Garlic is one of the few vegetables that should be planted in autumn, and especially if you want to supersize your bulbs. It’s an easy crop to grow and can be planted in in-ground gardens as well as raised beds and even containers. Plus, if you grow hardneck varieties, you’ll enjoy a double harvest of edible scapes as well as the flavourful bulbs. 

For vigorous garlic plants and the biggest bulbs follow these 4 tips:

1) Plant garlic at the right time

Getting garlic cloves in the ground at the right time is key to bulb formation. You don’t want to plant too early or too late. When you plant the cloves earlier than you should, they sprout and start to grow above the ground. When the weather turns cold, this premature growth can be damaged, impacting bulb size. On the other hand, planting very late in the season doesn’t give the cloves time to establish a root system before winter. 

The best time to plant garlic is 4 to 6 weeks before the ground freezes. For me that’s in late October, but you can plant into November in many regions as well. 

2) Prepare the site before planting garlic

Putting a little preparation into your garden bed before you plant your garlic pays off. The biggest garlic bulbs are grown in a sunny garden bed with rich, organic soil that is well-draining, ideally a sandy loam. It should be free draining after rain or irrigation, but have enough organic matter to ensure good fertility. That said, many of us don’t have ideal garden soil and garlic is pretty forgiving of different soil types.

But you can improve less-than-ideal soil like clay-based soils by amending your garden beds with 2 to 3 inches of compost or rotted manure and an application of a slow release organic vegetable fertilizer. The best soil pH for growing garlic is between 6.0 and 7.0. If you’re not sure of your soil pH, or general soil fertility, test your soil a few months before planting so you can make any necessary adjustments. 

3) Plant garlic at the right depth and spacing

Plant garlic cloves pointy side up in rows or a grid pattern, placing the cloves 6 inches apart and rows 10 to 12 inches apart. Overcrowding the cloves results in smaller bulbs and planting them too far apart wastes valuable garden space. As for planting depth, push each clove into the prepared bed so that the bottom is planted 2 to 3 inches deep. There should be 1 to 2 inches of soil above the top of the clove. 

Don’t plant too deep as the plant will use a lot of energy to break through the soil and that can affect mature bulb size. It’s also not a good idea to plant garlic cloves shallowly as these may be heaved out of the ground during winter and be damaged by cold temperatures. Once the garlic cloves are planted, water the garden bed. I like to use a long-handled watering wand to direct water right to the soil surface.

4) Mulch garlic for winter protection

The last step when planting garlic in autumn is mulching. This provides several benefits including insulating the cloves, holding soil moisture, and reducing weed growth. You can mulch right after planting or wait a few weeks until the temperatures are consistently cold. I mulch with straw or shredded leaves, applying a loose 3 to 6 inch layer on top of the bed. 

Don’t wait until spring to plant your garlic, get the cloves in the ground this autumn for the biggest possible bulbs. Are you planting garlic this October?

For more information about growing garlic, but sure to read these expert articles:

• A complete garlic growing guide
• Garlic spacing: How far apart to plant garlic bulbs
• The best garlic varieties to grow
• How to grow garlic in pots