Description
Green beans, also called "string beans" or "snap beans," are tender annuals. Though most green beans are indeed green, they also come in purple, red, yellow, and streaked varieties. Their growing style is classified as "bush" or "pole." Bush beans grow compactly while Pole beans grow as climbing vines. In Sri Lanka, both types are cultivated, with pole beans being particularly popular in home gardens.
Planting requirements
Planting season: Year-round in most parts of Sri Lanka, with the best seasons being March-April and November-December
Planting conditions:
| Propagation | Seeds |
|---|---|
| Planting method | Sow bush beans 1 inch deep and 2 inches apart in rows 18 inches apart. Sow pole beans 1 inch deep, placing them around supports |
| Soil | Need a well-drained loamy soil that has been improved by compost and a pH of about 6.5. Incorporating compost when digging the soil is better. Better to prepare the soil about a week before planting. Avoid using high nitrogen fertilizer |
| Water | Need to keep the beans well watered otherwise they will stop flowering |
| Light | Needs full sunshine for most part of the day |
Growing conditions:
| Temperatures | Thrives in temperatures between 18Β°C to 30Β°C, which is common in most parts of Sri Lanka |
|---|---|
| Soil | Keep the bed well-weeded and the soil loose. Mulch soil around bean plants to retain moisture but keep it well drained. Beans have shallow roots, so mulch keeps them cool |
| Water | Water regularly, about 2 inches per square foot per week. Better to water them on a sunny day so that foliage will not remain soaked, which could encourage disease. Drip irrigation system recommended |
| Pruning | Pinching off the tips of plants after they have produced pods can encourage further production. |
| Weed control | Hand-pull weeds or use organic herbicides to keep weeds at bay |
Harvesting
Days to harvest range from 50 to 70 days. Green beans are picked young and tender before the seeds inside have fully developed.
Curing
Green beans do not require a curing stage.
Storage
Store green beans in a plastic bag in the refrigerator crisper drawer for up to 7 days (the plastic bag ensures moisture retention). For longer storage, blanch beans in boiling water for 3 minutes and cool in ice water for 3 minutes. Drain and package to keep in the freezer.
Protecting your plants
Pest control
Pest type:
- Aphids (Cowpea aphid, Pea aphid)
- Armyworms (Beet armyworm, Western striped armyworm)
- Corn earworm
- Cutworms
- Leafminers
- Loopers (Cabbage looper, Alfalfa looper)
- Mexican bean beetle
- Stinkbugs (Consperse stinkbug)
- Spider mites (Two-spotted spider mite)
Symptoms:
- Aphids: Small soft-bodied insects on underside of leaves and stems; yellowing, distorted leaves; necrotic spots; stunted shoots; honeydew secretion
- Armyworms: Circular holes in foliage; skeletonized leaves; shallow wounds on fruit; egg clusters on leaves
- Corn earworm: Damage to leaves, buds, flowers, pods and beans; young caterpillars cream-white with black head; older larvae yellow-green to black with fine white lines
- Cutworms: Severed stems of young plants; irregular holes in fruits; larvae curl into C-shape when disturbed
- Leafminers: Thin, white, winding trails on leaves; white blotches; premature leaf drop
- Loopers: Large or small holes in leaves; pale green caterpillars with white lines; distinctive arching movement
- Mexican bean beetle: Irregular patches on leaf undersides; lacy leaf appearance; damage to flowers and pods
- Stinkbugs: Dark pinpricks on fruit surrounded by lighter area; secondary infections and fruit decay
- Spider mites: Yellow stippling on leaves; bronzed appearance; webbing on leaves; tiny moving dots visible with hand lens
Control method:
- General: Monitor plants regularly; remove plant debris; use resistant varieties when available
- Aphids: Prune infested parts; use reflective mulches; spray with strong water jet; apply insecticidal soaps or neem oil
- Armyworms: Encourage natural enemies; apply Bacillus thuringiensis
- Corn earworm: Monitor for eggs and larvae; apply Bacillus thuringiensis or Entrust SC for organic control
- Cutworms: Remove plant residue; use protective collars around stems; hand-pick larvae at night; apply diatomaceous earth around plant base
- Leafminers: Check transplants before planting; remove plants after harvest; use insecticides only when necessary
- Loopers: Hand-pick larvae; apply Bacillus thuringiensis
- Mexican bean beetle: Plant early varieties; remove overwintering sites; hand-pick adults and larvae; destroy eggs
- Stinkbugs: Remove weeds around crop; use insecticidal soaps or kaolin clay; preserve natural enemies
- Spider mites: Maintain proper irrigation; spray plants with water jet; apply insecticidal soap if necessary
Disease Control
Disease type:
- Alternaria leaf spot
- Anthracnose
- Bean rust
- Black root rot
- Fusarium root rot
- White mold (Sclerotinia timber rot)
- Bacterial blight
- Bacterial brown spot
- Halo blight
- Damping-off
- Mosaic (Bean common mosaic virus, Bean common mosaic necrosis virus)
Symptoms:
- Alternaria leaf spot: Small brown lesions on leaves; lesions expand and turn gray-brown with concentric zones
- Anthracnose: Dark brown to black lesions on cotyledons, stems, and pods; sunken cankers; reddish-brown spots on pods
- Bean rust: Small yellow/white spots on leaves; raised brick red rust pustules; premature leaf drop
- Black root rot: Red-purple lesions on roots turning dark gray to black; stunted growth; wilting; defoliation
- Fusarium root rot: Stunted plants; chlorotic leaves; leaf drop; decayed, hollow roots
- White mold: White, cottony fungal growth on flowers; dark green, water-soaked lesions; plant death
- Bacterial blight: Water-soaked spots on leaves; necrotic areas with yellow borders; sunken lesions on pods
- Bacterial brown spot: Dark brown necrotic spots on leaves; water-soaked spots on pods; pod distortion
- Halo blight: Small water-soaked spots on leaves; chlorotic halos; distorted leaves; lesions on pods
- Damping-off: Seed rot; seedling death; stunting and yellowing of older plants; reddish-brown lesions on roots and stems
- Mosaic: Mottled dark and light green patterns on leaves; leaf distortion; stunted growth
Management:
- General: Use certified disease-free seeds; practice crop rotation; remove and destroy infected plant debris
- Alternaria leaf spot: Ensure proper soil fertility; apply foliar fungicides if necessary
- Anthracnose: Plant resistant varieties; avoid overhead irrigation; plow crop debris into soil
- Bean rust: Remove infected crop debris; follow crop rotation; spray suitable fungicide if severe
- Black root rot: Rotate crops with non-susceptible plants; avoid irrigation extremes
- Fusarium root rot: Practice long-term crop rotation; maintain proper irrigation
- White mold: Rotate with non-host crops; plant rows parallel to wind direction; avoid excessive nitrogen
- Bacterial blight: Treat seeds with antibiotics; use copper-based fungicides preventively
- Bacterial brown spot: Remove crop debris after harvest
- Halo blight: Treat seeds with antibiotics; plow bean debris deeply after harvest
- Damping-off: Sow seeds in warm, well-prepared soil; treat seeds with fungicide
- Mosaic: Plant virus-free seed; use resistant varieties
Sources
In addition to our General List of Sources (link), we used these specific references:
