Lettuce at a glance
| Botanical name | Lactuca sativa |
|---|---|
| Family | Asteraceae |
| Other names | leaf lettuce, romaine, butterhead |
| Plant type | Vegetable; cool-season annual |
| Size | 6 inches to 1 foot tall and wide |
| Light | Full sun (6 or more hours of direct sun); Part shade (2 to 6 hours of sun) |
| Water | Keep soil evenly moist; shallow roots dry out fast. |
| Soil | Loose, fertile, well-drained soil. |
| USDA hardiness zones | Grown as a cool-season annual in every zone. |
| USDA PLANTS symbol | LASA3 |
When to plant lettuce
Sow outdoors 2 to 4 weeks before your last spring frost. Sow again in late summer for a fall crop.
Turn these into real dates for your area with the planting calendar.
How to grow lettuce
- Sow seeds thinly and very shallowly; lettuce seed needs light to sprout.
- Keep the seedbed moist until seedlings appear.
- Thin plants so heads have room.
- Sow a short row every two weeks for a steady supply.
- Pick outer leaves of leaf types, or cut whole heads.
- Give afternoon shade as weather warms to slow bolting.
Water and soil
Water: Keep soil evenly moist; shallow roots dry out fast.
Soil: Loose, fertile, well-drained soil.
Light: Full sun (6 or more hours of direct sun); Part shade (2 to 6 hours of sun).
Common problems
- Bolting
- Hot weather makes plants send up a flower stalk and turn bitter. Grow in spring and fall, and choose slow-bolting varieties.
- Slugs
- Ragged holes and slime trails. Hand-pick in the evening and keep the area tidy.
Is lettuce safe for cats and dogs?
Not listed
Not listed
Lettuce is not on the ASPCA's toxic or non-toxic plant lists for cats and dogs.
NC State Extension rates its poison severity for people and animals as low.
If a pet chews a plant and you are worried, call your vet or the ASPCA Animal Poison Control Center (888-426-4435; a fee may apply). For people, call Poison Help at 1-800-222-1222. In an emergency, call 911.
Can you eat lettuce?
The leaves are eaten raw or cooked.
Lettuce questions
When should I plant lettuce?
Sow it outdoors 2 to 4 weeks before your average last spring frost, and again in late summer for fall. Lettuce prefers cool weather.
Is lettuce safe for pets?
Lettuce is not on the ASPCA's plant lists. Ask your vet before feeding any new food to a pet.
Why does my lettuce taste bitter?
Heat and drought make lettuce bitter, often as it starts to bolt. Harvest before hot weather and keep the soil moist.
Sources
- NC State Extension Gardener Plant Toolbox: Lactuca sativa (size, light, soil, zones, poison rating)
- USDA PLANTS Database profile: Lactuca sativa L. (accepted name)
- ASPCA Animal Poison Control: plants toxic and non-toxic to cats
- ASPCA Animal Poison Control: plants toxic and non-toxic to dogs
- Colorado State University Extension: Growing Annual Plants from Seed
- Colorado State University Extension: Vegetable Planting Guide
Written in our own words from the sources above. See our editorial policy. Spotted a mistake? Tell us.
