Now is the time to switch to those varieties of lettuce
that remain sweet through the heat of summer. Here are a few varieties
that I have experimented with and found dependable in summer.
– an open headed romaine developed in Israel that remains
sweet at temperatures in the low 100’s, is slow to bolt and
remains sweet while bolting, until the flowers open. It is also
very cold tolerant.
Matchless – a
true bib lettuce that remains sweet and soft in summer and grows
vigorously in our alkaline soil
Red Sails – a
loose leaf lettuce with beautiful color – does not tolerate
drought well, but remains soft if given adequate water
Nevada – a Batavia
type that seems slower growing than the other varieties, but has
excellent flavor and texture
Craquerelle du Midi
– a romaine that grows vigorously and is fairly drought tolerant
Growing good lettuce in summer requires a little different
approach to cultivation than during gentler times.
Lettuce seed will go dormant at about 80°F, and since it requires
light to germinate getting it started in summer can be challenging.
The cues to germinate are moisture and a cool temperature, which
can be met by placing the seed on a moist paper towel and holding
it bagged for 2-3 days. After cueing, the seed cannot return to
“dormancy” and can be sown in warm soils with good germination.
I have had good results in summer by starting lettuce in six packs.
For a continuous supply of high quality lettuce, start seeds every
It is best to transplant them young, when they have 3-4 true leaves,
and provide afternoon shade until they establish a vigorous root
system. Mulching helps keep the soil cooler and more evenly moist.
Growing – Adequate
water is essential to maintain table quality. Lettuce that is water
or nutrient stressed will be tough and bitter. Afternoon shade and
some wind protection make it easier to grow high quality lettuce.
When the lettuce starts to mature, cut the entire plant a couple
of inches above the soil – for a “cut and come”
second harvest or just below the soil to make room for new transplants.
Harvesting – I
have had excellent results by carefully picking the outer (larger)
leaves rather than waiting for the entire plant to reach maturity
or using the “cut and come” method.
The Cooks Garden
– carries all varieties, except Jericho, along with others
and a “Summer Lettuce” Mixture.
Seeds of Change
– carries Jericho
Good growing and good eating with
those sweet and juicy summer salads
Doña Ana County Extension Master Gardener