Gardening Articles: Care :: Seeds & Propagation
A Bounty of Beans (page 3 of 4)
by Susan Littlefield
Beans are susceptible to a number of bacterial and fungal diseases. Bacterial blights cause small, water-soaked spots on the leaves that enlarge, turn brown and can eventually kill the leaf. Lesions may also appear on stems and pods. Common blight can be a problem east of the Rockies, especially when the weather is hot and humid. Halo blight is more of a problem when the weather is cool. You can keep these diseases to a minimum with good garden sanitation. Remove infected plants and clean up or bury plant debris at the end of the season, try to have a 3-year rotation for the location of bean plants in the garden and avoid working in bean patch when the leaves are wet. White mold is a fungal disease that causes water-soaked spots on leaves, stems and pods. When the weather is moist, a fuzzy white mold forms on these spots. You may see what look like small, black, seeds in the mold. To control white mold, plant in well-drained soil, avoid overhead watering or water early in the day so plants dry quickly, space plants widely to encourage good air circulation and rotate crops. A fungicide can be used if the problem is severe, but it will not cure the disease, only prevent its spread.
The Mexican bean beetle is found in most parts of the country. This pest looks something like a ladybug, but it's definitely not beneficial! The 1/4-inch long, reddish adult beetles have 16 black spots on their backs; the orange-yellow, soft-bodied, spiny grubs also dine on bean leaves. The tissue between the veins will be eaten, giving the leaves a lacy appearance. Adults overwinter in plant debris, so clean up the garden well at the end of the season. Look for and squash yellow eggs on the undersides of leaves. Handpicking adults will often control the problem. Pyrethrin sprays can be used for a more serious infestation; be sure to spray the undersides of the leaves where these pests feed. Floating row covers can prevent damage to young plants, but you'll need to remove them once plants begin to flower so pollinators can reach the blossoms.
Bush and pole beans are ready to pick when their pods are firm and crisp, but the seeds within the pods are still undeveloped. Harvest by holding the bean stem in one hand and carefully pulling off the individual beans with the other. Pick often- the more you pick, the more the plant will produce. Shell beans are ready when the pods are full and green. Let your dry beans mature on the vine until the pods dry begin to split.