Allium Allies; planting, growing, and curing alliums. How to grow onions and garlic.

Almost every meal we cook begins with an allium. The allium family includes such beloved friends as onion, garlic, chives, and more. Sautéed onions, minced garlic; these are the heart of so many cuisines. While they may never have the curb appeal of that first red tomato, they are a valued addition to the winter garden. Plant onion and garlic sets now, after the heat of summer has passed. They take up little space, need minimal care, and grow all through the cold season to be harvested in time to make room for the summer crops. While they take a long time to mature, they are a valuable placeholder in the winter garden, and will reward your patience richly.


Onions, garlic, and elephant garlic can be planted either as sets or starts. Starts are grown from seed, and come in the familiar 6-packs in the veggie nursery. They tend to be seeded densely, and must be carefully separated from the soil, one by one, and their roots untangled before planting, to allow room for the bulb to form. Starts are best planted a little earlier in the year; now is a better time to plant sets.

Sets are small bulbs that are already a little further along in their development. Now, in late fall/early winter, is the time to plant garlic and onions in sets for a late spring harvest. There’s something deeply satisfying about handling these pearl-sized onions, somewhere between giant seeds and tiny onions. The garlic comes in cloves, just like you get at the grocery store, which must be separated into individual cloves. We carry varieties that have been specifically selected to grow well in tis climate and season, and which have been certified disease free.

The cold winter sun will nourish the sets as they grow; even though alliums thrive in the cold, they do need sun as well. Wait until the autumn heat waves have passed, as intense heat at the beginning will cause them to bolt, or flower before making the bulb that we like to eat. Give them fertile soil, with a pH of about 6-6.8, and amend with enough organic material to make it light and fluffy; you want the growing bulbs to expand easily into the soil, and not have to strain to force their way through hard, compacted soil. We like to turn over the soil before planting, and work a bit of compost and organic fertilizer into the soil as we do so. This creates better results than placing fertilizer in more concentrated amounts at the base of each set, allowing for slow release of nutrients over the growing season. When we have it, we like to use our own homemade compost. When we want a little extra boost, we like both the Soil Conditioner and the Farmyard Blend from Gardener and Bloom, which we carry in bags. The Soil Conditioner adds great texture that takes a while to break down, so it creates room in the soil that makes it easy for large bulbs to form. The Farmyard Blend is a little finer, and also has more nutrients from animal manures; make sure you blend it into the existing garden soil well, so that the larger amount of nitrogen doesn’t burn the young plants. After working the fertilizer and amendments in, we water the seedbed well and deeply. Sometimes, after disrupting the soil structure as we turn it over, we need to water it a few times, or water it low and slow with a few hours of drip irrigation, to ensure that the moisture is evenly distributed throughout the soil. Planting into moist soil is so good for all plants, but especially important for sets. The dormant bulbs will be awakened by the moisture, to wake up to start growing.

Plant each set or garlic clove about 1 1/2” deep, and about 6 inches apart. Imagine a fully formed onion or garlic beneath the soil when mature, and allow for a couple inches of space between the mature bulbs. Because young sprouts can resemble grass, this is a good crop to plant in neat rows, so that it is easy to determine what is a desired allium and what is a pesky grass seedling. One method that works well is to dig a shallow row trench, with a bit of fluffy compost layered at the bottom. Nestle each set or clove into the trench, pointing upwards. Both garlic and onions have a slightly pointed tip at the top that indicates which way they should be planted. There is a small, dry, calloused butt at the bottom of each bulb that the roots will grow from, and the pointed tip will sprout green blades to push up through the soil. Cover over the bulbs in the trench, and mark each end with bamboo stakes or other garden markers. Interplant with radish seed, if desired, to maximize the use of space. The fast growing radishes will mark the rows of young onions and garlic, and can be harvested in only a few weeks, leaving room for the alliums to expand and grow.

Keep the onions and garlic well watered throughout the winter; they do not need to be soggy, and the rain can do a lot of the work for us here, but it is important to make sure that they stay consistently moist, especially in the first month as the get established. Onions and garlic have shallow roots, so we need to bring the water to them. Water whenever the top inch of soil becomes dry. The less water they receive, the spicier and smaller they will be, although the variety you choose will also affect size and flavor. A light mulch on the top of the soil is helpful, but make sure it is not too deep or heavy. Onions and garlic both can be susceptible to rot if they are buried too deeply. The neck of the plant is a vulnerable spot that needs access to air circulation.

Come spring, the bulbs will be fully formed. Garlic will usually begin to die back to indicate when it is ripe. Harvest in the late spring when the outer 2 or 3 layers of leaves have begun to brown. If you wait longer, all of the leaves will die back, which means fewer protective layers around the cloves. These layers help the garlic cloves to stay fresh in storage. Onion tops will also begin to yellow and fall over to indicate ripeness, and you should see the tops of the bulbs sticking out of the soil. Pull them up, and shake off the dirt, but do not wash them at first. Allow the soil on them to dry, so it can be shaken off more easily. Garlic and onions both need to go through a curing process, where they are laid out to dry in a warm spot with good air circulation. During the curing process, the roots (not the bulb, but the roots attached to it) will shrivel, and the neck above the bulbs will slowly dry, sealing off the juicy bulb from spoilage organisms. After 7-10 days of cure, the garlic and onions will be ready to store for the longer term. Clip off the dry plant material, and roots, and rub off any remaining dirt, leaving the papery outer skin intact. Now a cool, dry, dark place will help them stay fresh for longest. I like a covered basket in the pantry for storage.

Over to You

It’s part of our mission here at Mountain Feed to help you grow beautiful, sustainable, gardens whether you have sprawling acres of farm or just a tiny plot along the highway. Stop by and say hello on FacebookTwitterInstagram or Pinterest. Or, as always, you can do it the old-fashioned way and come by the store to speak with one of our in-house experts.

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