Vegetable
Black-eyed pea (cowpea)
Vigna unguiculata · Fabaceae
Also called: Cowpea, Southern pea, Crowder pea, Field pea, Black-eyed bean, Yardlong bean (subsp. sesquipedalis)
Black-eyed pea (cowpea) (Vigna unguiculata) is a low-water vegetable well suited to Tucson and the low desert. It thrives in full sun, with a fast growth rate.
Black-eyed pea (cowpea) at a glance
- Water use
- Low (established)
- Sun
- Full sun (6-8+ hours); one of the most heat-loving, sun-tolerant vegetables and thrives in full Tucson summer sun where other crops struggle.
- Mature size
- Bush types 1-3 ft; vining/yardlong types climb 6-10+ ft. Pods 6-10 in (yardlong much longer).
- Growth rate
- Fast
- Bloom
- Pale yellow to white, sometimes with violet/purple tinge, Flowers ~6-8 weeks after sowing; harvest green snaps ~60 days, shelling/dry peas ~75-90 days. In Tucson, sow in late spring/early summer for mid-to-late summer and fall harvest (a classic monsoon-season crop).
- Cold hardiness
- Frost sensitive warm-season annual but extremely heat- and drought-tolerant; ideal for USDA 9a-9b summer. Killed by frost.
- Soil
- Tolerant of poor, sandy, and alkaline desert soils; prefers well-drained soil, pH 5.5-7.5. As a legume it fixes nitrogen and improves soil.
- Native range
- Sub-Saharan Africa (domesticated cowpea). Not native to the Sonoran Desert, but exceptionally heat- and drought-adapted and long grown in the desert Southwest.
- Best used as
- Fresh shelling peas / dry peas, Green snap pods (young), Home vegetable garden, Nitrogen-fixing cover crop / green manure, Livestock forage
- Wildlife
- Flowers attract bees and other pollinators; foliage supports beneficial insects. Provides forage/seed for wildlife; can attract aphids.
- Toxicity
- Cooked peas non-toxic and a nutritious staple. As with other legumes, eat cooked (raw/undercooked legumes can cause GI upset); generally safe and a traditional desert food crop.
How to grow Black-eyed pea (cowpea) in Tucson & the low desert
Watering
Drought-tolerant once established; water deeply but infrequently (about weekly, more during flowering/pod set and peak heat). Tolerates Tucson summer heat and can be grown through the monsoon. Avoid overwatering, which favors foliage and disease.
Fertilizer & nutrients
Very low fertilizer needs; fixes its own nitrogen via Rhizobium. Avoid nitrogen fertilizer (causes excess vine, fewer pods); a little phosphorus/potassium or compost is sufficient. Often grown as a soil-building cover/green-manure crop.
Pruning & care
No pruning needed; bush and vining (yardlong) forms exist. Vining types benefit from a trellis. Harvest regularly for continued production.
Notes
One of the best-adapted hot-season crops for Tucson, tolerating heat and drought that stress beans. Direct sow once soil is warm and frost is past, from April through July (excellent monsoon planting). Inoculate seed in new beds for best nitrogen fixation. Heirloom/desert-adapted cowpeas (e.g., tepary-region Southern peas) are especially tough. Great for soil improvement and summer production when little else thrives.
Sources: University of Arizona Cooperative Extension (Pima County) vegetable planting calendar; Pima County Master Gardeners; Native Seeds/SEARCH desert-adapted legume guidance; Arizona low-desert legume/cover-crop guidance