The Warm-Season Vegetable Garden:
By Vincent Lazaneo
Snap beans, also known as green or string beans, are easy to grow and fun to harvest. The immature pods are ready to pick 50 to 70 days after planting. They can be eaten fresh from the garden while they are crisp and crunchy; cooked until tender and eaten warm, or chilled in a refrigerator and used later in salads.
Varieties with green pods are the most common. There are also varieties with yellow pods (wax beans) and others with purple pods which turn green when cooked.
Both bush and pole types are available. Bush beans mature a little sooner, but pole beans produce pods over a longer period and bear more in the same amount of space. Their tall vines need wooden stakes or a trellis for support.
Snap beans are tender, warm season annual plants that grow best in a sunny location. Seed can be planted in spring, after the dangers of frost have passed and the soil is warm. Seed will germinate slowly and may rot if the soil is too cold or too wet. Seeds can be sown from late March to early September in the San Diego area.
Before planting, mix compost and some complete fertilizer into the top foot of soil, then rake the surface level. Water well to thoroughly wet and settle the soil. After a few days when the surface soil is somewhat dry, plant bean seeds one-inch deep and cover them with moist soil. Do not water again until seedlings begin to emerge. For bush beans, plant seeds in rows one-inch apart. When they have their first true leaves, thin the seedlings, leaving one every 2-3 inches.
Provide support for pole beans by placing 6-8 foot tall wooden stakes one to two feet apart in a row. You can also use three or four poles tied together at the top to make a teepee for support. Plant up to six seeds near each pole and remove all but two or three of the strongest seedlings when they have their first true leaves.
Protect young seedlings from snails, slugs and birds. Poke a finger into the soil to check for moisture and water when it starts to feel dry one inch below the surface. When plants begin to flower, do not let the soil dry out – especially during hot weather or blossoms may drop.
Pods are ready to pick when they break easily with a snap. They should be harvested every three to five days. Plants will stop bearing if pods are allowed to mature.
Vincent Lazaneo is Urban Horticulture Advisor for UC Cooperative Extension. He helped found the San Diego County Master Gardener Association more than two decades ago and serves as its advisor. He is the author of numerous articles on plants and pests that appeared in the San Diego Union-Tribune, California Garden and other publications.