What to do now
Mildest step first.
- Leave the green shoots alone; don't cut them or dig the cloves up.
- Once the ground has frozen, spread 4–6 inches of weed-free straw or shredded leaves over the bed.
- If snow cover is thin and nights may drop into the teens, add another layer.
- In early spring, loosen or pull back the mulch so the leaves can come through.
Not sure this is it? Check other garlic problems
Why it happens
Fall-planted garlic is supposed to grow roots before winter. Whether it also sends up leaves depends mostly on the weather: after a long, mild fall, or when cloves went in early or shallow, green tips often show. University of New Hampshire Extension's advice is plain: if shoots start to grow in fall, don't worry; in most cases the garlic will survive the winter and come up unscathed in spring. Cornell says the same: even if garlic starts to emerge in fall, it will be fine.
Will the cold hurt it?
The leaves are tougher than they look. Iowa State notes that garlic foliage tolerates cold into the 20s°F, and that below about 20°F the leaves are likely to be damaged. Even when leaves are killed to the ground, the clove usually regrows. The cost is that a plant that loses a lot of leaf may make a somewhat smaller bulb, because it spent energy on growth it lost. University of Wisconsin Extension adds that shoots from shallow planting draw energy away from root growth and are usually killed over winter. So a little fall green is normal, but a lot, year after year, is a sign to plant later or deeper.
What to do now
Don't cut the shoots off, and don't dig the cloves up to check on them; either one only costs the plant energy. What helps is mulch. Once the soil has frozen, cover the bed with 4–6 inches of weed-free straw or shredded leaves. Mulch keeps the soil from freezing and thawing over and over, which can heave cloves out of the ground, and it shields the leaves. Iowa State suggests an extra layer where snow cover is poor and temperatures may drop into the teens; a steady blanket of snow helps too.
In spring
In early spring, check that the leaves can get through the mulch. Pull the straw back between rows or loosen it where it has packed down; by spring it has often compacted to about an inch. You can then rake it off to warm the soil, or leave it to hold moisture and add . Leaves that browned over winter usually push out fresh green growth from the center once the soil warms.
Next fall
Most extension guides time planting so roots form but leaves don't come up before winter. Recommendations vary by region: Penn State says about 3 weeks before the ground freezes, Illinois 4–6 weeks, Wisconsin 6–8 weeks, and Cornell 1–2 weeks after the first killing frost. In practice, if your garlic sprouted early this year, plant a week or two later next fall and set the cloves about 2 inches deep. Garlic that sprouted in your kitchen can be planted too; Wisconsin notes that storing bulbs above 40°F makes cloves sprout.
Growing it again? When to plant garlic for your ZIP code
- Why is my garlic so small?Small garlic most often comes from spring or late planting, small cloves, or leaving scapes on hardneck types. Plant the biggest cloves in fall, a couple of weeks after your first frost.
- Why are my garlic leaves turning yellow?Yellow lower leaves close to harvest are normal maturity. In spring, pale plants with yellow tips usually need nitrogen or better drainage. Orange spots mean rust; rotten bases or poor roots point to rot, bulb mites or nematodes.
- How do I know when to harvest garlic?Harvest garlic when roughly the lower third to half of the leaves have turned brown and dried while the upper leaves are still green — by then the bulbs have usually filled out and still have intact wrappers.
- What vegetables can I still plant in fall?Count back from your first fall frost: radishes and arugula need about 6 weeks, lettuce and spinach 7 to 8, roots and fall cabbage-family crops 10 weeks or more. Garlic goes in around the first frost.