Onion and Garlic Growing Basics

How do onions and garlic differ in timing?

Garlic is usually planted in fall in many regions, wintering in the ground and harvested the following summer. Onions are often planted in spring, as sets, transplants or seed, and harvested in late summer. In mild-winter areas, schedules can differ. Planting dates also depend on your soil: wet, cold ground rots sets and cloves, while hard frozen soil blocks planting altogether.

Ask your extension office for local planting windows, since climate changes what works.

Plan the bed for the long run. Garlic occupies space from fall to the following summer and onions most of the season, so place them where taller crops will not shade them and where later plantings will not be disturbed.

Which onion type should I choose?

Onions form bulbs based on day length. Short-day, intermediate-day and long-day varieties suit different latitudes, so choose varieties labeled for your region. Choosing the wrong type gives small bulbs or none.

Sets are easiest, transplants give a good start, and seed offers the most variety but takes longest. Seed-grown onions take the most patience but let you choose from the widest range of varieties, while sets cost little and forgive mistakes, which makes them a good first try.

Keep onion planting shallow. Sets and transplants should have the base covered but the bulb shoulders near the surface, since deep planting can delay bulbing. Firm the soil and water after planting to settle roots.

• Short-day: southern areas
• Long-day: northern areas
• Intermediate: between
• Check labels or ask your extension office

How do I plant garlic?

Use garlic labeled for planting from a trusted source, since supermarket bulbs may carry disease or be unsuited to your climate. Separate cloves just before planting and plant pointed end up in loose, well-drained soil.

Mulch lightly after the ground cools to protect cloves through winter. Remove mulch gently in spring as shoots emerge.

Green onions can be pulled at any stage and are a quick way to use thinnings. Many gardeners plant extra sets for early green onions and leave the rest to mature.

• Loose, well-drained soil
• Plant pointed end up
• Mulch after the ground cools
• Use planting-quality bulbs only

How do I prepare soil and space plants?

Both crops need loose, fertile, well-drained soil and full sun. Poor drainage invites rot. Follow packet or extension spacing, because crowded bulbs stay small.

A soil test guides feeding. Onions and garlic have shallow roots, so keep competing weeds out by hand or with a shallow hoe, and avoid disturbing roots.

Garlic scapes are curling flower stalks produced by hardneck types. Removing them is a common practice that directs more energy to the bulb, and the scapes can be eaten. Ask your extension office whether your variety makes them.

• Full sun all day
• Fertile, well-drained bed
• Shallow weeding by hand
• Keep even moisture early

How do I water and feed them?

Even moisture helps bulbs size up, especially in spring growth. Reduce watering as bulbs mature and tops begin to fall, which helps with curing.

Feed early in growth based on the test and label, and stop feeding as bulbs begin to form. Late nitrogen can delay maturity and reduce storage quality.

Watch the weather during curing. A rainy spell can spoil bulbs left outdoors, so bring them under cover with good airflow and avoid stacking them in thick piles.

What problems should I watch for?

Onion maggots, thrips, white rot, downy mildew and neck rot can affect crops. Rotate onions and garlic away from the same family for several years, since some diseases persist in soil.

If you see yellowing, wilting or white fluffy growth at the base, ask your extension office. Do not compost diseased bulbs.

• Yellowing tips and wilting
• White fluffy growth at base
• Thrips damage on leaves
• Soft, rotting necks

When and how do I harvest, cure and store?

Harvest when tops fall over and begin to dry, or when garlic leaves yellow partway up. Lift bulbs gently with a fork and avoid bruising. Cure in a dry, shaded, airy place until necks are tight and outer skins papery. Do not wash bulbs before curing, and cut tops only after necks have dried, since cutting early leaves an open wound for rot.

Store cured bulbs cool, dry and ventilated. Use damaged or thick-necked bulbs first. If you plan to preserve, use a current tested recipe from the National Center for Home Food Preservation. Garlic in oil is a botulism risk, so never improvise with it.

Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.