Long-time vegetable gardeners almost always recommend growing expensive produce like Chinese peas, and not wasting time on zucchini which is cheaper in the market than you can raise it at home. So mesclun is a good candidate for your back yard or for pots on your lanai.
Mesclun originated in the south of France, and the name comes from the Nicois word "mesclumo," meaning a mixture. The French mix traditionally calls for chervil, arugula, loose-leaf lettuce and endive, but locally the preference is for a combination of mizuna, arugula, Manoa lettuce and coarse greens - oakleaf lettuce, mustard greens, endive or young spinach leaves.
These are all grown from seeds, and may be bought separately or from mixed blends called by such names as spring salad, Nicoise, stir-fry greens or Provencal mix. Occasionally, one of the boutique nursery catalogs will label their mix as mesclun, but the seeds generally go under more generic names.
Most local garden shops are careful to import only the seeds that will grow here. Certain lettuces need a cooler climate and will bolt - prematurely go to seed by shooting a long stalk up the center of the plant - in our warm weather. The lettuce is then inedible. But read the label, and make sure the plants are appropriate to Hawaii.
During the summer, frequent planting and prompt harvest are important, and the more delicate plants should be kept in the shade during hot afternoons. Loose-leaf varieties like oakleaf and Manoa are easiest to grow here. If your night temperature exceeds 80 degrees, wait for cooler weather to sow lettuce seeds.
Lettuce grows best in a rich, loamy, loose soil with good drainage. These plants have shallow roots, and will benefit from an inch or so of organic fertilizer or compost worked into the soil. They will also grow well in containers, and most of them are decorative enough to be on a lanai.
Sow the seeds in successive plantings since this is a fast growing crop that matures in about five weeks. If you plant the seed mixes every 10 days to two weeks, you will have mesclun for salads and stir-fry all year long. In the summer, be sure that the plants are shaded in midday.
First moisten the soil, then make shallow furrows about 1/4-inch deep. Sow the seeds and then cover the furrow. Keep the seeded area moist. Mulching the soil around the plants holds the moisture and keeps the temperature down around the shallow roots.
Mesclun is harvested when the leaves are small and tender, so soil preparation is an important factor. The soil must be kept moist, but not soggy, and should not be allowed to dry out. Dry soil causes the lettuce to be bitter, and encourages bolting.
Begin harvesting when the the plants are about two inches tall. Mesclun should be picked early in the morning when the leaves are crisp. Heat causes the leaves to wilt. Use scissors to harvest the greens, and never let the plants get more than 6 inches tall.
By harvesting with scissors rather than pulling up the lettuce, the crop will continue to grow. Cut the leaves just below the growing crowns. Since some of the varieties grow faster than others, your salads will differ from harvest to harvest.
Rinse the leaves in cool water, drain on paper towels and pat dry. If you spin-dry the greens, use them immediately because this process bruises the leaves and they will quickly become limp. Wrap the leaves in slightly damp paper towels, seal in a plastic bag and store in the refrigerator.
The greens should be fresh for several days. If they become slightly wilted, they will revive by crisping them in cool water for about 10 minutes. Stir-fried mesclun can be added to pasta dishes or to other fresh vegetables.
Loose-leaf lettuces, the major constituent of mesclun, are loaded with Vitamin A and are high in potassium, but they are skimpy in calories. Nothing much bothers lettuce, and the occasional aphids can be hosed off. Lettuce doesn't need fertilizer because it is harvested so early, and of course, the plants should never be sprayed with chemicals.
This is a good time to begin a salad garden, before the heat of summer comes. Because of the short period from seed to kitchen, you can change the mix several times within a few months. There is a basic satisfaction in growing food for the table, and lettuce is one of the easiest of the edibles. And you will be very pleased with yourself when you pass up on the $1 per ounce mesclun at the supermarket.