6 Top Tips for Growing Garlic

29 September 2016, written by Barbara Pleasant

Winter is coming, so it’s time to get busy growing garlic. Easy to grow and simple to store, garlic produces best when you make the most of its natural talents, summarised here in six timely tips.

1. Plant garlic in autumn.

Autumn-to-spring is the best season for growing garlic. Just like tulips, garlic cloves planted in fall quickly develop roots, so the little plants are well established by the time cold weather stops their growth. Then they start growing again as soon as the soil warms in early spring, and produce a harvestable crop by the middle of summer. Cloves also can be planted first thing in spring, but yields of spring-planted garlic can be half of that from cloves planted in the autumn, and they mature later, too. Why not do it right? Garlic repels vampires, which come out on Halloween, so it’s easy to remember that the garlic growing year starts before the end of October.

2. Plant two or more different garlic varieties.

Part of the fun of growing garlic is trying new varieties, and I like to try one new-to-me variety every year. At the same time, I have been growing ‘Music’ for almost ten years, which deserves its popularity for size and vigour. The main thing is to diversify, so that if one variety has trouble, another can take up the slack.

University-based field trials in the US provide a solid list of worthy garlic varieties. In a Kentucky field trial, two large hardnecks, ‘Music’ and ‘Bogatyr’, produced the largest, prettiest bulbs, with ‘Polish Softneck’ the leader among softneck types. ‘Music’ and ‘Polish Softneck’ also have done well in trials in chillier Michigan, along with ‘German White’, which tastes spicier than ‘Music’ and produces large bulbs. A 2013 trial in Rhode Island evaluated a different list of garlic varieties, of which ‘Chesnock Red’ was the top hardneck, with ‘Oregon Blue’ heading the list of softnecks.

While this is a nice list of garlic varieties for many gardeners, bigger is not always better when you are growing garlic to store through winter and well into spring. In my experience, small and medium-size bulbs store better than big ones, so I try to keep a few petite varieties in my collection. For example, the bulbs of softneck ‘Blossom’ are quite small, but they mature early and keep for 10 months – two traits that keep them on my planting list year after year.

3. Plant large single cloves.

Large cloves provide abundant food reserves for growing garlic seedlings, so the large outer cloves are the best ones for planting. But there is a catch. Often very large cloves are on the verge of dividing into two, and once planted the double cloves grow into tightly spaced twin plants that produce lopsided bulbs. Be choosy when deciding which cloves to plant, and bypass little cloves as well as big doubles.

4. Mulch through winter.

Garlic competes poorly with weeds, and several studies have shown that mulching garlic through winter with straw or coarsely chopped leaves leads to bigger and better yields. Winter mulch helps keep nutrients in the soil from leaching away, and also can help buffer little plants from strong winds. My favourite garlic mulch consists of coarsely chopped leaves collected with the season’s last grass clippings mixed in. The thread-like grass clippings help hold the leaves in place, which form a resilient cushion for heavy loads of ice or snow.

5. Prepare for pests and diseases.

Many gardeners have no problems with pests when growing garlic, but two serious issues can sabotage crops. Onion white rot can be a persistent soil-borne disease, and onion root fly larvae can appear out of nowhere.

Solarisation is emerging as an effective tool for rehabilitating soil that hosts the white rot fungi, a common soil-borne disease that causes garlic and onions to turn yellow and rot into a mushy mess. To solarise soil, you mix in some organic matter such as grass clippings, dampen the amended soil well, and then cover the plot with clear plastic, tucked under along the edges, for six weeks during the warmest part of summer. The plastic raises soil temperatures enough to cause the fungi to die or become dormant. Expect survivors as the soil temperature returns to normal, which can be dealt with using the “bait and switch” method described by Ann Marie Hendry in her recent story, How to Control Onion White Rot. Short version: you use garlic powder to trick the fungus into thinking a host plant has arrived, which turns out to be a hoax and the fungus dies. Then you do it again, because the white rot fungus does not go down easily!

Onion root fly larvae are a worldwide pest of onions and garlic. Tiny beige worms found feeding in garlic bulbs are the larvae of a small fly, Delia antiqua. Three generations per summer is not uncommon in temperate climates, and some years are much worse than others. I can’t tell one fly from another, but this Canadian study revealed useful details for monitoring onion fly activity. White sticky traps are preferred over other colours, and prime flight time is 6 to 8 in the evening. When I catch several suspects in my garlic patch in early summer, I install a barrier of fleece or fine mesh to prevent further damage.

6. Cure Dry and Dirty.

The question often arises as to whether it is harmful to wash off garlic bulbs after they are harvested. Turns out, it’s a bad idea. This interesting study of curing procedures at farms in New York revealed that washed bulbs usually discolour in storage. But it is safe to trim off roots and green leaves soon after harvest, which may hasten the drying process.

As with other gardening endeavours, your luck growing garlic will improve with experience. The best time to get started is right now.