Lettuce Growing Calendar: Spring and Autumn Sowings

Two windows a year

Lettuce grows best at 59 to 68F (15 to 20C), so the sowings cluster where the temperature passes through that band, in spring and again in autumn. Spring is a race against the heat, autumn a race against the cold, and the failure you get from being late is the opposite in each case.

Read the timings below against your own climate. In a mild garden push the autumn sowing a week or two later. In a cold garden move the spring sowing a month later and treat it as a summer crop.

Sowing	Sow	Plant out	Harvest
Spring, heading	Late winter to early spring	Early to mid spring	Late spring to early summer
Spring, leaf	Early to mid spring	Mid to late spring	Late spring into summer
Late summer, heading	Late summer	Early autumn	Mid to late autumn
Autumn, leaf	Early to mid autumn	Mid autumn	Late autumn to early winter

Late winter into spring

The spring crop is sown while it is still cold and has to be finished before it turns hot. What you do in the earliest weeks is preparation rather than gardening, and the more of it you do the easier the rest is.

Then come the weeks of raising plants and the weeks of building outer leaves. If growth stalls for want of warmth there, the crop does not finish before the heat and bolting catches it. This is not the time to skimp on protection.

Stage	Jobs	The point
Deep winter	Prepare the bed, choose varieties	Get bolt resistant varieties in hand early
Late winter	Lime and compost, sow at the end of it	Sow under cover, with soil at about 59F (15C)
Early spring	Sow, raise plants, start planting out	Have row cover ready for late frost
Mid spring	Plant out, feed two weeks later	The month for outer leaves. Do not let it dry

Sowing early pays in spring. A week earlier gives you real margin against bolting at the far end.

Late spring through summer

Harvest, then clear, then prepare for the next sowing. Leaving plants standing after they are ready means they bolt, turn bitter and become a nursery for aphids.

In high summer the work is indoors rather than in the garden. The soil is too warm for germination, so you chill the seed to break dormancy and raise the plants somewhere cool before setting them out.

Stage	Jobs	The point
Late spring	Cut the spring crop	Press to test, and cut early if unsure
Early summer	Finish and clear the bed	Leave no bolted plants to feed aphids
Midsummer	Rest the bed	In cold gardens, start the autumn sowing
Late summer	Sow and raise for autumn	Chill the seed and shade the seedlings

To keep picking leaves through the hottest weeks, grow loose leaf or cut-and-come-again types under shade netting.

Autumn into early winter

An autumn crop grows into falling temperatures, so time lost early cannot be made up later. How closely you keep to plan with the sowing and planting decides the size of the head at the end.

Later in autumn the insects thin out and management gets easier, but rot at the base of the plant becomes more common after wet spells. Walk the bed on a dry day and pull anything that feels soft at the crown.

Stage	Jobs	The point
Early autumn	Sow for autumn, plant the late summer sowing	Net the bed as you plant
Mid autumn	Feed, start picking leaf types	Check the crowns after wet weather
Late autumn	Cut the heading types	Take the firm ones first, ahead of rain
Early winter	Finish and clear the debris	Take outer leaves and root stumps off the plot

Growth slows late in the season and everything takes about a week longer than the table suggests. Judge by firmness rather than by date.

What decides the outcome sits between the stages

The table shows where the jobs sit. What decides success is where in the window you do them, because with sowing and planting a few days changes the result. Watch the temperature and pick the day.

Record the sowing date Note when you sowed and when it germinated and next year's window becomes a number. A month is too coarse to identify what went wrong.
Plant at four or five true leaves The plant matters more than the calendar. Wait if it is not ready, and go early if it is getting away from you.
Feed two weeks after planting Count from the planting date, not the month. It is the feed that builds outer leaves, so late means a smaller head.
Harvest by feel, not by date Treat the day count as a prompt to check. The decision comes from pressing the head, or from the height and spread of a leaf type.

Tracing back a year that went wrong

What helps next year is settling on one stage where it went wrong. Look back at the record, decide whether it was the sowing, the planting, the feed or the harvest, and change one thing only.

What happened	Where it went wrong	The fix
Bolted without heading	Sown too late in spring	Sow at the earliest end of the window
The plant stayed small	Missed the feed two weeks after planting	Count from the planting date and do it
The autumn head never filled	Sown late in autumn	Sow at the start of the window
It split and rotted	Cut too late	Watch the forecast and cut early

Do not change the sowing date and the feeding in the same year, or you will not know which one worked. Change one at a time.

Written byYasuGrowing vegetables and fruit in Chiba, Japan, and building Gadenin. Corrections are welcome. 15 years of growing.