Time to plant
Lettuce includes head lettuce and loose-leaf lettuce.
They are ideally suited to many parts of California.
They are hardy, cool-season vegetables. Their cultural
requirements are similar. Ideally, they are best grown
when the average air temperatures are between 73° F
during the day and 45° F at night. The
growing season can be extended by using a floating row
cover, which offers a few degrees of frost protection
and provides a warmer growing environment. At higher
temperature ranges, lettuce may bolt and become bitter.
Loose, fluffy heads and tipburn may also be caused by
high temperatures. At temperatures near freezing, young
plants are not damaged, but growth is slow. Optimum temperatures
for germination range from 68° to 77° F. Above 86° F,
seed germination is inhibited.
Lettuce is suitable for a small garden if compact varieties are grown. In suitable climates, these
crops can be planted more than once a year for a continuous harvest.
Dates for Lettuce*
or direct seed
North and North Coast
Monterey County north
San Luis Obispo County south
Sacramento, San Joaquin valleys
Imperial and Coachella valleys
*Transplants may be started indoors 4 to 6 weeks before
the last frost date. Areas are large, so planting dates
are only approximate, as the climate may vary even in small
sections of the state. Contact experienced gardeners in
your community and experiment on your own to find more precise