I have had several questions recently about storing crops so thought it was time to review storage conditions. The closer you can get to the ideal conditions, the longer the food will keep, but even in less than ideal conditions, much of it can be stored fresh for a reasonable time.
Food that must be kept dry: onions, garlic, winter squash, sweet potatoes. It is ideal if it is cool (10-15oC/50-60oF), too, but dry storage is most important. The problem is that the really cool storage places most of us have, such as crawl spaces, garden sheds, detached garages, etc. are too damp. While it is hard to find a place in a modern home that is cool, it isn't hard to find dry storage. Insulated, dry basements and insulated attached garages can work (as long as there is no gasoline smell to contaminate the food), but you can also store these crops in the house, in a back bedroom or cupboard. I am surprised how many people tell me they store these crops in the guest bedroom, which makes sense since it may only be heated occasionally....
Onions, garlic: Dry storage keeps the skins sealed to hold in moisture and keep out rot organisms. Garlic hanging in artistic braids in the kitchen keeps surprisingly well, but for longer storage, a cooler location helps. No matter what you do, however, some varieties of onions just don't keep for long: 'Walla Walla', red Italian torpedo onions, 'Sweet Spanish' and other sweet onions usually sprout in 2-4 months. On the other hand, good storage varieties, such as 'Sturon', 'Redwing' and 'Ed's Red' shallots, keep for 10 months or more. You can slow the deterioration of sweet onions a bit by keeping them in the refrigerator: they will continue to sprout, but more slowly. Note that the green shoots that sprouts from onion bulbs are perfectly edible. You can also freeze onions (sliced, diced, chopped) if necessary to salvage onions.
Winter squash, sweet potatoes: The vegetables should have been cured well first, holding them in very warm, dry conditions (but not in direct sun) for a few weeks to harden up the skin. Dry storage is more important than cool--in fact, I line my squashes up all along the top of the kitchen cupboards and very rarely see a spoiled spot. Acorn and banana varieties only keep for a 2 or 3 months, while 'Delicata', 'Festival' and some others can keep for a year. Most varieties fall somewhere in between, with a 5-6 month storage period. Just check them regularly for soft or discoloured spots on skin. If you catch it early, just can just cut off the bad spot and bake or steam the squash to salvage the rest. Cooked squash freezes well.
Food that needs to be kept in cool/cold, high humidity conditions: potatoes, apple, pears, kiwi. They do fine in damp outbuildings or crawlspaces (as long as rodents can't get at them), but can be kept in dry, cool locations if you put them in plastic bags or boxes to keep in the moisture. There should still be some air exchange so loosely close plastic bags or punch a few small holes in them; leave the lids plastic boxes loose.
Potatoes: Potatoes must be stored in the dark as well as in high humidity, cool (but not cold) conditions. These are usually the hardest crop to store in a modern home because we don't have that earthen farm basement that kept spuds so well. Refrigerators are too cold for potatoes, causing the starches to change to sugars so the flavour and texture gets weird. For a few months after harvest potato don't sprouts even if they not kept cool, but by spring, it seems they sprout no matter how good the storage conditions. Keep the potatoes in brown paper bags in a damp crawlspace or outbuilding. Indoors, they can be kept in humid in opaque plastic totes with a little bit of air circulation (small holes punches in the sides or lid).
Apples, winter pears, kiwi: These keep best at 2-5oC (35-40oF), which is refrigerator range. In fact, pears apparently are best stored just above the freezing point so I shove them to the very back, bottom of the fridge where it is a little colder. Some gardeners keep an extra fridge for fruit storage and unplug it when it isn't needed. As with all of these crops, how long the fruit keeps depends on the variety. I have held Spartan apples for 12 months in excellent condition in plastic bags in a humidity drawer in a refrigerator, whereas even the best storage facilities can't keep a summer apple, such as Yellow Transparent, in good condition for more than a few weeks. Winter pears don't keep as long as apples: they pretty much all ripen in the refrigerator by January no matter how cold they are kept, but if you still have too many to eat then, they also freeze well (poach them in water or juice first).
Late blight alert: Tomatoes around the region are collapsing from late blight. Few of you still have tomatoes and many of you are groaning about the huge harvest this year so aren't too worried about what's left in the garden. BUT it is always best if you don't get late blight established in your garden in case it overwinters. Before late blight reaches you, get the tomato plants off to the compost pile and pick any fruit you want to keep indoors to ripen off the vine. Note that late blight overwinters on volunteer potatoes left in the garden. Once a plant is infected, the fruit rots quickly so you won't have time to salvage any if you wait until vines are infected.
Staking for Winter: Along with all the leaves or other mulches you are spreading on the soil to tuck up your winter vegetables for winter, be sure to stake up tall, top-heavy plants. The main ones to worry about are the cabbage family crops, which can be broken or uprooted by high winds (and we are bracing for strong wind storms this winter as part of the El Nino weather pattern). Use your tomato cages or drive in 3 or 4 stakes or sticks around the stems of each plant to support them. If their necks get broken or their roots are tipped out of the ground you lose the crop, but if leaves blow off, that's no problem: they just grow more in the spring.
Year Round Harvest Course: There is still space for more participants in my 2016 course at the Horticulture Centre of the Pacific, Victoria. There is one class a month on a Sunday afternoon from January to October; topics include feeding and preparing soil, year round planting schedules, how to grow a variety of vegetables and fruit, preserving, dealing with weird weather, seed saving and managing pests and diseases. For the 2016 schedule of dates and topics, see: http://hcp.ca/events-functions/year-round-harvest/ Contact HCP directly to register.
About Linda A. Gilkeson, Ph.D.
Linda earned a Ph.D. in Entomology from McGill University in 1986, then moved to British Columbia to work for Applied Bio-Nomics Ltd., a company that produces biological controls. From 1991 to 2002 she worked for the provincial government, promoting programs to reduce and eliminate pesticide use. She was head of the provincial State of Environment Reporting Unit for the next six years, then the Executive Director of the Salt Spring Island Conservancy until the end of 2011. Linda now devotes her time to writing, teaching and consulting.
Linda has co-authored pest management training manuals for the government and organic gardening books for Rodale Press. She has self-published two books: Year Around Harvest: Winter Gardening on the Coast and West Coast Gardening: Natural Insect, Weed and Disease Control. Her recent book, Backyard Bounty: The Complete Guide to year-Round Organic Gardening in the Pacific Northwest, has become a BC best seller.
As a private consultant, Linda is a regular instructor in the Master Gardener programs in BC and is busy year around giving workshops on pest management and organic gardening.
Linda has served as President of the Entomological Society of Canada, the Professional Pest Management Association of BC, the Entomological Society of BC and the Salt Spring Island Garden Club. She was awarded a Queen’s Jubilee medal in 2003 and an outstanding achievement award from the Professional Pest Management Association of BC in 2005.
Follow Linda's work at lindagilkeson.com