Garlic is one of the easiest veggies to grow, but sometimes those big green tops yield a harvest of disappointingly small heads. After nearly a year of growing garlic from cloves by patiently watering, weeding and fertilizing, you'll want large flavorful garlic for your favorite recipes!
Here’s 9 steps to take, from pre-planting preparation through harvest, to help you grow your biggest garlic heads yet. In addition to following all of the garlic growing steps outlined below, it is important to plant your garlic at the right time.
Best Time to Plant Garlic
Plant garlic in the fall (September and October are best.) It should be at least 2 weeks before your first frost of the season. This affords your garlic the best possible chances to withstand winter conditions by giving it ample time to establish. November is late to plant garlic, December is marginal.
How to Grow Garlic
1. Select the best variety for your region
Not all seed garlic grows equally well everywhere. Most seed garlic requires sufficient cold temperatures in winter to develop good heads in spring, but some varieties are more tolerant of warm weather.
Hardneck garlic needs exposure to 40-50°F for 6 to 12 weeks for the biggest heads. Softneck garlic such as California Early White and California Late White are a good choice for warm climates.
If you live in an area with warm winters, avoid garlic described as “great for cold areas.” Growing garlic varieties that are not adapted to your climate can result in smaller heads.
2. Prepare the soil for planting
Garlic tolerates a wide variety of soils, but for large heads it is important to prepare your garden with the optimum nutrients and conditions before planting.
Garlic prefers:
- Loose, loamy soil with high organic matter content
- Soil with good drainage. Boggy or heavy wet soils can cause cloves to rot or develop poorly.
- If your garden soil is not suitable for garlic, consider growing it in a raised bed for better drainage.
- If you fertilize your garden, only do so between pre-planting time and late spring when scapes begin to form. Otherwise you could encourage too much top growth instead of head development.
- Be careful also of over-fertilizing with nitrogen-rich fertilizers in the fall, this could lead to stimulating top growth and result in frost damage in very cold winter areas. For details on soil preparation for garlic, see our Garlic Planting and Growing Guide.
3. Plant the biggest cloves
The biggest garlic heads grow from the biggest garlic cloves. Large garlic cloves have more energy stored up to help get your garlic off to a good start, and are more resistant to frost damage. When separating cloves for planting, select the largest cloves for growing garlic heads, and use the smaller ones for growing spring green garlic. Just harvest in spring when the leaves have grown, and use like garlic chives.
If you saved some of your harvested garlic for planting, select the larger of your heads for seed garlic and eat the smaller heads. While the larger ones are more appetizing, if you select larger heads for planting this year, you’ll have more big heads for both planting and eating in future years.
4. Give them room to grow
Plant your garlic with plenty of room for their roots to grow, and to keep the garlic from competing with each other for nutrients and water. Spacing them at 6 inches when planting is best. This also is close enough for them to provide some shade to each other while growing, which also helps with the next step.
5. Keep growing garlic cool
The biggest garlic experiences a long cool winter and early spring when it establishes its root system and prepares for head development, followed by a long (but not too hot) spring and early summer growth period when the heads grow and divide. Head growth starts when the soil temperature is around 60° F, and ends when the soil reaches 90° F.
The key to this step is to keep your garlic’s soil cool for as long as possible until it is ready for harvest. This will give it the longest time possible to develop large heads. If your soil gets too hot too early, head growth will stop when they are still small.
How to Keep Your Garlic Cool in the Summer
- Select a planting site that is shaded during the hottest part of the day.
- Mulch deeply with light colored material such as straw to help reflect light, insulate the soil from heat, and retain moisture – all of which keep the soil temperature lower.
- In areas where the ground freezes, mulching also protects the garlic from getting too cold. Compost, or Mega Mulch are also good mulch options.
- You can also shade your garlic patch with shade fabric.
6. Plenty of water
A good irrigation plan will also help to increase head size. Mulching helps to reduce evaporation, so your soil stays moist longer and less water needs to be applied. Water your seed garlic deeply but infrequently (allow the surface to dry out between watering, but keep it moist several inches down). This will encourage the roots to grow deeper to find water, instead of staying in the upper regions of the soil where the temperature is higher.
7. Weed your garlic beds
Weeds growing among your garlic provide unnecessary competition for nutrients and water. Weed your garden regularly! Mulching can also help to reduce the amount of weeds that sprout up.
8. Remove scapes right away
Scapes are the flower stalks that hardneck garlic produces in the spring and early summer. Check your growing garlic frequently for these, and remove them at leaf level. They’re good to eat, so don’t throw them out! They should not be allowed to grow because this takes energy away from head growth.
9. Harvest at the right time
Make sure that your garlic is fully grown before harvesting. When your garlic is ready, it will not grow anymore and is considered mature when the tops are a third (the 4 bottom leaves) brown or when it falls over (for softneck varieties).
When your garlic tops begin to yellow, stop watering them. Harvest garlic 2 weeks later and cure them. Don’t wait too long, or the papery covering will start to break down and they won’t store as well. Your garlic will not all be ready at the same time, so harvest each head as needed.
50 comments
This was my first year planting/harvesting garlic. My bulbs were mostly medium sized. I planted with compost last fall, covered with 6" of straw and fed seaweed foliar spray throughout the spring. Any suggestions for what else I can fertilize it with for larger bulbs? I’m not willing to use any animal derived products (fish, feather, bone, blood meal, etc.). Would compost or alfalfa tea be sufficient?
Erich, yes the high temps could be the cause of your small bulbs. Garlic bulbs stop increasing in size if the soil temp goes above 90F. You can either buy new seed garlic to plant this fall, or save your biggest cloves to replant this year. The bigger the clove the bigger the bulb will be the following year.
This is only the third time I’ve grown garlic, each planting was Nootka rose because of our success before. This year I got a crop of mostly small and a few medium sized cloves. Here in Seattle we’ve only ever hit 100 degrees four times, ever, until this year. In late June we had our three highest temperatures ever with the highest in our yard hitting 110. I suspect this is what caused our puney bulbs. Can I plant our smallest as is and expect them to be of good size next summer? Or should I buy new cloves at the nursery this fall and try again? Thanks for the article, Erich
Bev, yes you should add more soil to cover the garlic to at least the planting depth to what you originally planted them.
Our garlic was planted last fall at one end of a raised bed. The soil level in the bed has fallen quite a bit and I would like to add soil. Is it Ok to add over the garlic – probably 4 inches?