match the storage conditions you can provide.
There are so many wonderful kinds and colors of potatoes to choose from: fingerlings, bakers, boilers, white, yellow, pink, red, and even blue or purple. All are delicious eaten fresh from the garden, but if you want to store some potatoes for eating in the late fall and winter months, you’ll need to plant varieties that are well-suited to storage as well as to your growing area. Readily available potato varieties known to be excellent keepers include Katahdin, Kennebec, Yellow Finn and Yukon Gold.
Potatoes can be grown in a standard garden row, in a raised bed or in a container such as a Potato Grow Bag. The more foliage your plants have, the more good-sized tubers you’ll harvest, so it’s important to keep your plants as healthy as possible.
In late summer when the potato foliage has died back, your potatoes can be dug and “cured” for storage. Curing toughens up a potato’s skin and extends its storage life. Cure the tubers by laying them out on newspaper in a well-ventilated place that’s cool (50 to 60 degrees F.) and dark (so they don’t turn green). After about two weeks, the skins will have toughened up. Rub off any large clumps of dirt (potatoes should never be washed before storage) and cull any damaged tubers, which should be eaten, not stored. Treat the tubers very gently so as not to bruise or cut them. Nestle your spuds into ventilated bins, bushel baskets, a Root Storage Bin or a cardboard box with perforated sides. Completely cover the boxes or baskets with newspaper or cardboard to eliminate any light. Even a little light will cause potatoes to turn green and be rendered inedible. The ideal storage temperature for potatoes is 35 to 40 degrees, though they will usually keep for several months at 45 to 50 degrees.
Wet summers are bad for picnics but great for onions. The more moisture onions get, the larger they grow. Onions also benefit from lots of sun, and will sulk if they’re crowded by neighboring plants or weeds.
Consider starting your onions from seed or young plants, as growing from seed allows you choose a variety that’s known for long storage. Strong-flavored, pungent onions store best (the same chemicals that make onions pungent make them good keepers). There are both red and yellow storage onions; those extra-large, milder onions should be eaten fresh as they don’t store well.
Onion seeds must be started indoors, several months before they’re planted into the garden. Broadcast the seeds so they are about 1/2″ apart and cover lightly with soil. Once the plants are up and the stems have straightened, trim the tops with scissors to a height of about 2″. Repeat every couple weeks (sort of like trimming a Chia pet) until it’s time for your onion plants to go into the garden. These haircuts force energy into the roots and also keep the plants from toppling over. Onions are heavy feeders, so be sure to amend the soil in the planting area with compost and a granular organic fertilizer. Set the seedlings (which may be less than 1/8″ in diameter at the base) about 6″ apart in each direction. Keep them well-watered and well-weeded, and make sure they don’t get shaded by neighboring plants.
In late summer, the leaves of onion plants flop over. This signals that it’s time for the plants to stop growing and start preparing for winter. Allow the plants to remain where they are until the necks begin to tighten and the foliage yellows. If the weather is dry and there’s no danger of frost, onions can be harvested and laid right on top of the soil to dry for a week or two. If the weather is wet or frost is possible, harvest your onions and move them immediately into a protected location where they will stay dry. The floor of the garage or a covered porch works well. Spread the onions out in a single layer and let them “cure” for two weeks. During this time the necks will wither and turn brown, and the papery skins will tighten around the bulbs. Once the necks have dried and there’s no more moisture in the stem or leaves, you can bring your onions indoors and store them in mesh bags or bushel baskets. Keep them cool (35 to 45 degrees F.) and away from light. Another technique for storing an abundance of onions: make caramelized onions.
Let’s Go Garden!