Saturday, March 12, 2005,
By PAT HITCHCOCK, UC.Master Gardener
You don't have to be a Master Gardener to notice that spring has arrived in the Napa Valley. Mustard and daffodils bloom in gardens and along roadways, roses and other perennial plants are putting on new growth. Weeds are everywhere, growing faster than we can pull or mow them.
Now is the ideal time to plant salad greens. They're easy to grow any time, but particularly easy in the spring when conditions are exactly what most greens like: mild temperatures with no hot spells and, if we are lucky, sufficient moisture in the form of rain.
Lettuces are the classic salad greens. A peek at the lettuce selection in a seed catalogue reveals endless variations of colors from pale green to dark green to red and many combinations, as well as leaves that range from basic smooth to fancy shapes and textures. They are so beautiful that you could grow them as ornamentals.
For growing purposes, they are classified into four types; crisphead, butterhead or Boston types, Romaine or Cos lettuce, and the loose-leaf varieties. 'Iceberg' is the popular crisphead variety that likes to mature in cool weather. Butterhead types have green smooth-leaved loose heads with inner yellow leaves. Romaine has upright growth with overlapping leaves that may be picked individually as the plant grows. The loose-leaf varieties, which form rosettes, are the easiest to grow. These can be grown for harvesting as soon as the leaves are big enough to taste.
In addition to all the choices of lettuces, there are dizzying arrays of other types of greens, which are delicious and nutritious additions to the spring salad garden. Some of these greens are endive, mustard, arugula, radicchio, mache, kale, mizuna and beets.
If you are a gardener with a limited amount of energy and time to spend, you will have to make some choices as to which ones to try. Fortunately, seed companies and nurseries carry mixtures of seeds so that you can have a variety of salad greens with a small outlay of cash. Widely available are mesclun mixes, which usually include lettuces mixed with other greens to be sown together. In my garden, I have found that lettuces sprout and grow a little bit slower than the other greens, so I prefer to grow them separately. The seed mixtures will specify what varieties are included. I've had great success with packets labeled "Asian" greens.
All salad greens like loose, well-drained soil. Amend with compost or well-rotted manure and plan to fertilize lightly during the growing season. You can get a quick start by buying seedlings ready for transplant at local nurseries, but you'll get more choices of varieties and types if you start from seed. I usually plant two rows in a bed about 18 inches wide; and I only plant about six feet at a time, half of it mixed lettuce and half other mixed greens. The seeds are small so you barely cover them with soil. Sift some fine compost lightly onto the top to hold in moisture, and gently sprinkle if the soil surface looks dry.
Once the seeds sprout, irrigate whenever there is less than an inch of rain in a week. Pay attention to weeding and thinning while the seedlings are small. Each plant needs a minimum of four inches of row space or more if you intend to let them grow to their full mature size. Control slugs and snails by hand-picking or baiting. Spray off aphids and earwigs with a strong jet of water.
Harvest begins whenever the plants are large enough to recover from the loss of leaves and continues until the plants start to form flowering stems, when the leaves tend to get tough and lettuces start to taste bitter. This will happen sooner if the weather turns warm. Early in the season you may pick greens from the same bed for about six weeks, but for a longer season of sweet and tender salads, you need to plant successively. If your initial planting is at the beginning of March, plant another patch by the beginning of April and after that, every two to three weeks.
Harvest in the morning when the air is cool and the plants are fresh and crisp. I pick leaves and sometimes small whole plants that need to be thinned out, wash them immediately in the bowl of my salad spinner, spin them and store them in a plastic bag in the refrigerator. When lunch or dinnertime comes, salad making can be as simple as making a dressing. Your homegrown greens will be tasty as well as beautiful.