Grow garlic in your backyard

By: Trish Grenfell
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“Once you taste home-grown garlic, you won’t be satisfied with supermarket varieties,” said “Fine Gardening” editor Ruth Lively. A famous seed catalog currently sells 30 types of garlic; you don’t see that while grocery shopping. This fall I may become a garlic farmer.

You don’t need a large space to generate a large yield and now is the perfect time to prepare to grow garlic (allium sativum). The only requirements are a well-drained soil, full sun, adequate moisture, and knowing when to plant and harvest. And weed elimination is vital since they will easily overtake young garlic plants.

Garlic is grown from cloves using large, disease-free bulbs purchased from a certified nursery near you or online. Don’t plant grocery store garlic cloves; they may carry diseases or nematodes and are usually sprayed to prevent sprouting. Buy large bulbs which are more likely to produce large bulbs. And if you want to grow garlic again next year, save your best, largest bulbs as “seeds.” Buy your bulbs this year as soon as they become available in the summer (they sell out) but don’t “crack” them until the day you plant. Individual cloves won’t keep long due to disease susceptibility and dehydration.

Two subspecies of garlic are commonly grown here: Allium sativum var. ophioscorodon  (hardneck garlic) and a. sativum var. sativum (softneck garlic). Hardneck types produce flower stalks called scapes which are good to eat but are removed by most gardeners to concentrate growth on the bulbs. Hardnecks won’t store as long as softneck types but their flavor is more robust. The many hardneck varieties, each with their own unique flavor, are often hot and/or spicy. Examples include: rocambole, porcelain, purple stripe, Asiatic, turban and many more.  The adventure is in growing many varieties.

The softneck subspecies with its milder flavor dominates commercial production and it stores better. The two most popular commercial softneck varieties are “California early” and “California late.” According to the Western IPM Center (Davis), fresh market growers prefer the late despite its one month longer growing period. There are several subtypes of late and early; artichoke is a common early, silverskin a popular late. (Note: elephant garlic tastes like a very mild garlic but is really a leek.)

Prepare soil now by adding compost, hopefully it includes well-rotted manure and micronutrients. Note: when it is planting time and soil is still not prepared, you can lay the compost on the planted cloves and cover with mulch. Soil is best if pH is slightly acid (between 6 and 7), but garlic will grow in a wide range of soil pH. Don’t add lime unless your soil pH is less than 5.8. There is no need to add phosphorus fertilizer unless a soil test indicates it is necessary. Since garlic is a moderate- to high-nitrogen user, some horticulturists like to add nitrogen fertilizer at this point. Others wait until shoots appear above ground in spring. Fertilizers used include:  alfalfa, blood or fish meals — or synthetic sourced nitrogen. Do not apply nitrogen during the last 60 days before harvest.

Cloves should be planted early enough in the fall to allow a good root system to develop before the cold forces winter dormancy (the longer you wait, the smaller your garlic), but late enough to prevent shoot emergence prior to freezing temps. In recent years warm temperatures have often delayed planting; it’s now usually October instead of September in the Auburn Area. Plant earlier at higher elevations since temps drop faster there in the fall. Because we can’t fully anticipate the weather, garlic sprouts often emerge a few inches above the soil prior to cold weather, but don’t worry. Unless it gets extremely cold quickly, little damage will result. Applying two to four inches of mulch at planting can reduce this damage and will also help preserve moisture and prevent most weeds. If you miss the fall, early spring planting is OK, but much smaller bulbs will result.

Plant the cloves pointed side up. Do not peel off the papery covering. Discard the small cloves and plant the larger ones one half to three inches below the soil surface. The colder the winter, the deeper the cloves should be planted. UC Davis recommends planting one half to two inches deep in its region. Those living at higher elevations of the Sierra might need to plant three inches deep. Leave a minimum of four to six inches in all directions between clove plantings; if space is not a problem, increase the separation. Garlic prefers high soil moisture levels, but not soggy. As mid-June approaches, taper off on the watering.
Insects are not a major problem in the non-coastal areas of California. Risk of disease is minimized if the soil truly drains well, the “seeds” are disease free, weeds are managed, bulbs aren’t damaged, and the planting area has not been used to grow members of the onion family in the last four years. 

Fall plantings take about eight months to mature. Harvesting too early results in smaller bulbs, too late will cause cloves to pop out of their bulbs. Some horticulturists tell us to harvest when one-third of the plant leaves turn yellow or brown. Others say to always take up a few bulbs in late June (even if all leaves are green) and cut them in half. If the cloves fill the skins, the crop is ready to harvest.  
Pulling bulbs out of the ground may crack them, reducing shelf life. Instead use a garden fork to ease them out. Keep the shoots and bulbs attached. Carefully knock off excessive soil and then leave them to cure in a warm, dry, airy place (not direct sun), for three to four weeks.

Then you can enjoy your harvest. You may never again buy garlic at the supermarket.

Trish Grenfell is a Placer County master gardener. Contact Placer County gardeners at 530-889-7388 or