Garlic

Plant garlic nowOct

Set cloves 2in deep pointy end up 6in apart in rich soil then mulch. Fall planting roots before winter for big summer bulbs.

An inch of water a week while the leaves are growing

Soak the soil thoroughly rather than sprinkling it, giving at least one inch of water per week through the growing season. Leaf growth in spring sets how large the bulb can get, and shallow-rooted garlic cannot chase water down the profile the way a deeper-rooted crop can.

Stop watering two weeks before you lift

Cut off irrigation about two weeks ahead of harvest and let the bed dry down. Wet soil in the last two weeks stains and rots the papery wrappers that protect the bulb in storage, and damp bulbs going into curing invite disease.

Mulch the bed right after planting

Lay 2 to 4 inches of straw or shredded leaves over the bed as soon as the cloves are in. Use straw free of weed seed. You can pull the mulch back in spring or leave it in place to hold down weeds. The cloves root through late fall and need stable soil. Mulch keeps freeze-thaw cycles from heaving the cloves out of the ground, blunts cold damage to emerging shoots, and holds moisture.

Feed nitrogen twice in early spring, then stop

Side-dress nitrogen as soon as the shoots push through, then once more two to three weeks later. Stop feeding nitrogen once the plants start to bulb in late spring - do not keep feeding into the bulbing period. Garlic builds its leaves first and every leaf becomes a bulb wrapper, so early nitrogen sizes the bulb. Nitrogen applied after bulbing has begun pushes leaf growth instead and delays bulbing.

Cut the scape as soon as it appears

On hardneck garlic, cut off the curling flower stalk as soon as you can see it. Softneck types do not make one, so there is nothing to cut. The scapes are good eating - do not throw them out. Left on the plant, the scape competes with the bulb for nutrients and you get a measurably smaller, poorer bulb. Cutting it redirects that energy underground.

Inspect your seed cloves before you plant them

Before planting, dissect a few cloves where the roots meet the bulb and look for bulb mites - creamy white, bulb-shaped mites with a bulbous rear end and many long fine hairs, clustered under the scales. Reject any lot whose basal plate separates easily from the bulb or whose cloves are shrunken and soft. Plant only clean seed from a clean field. Bulb mites ride into the ground on infested seed cloves, and there is little that can be done chemically once they are there - the wounds they cause also open the door to Fusarium dry rot, Botrytis, and soft rot. Starting with clean bulbs is the control.

⚠ Hot water treatment of seed cloves at 130F for 10 to 20 minutes is an option but it will decrease germination - sourcing clean seed is the better path. Separately, per UMaine Extension Bulletin #1205 (https://extension.umaine.edu/publications/1205e/): if bloat nematode has been confirmed in a field, do not replant any garlic from that field, because bulbs from an infested field may look symptomless yet still harbor low levels of the nematode.

Watch for white rot and pull suspect plants

Walk the bed in spring looking for stunted plants or yellowing lower leaves. Tug a suspect plant - if the roots have rotted it lifts out easily. Check the base of the bulb and stem for fluffy white growth and tiny black specks. Remove suspect plants, keep tools and boots out of the rest of the garden, and contact your extension office to confirm. Do not till infected plants under and do not compost them - dispose of them off-site. White rot sclerotia survive in soil for as long as 40 years even with no onion or garlic present, and as little as one to two sclerotia per pound of soil will infect every plant. The fungus also grows straight through the soil from one plant to its neighbor, so a small patch spreads outward.

⚠ There is no fungicide for white rot in the home garden - do not spray for it. If it is confirmed, stop planting garlic and onions in that ground; crop rotation is of limited use because the sclerotia outlast any rotation. Sanitize tools and equipment with an approved quaternary ammonia product.

Harvest garlicJul

Lift when the lower 3-4 leaves have browned then cure in shade 2-3 weeks. Pulled too late the bulbs split and won't store.

Cure the bulbs until the outer two leaves are dry

Put the lifted plants on racks with good airflow, out of direct sunlight and out of the weather, for about three to four weeks - until the outer two leaves are completely dry. Then trim the tops half an inch to an inch above the bulb, cut the roots close to the base, and clean the remaining soil off. Store the cured bulbs in clean cardboard boxes or burlap bags at 32 to 35F and 65 to 75 percent relative humidity. Curing seals the neck and dries the wrappers, which is what keeps a bulb sound for months. Bulbs stored damp or bruised go to blue mold, black mold, and neck rot, and warm humid storage accelerates all three.

⚠ Do not trim the tops too close to the cloves and handle the bulbs gently - trimming injuries and bruises are exactly where blue mold and black mold get in.