Agriculture Reference
In-Depth Information
chicory
Cichorium
intybus
artichoke
Cynara
scolymus
cardoon
Cynara
cardunculus
scorzonera
Scorzonera
hispanica
salsify
Tragopogon
porrifolius
burdock
Arctium
lappa
garland Chrysanthemum
Chrysanthemum
coronarium
Jerusalem artichoke
Helianthus
tuberosus
sunflower
Helianthus
annuus
LETTUCE
Lactuca sativa
WHAT YOU'LL NEED
• 10 healthy heads of lettuce
• rods or horizontally stretched netting
POLLINATION NOTES
Lettuce self-pollinates, with cross-pollination (usually by hoverflies) occurring
only rarely (2% of the time). Ten or so feet (a few meters) of separation between beds of lettuce suf-
fice. Plants that are not true-to-type in the next generation can simply be eaten and not further propag-
ated, though if some of these suit your fancy, allow them to go to seed. The variety 'Maikönig' (May
king) came to be in 1913 in this way, after being found in a plot of another variety.
GROWING FOR SEED
Find the best-looking heads of lettuce in your plot and place a stick or
something similar in the ground next to them to mark them. Never use the first heads of lettuce to bolt
for seed; this selects for early bolting—a trait that no gardener known to us finds desirable.
If you are planting a bed specifically for growing lettuce for seed, plan on each flowering plant re-
quiring about twice as much space in every direction as plants being grown for food.
When growing for seed, it is important to plant out as early as possible. All lettuce varieties (even
those that would normally be grown later) should be started in late winter to early spring. Seeds need
to then ripen in the driest period of the growing season. The exception here is winter lettuce, which
should be grown and selected in late summer.
Bolting heads of lettuce (especially iceberg lettuce) often need help with getting their flowering
stalks through the tight head of leaves. To this end, cut an X in the leaves with a sharp knife, taking
care not to cut so deep as to injure the stalk. Once plants bolt, check leaves at the base of the stalk of-
ten for signs of rot and remove as necessary to ensure the health and stability of the stalk. Flowering
lettuce needs additional support; they can be tied to, for example, the sticks you used to mark them in
the first place. For larger plots, stretch wide-meshed netting horizontally over poles at each corner,
through which the seed stalks of the lettuce plants can grow and be supported.
