PL. —Phaseolus vulgaris 'Black Turtle'Botanical illustration — drop image
Phaseolus vulgaris 'Black Turtle'

Black Turtle Bean

SpringSummerFall
3a10bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Black Turtle is the standard dry bean of Latin American cooking — small, glossy, and intensely flavoured once dried and cooked low and slow. It's a bush type that asks for almost nothing: no staking, no fussing, just warm soil and a bit of patience. Sow directly after last frost when the soil has genuinely warmed above 60°F; cold wet soil at germination is the main cause of failure.

You can harvest some pods early as shell beans (the seeds will be plump but not yet dry), but the main event is the dry harvest. Leave pods on the plant until they are papery and rattle when shaken — usually 85–100 days from sowing. Pull the entire plant and hang it upside down in a dry, airy space for two weeks to finish curing, then shell and store in an airtight jar. Well-dried beans keep for years. Like all beans, Black Turtle fixes atmospheric nitrogen through root nodules — turn the spent plants into the soil at season end rather than composting them.

Care guide
SunFull sun
WaterModerate; consistent moisture during flowering and pod fill; ease off as pods dry down
SoilAverage, well-draining; inoculate seeds with bean inoculant at sowing for best nitrogen fixation
Spacing4–6 inches (bush type)
Height18–24 inches
Zone3a – 10b
WinterAnnual — turn spent plants into the soil at season end.
Direct sow
Seasonal tasks
spring
sowSuccession sow — direct sow after last frost when soil is above 60°F; inoculate seed with bean inoculant before sowing; sow every 10 days through about 14 weeks before fall frost
summer
sowSuccession sow — direct sow after last frost when soil is above 60°F; inoculate seed with bean inoculant before sowing; sow every 10 days through about 14 weeks before fall frost
watchLast sow (~14 weeks before fall frost) — Black Turtle needs 85–100 days to dry maturity; anything after this won't finish before first frost
fall
watchPods papery and rattling — pull entire plants and hang upside down in a dry airy space for 2 weeks to finish curing before shelling
cutShell dried beans and store in an airtight jar; turn spent plant residue into the soil to return fixed nitrogen
Common problems

Bean Anthracnose

Symptoms

Dark, sunken brown-black lesions on pods, stems, and leaf veins; spots often have reddish or pinkish margins. Infected seeds carry the fungus.

Treatment

Plant certified disease-free seed and resistant varieties. Avoid working among wet plants. Remove and destroy infected debris and rotate out of beans for 2–3 years.

Halo Blight

Symptoms

Small water-soaked spots on leaves surrounded by a wide yellow-green halo; pods develop greasy, sunken lesions. Worse in cool, wet weather.

Treatment

Use clean seed and resistant cultivars. Avoid overhead watering and do not handle wet plants. Remove infected plants and rotate beans to a new area each year.

Mosaic virus

Symptoms

Yellowing, mottled, or distorted leaves. No cure — spread by aphids.

Treatment

Remove and destroy infected plants. Control aphid populations to prevent spread. Do not propagate from infected tubers.

Rust

Symptoms

Orange to brown raised pustules on the undersides of leaves, with yellow spotting on the upper surface. Heavy infections cause leaves to yellow and drop.

Treatment

Remove and destroy infected leaves. Avoid overhead watering and improve air circulation. Apply a sulfur or copper-based fungicide if it spreads. Clear plant debris in fall.

Pests

Aphids

Aphididae
Symptoms

Clusters of small soft insects on new growth and flower buds.

Treatment

Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.

Japanese Beetle

Popillia japonica
Symptoms

Adults skeletonize leaves and devour petals and buds; aggregations escalate rapidly. Grubs destroy turf in late summer and fall.

Treatment

Hand-pick adults in early morning into soapy water — beetles are sluggish when cool. Neem oil applied to foliage deters feeding but must be reapplied after rain. For grubs, apply milky spore (Bacillus popilliae) to turf — it takes 1–3 seasons to establish but provides long-term biological control. Beneficial nematodes (Heterorhabditis bacteriophora) applied in late August when grubs are young and near the surface offer faster results. Never use pheromone traps.