Garlic
Allium sativum
Amaryllidaceae · onion family
- Matures
- 120–185 days
- Harvest
- Once · Annual
- Sun
- 6–8+ hrs
- Spacing
- 3–5 in
Planting window
When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.
| Jan | Feb | Mar | Apr | May | Jun | |
|---|---|---|---|---|---|---|
| Foggy | ● | ● | ||||
| Sunny | ● | ● |
| Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|
| Foggy | ● | ● | ● | |||
| Sunny | ● | ● | ● |
Sunlight
How well it does at each level of direct sun per day.
Soil depth
Root room it needs — useful for sizing raised beds and containers.
Spacing
Room each plant needs — along the row and between rows — for sizing beds.
- In-row
- 3–5 in
- Between rows
- 12–18 in
Growth habit
The shape it makes in the bed and how tall it gets — what tells you whether to give it a trellis, a stake, or just room.
- Habit
- Upright
- Mature height
- 12–18 in
Stands on its own; the tallest types appreciate a stake in wind.
How to start it
Sow it where it grows, or raise it under cover and set it out — and how far ahead to start the seedlings if it's the latter.
- Usually
- Direct-sow
Sown straight into the bed it will grow in.
Getting started
How it goes in the ground — how deep to sow or set it, and the soil temperature it needs to wake up. The cold-soil floor is the real limiter for direct-sowing in a foggy SF spring.
- Started from
- From cloves
- Ideal soil temp
- 65–85°F
- Set depth
- 2–3 in
Sprouts between 32–95°F; happiest around 65–85°F.
Pests & diseases
What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.
Pests2
Thrips
- What it is
- Most adult thrips are elongate, slender, minute (less than 1/20 inch long), and have long fringes on the margins of both pairs of their long, narrow wings. Immatures (called larvae or nymphs) are oblong or slender and elongate and lack wings.
- What you'll see
- Thrips feeding on plants can damage fruit, leaves, and shoots and very noticeably affect plants’ cosmetic appearance. However, thrips rarely kill or threaten the survival of trees and shrubs.
- What to do
- Thrips species that feed on many different plant species often move into gardens and landscapes when plants in weedy areas or grasslands begin to dry in spring or summer. Avoid planting susceptible plants next to these areas, and control nearby weeds that are alternate hosts of pest thrips.
Onion Maggot
- What you'll see
- White worm that feeds on seedlings, roots or bulbs.
- What to do
- Use crop rotation, avoid excessive amounts of organic matter, and apply insecticides at planting if maggots have been a problem in the past. Destroy infected plants.
Diseases1
Neck Rot
- What you'll see
- Fungal disease that occurs during storage. Watery decay inside the bulb.
- What to do
- Avoid excess moisture near harvest. Cure bulbs well before storing.
Sources
Every figure above is backed by these.
- UC Master Gardeners, San Mateo–SF Countiesbacks plantingWindow, startMethod · Foggy & Sunny calendars, Garlic (sets) row: plant Jan-Feb & Oct-Dec in both microclimates. Start method: Foggy & Sunny calendars, Garlic row: cloves planted in place.
- Golden Gate Gardening (Pam Peirce)backs sunlight, lifecycle, harvestStyle · Garlic is a full-sun allium, best in 6+ hrs direct sun. Habit and harvest: annual, once — from this source's entry for this crop.
- UC Master Gardeners, Sonoma County (Planting Summary)backs daysToMaturity, inRowSpacing, rowSpacing · Vegetable Planting Summary, Garlic row: 120-185 days, 3-5 in in-row spacing. Between-row spacing 12-18 in (Garlic row).
- Utah State University Extensionbacks soilDepth, plantingDepth, startMethod · 'How to Grow Garlic in Your Garden' (USU Extension): 'rooting depth in garlic is shallow' — shallow-rooted, workable in the shallowest beds. Planting depth 2-3 in (cloves): 'Plant the largest unpeeled cloves with the pointed end up 2-3 inches deep.' Start method: USU Extension garlic: 'Plant the largest unpeeled cloves with the pointed end up 2-3 inches deep' — set directly in the bed.
- UC Master Gardeners, Sacramento County (Germination)backs germination · GN 154 Garlic row: 32/65–85/95°F (listed as germination temp; garlic is grown from cloves, which likewise root in cool soil).
- USDA GRIN Taxonomybacks botany
- NC State Extension — Plant Toolboxbacks growthHabit · Allium sativum (Garlic) entry: Height '1 ft. 0 in. - 1 ft. 6 in.' (12-18 in); Form 'Erect' — flat, upright strap-like leaves fanning from a central stem over the bulb, so classified upright.
- UC Master Gardeners, Santa Clara Countybacks startMethod · Start method: Planting chart: Garlic carries a 'Plant cloves' row only, From seed to transplant Not applicable.