Vegetable · Sonoran native
Tepary Bean
Phaseolus acutifolius · Fabaceae
Also called: Tepary, Pavi, Bavi
Tepary Bean (Phaseolus acutifolius) is a very low-water vegetable native to the Sonoran Desert region well suited to Tucson and the low desert. It thrives in full sun. Expect white to pale lavender blooms mid-to-late summer.
Tepary Bean at a glance
- Water use
- Very Low (established)
- Sun
- Full sun (6+ hours); thrives in intense low-desert summer heat.
- Mature size
- Bushy to semi-vining annual, roughly 1-2 ft tall with vines trailing 2-4 ft.
- Growth rate
- Fast; one of the quickest-maturing beans, about 60-90 days from sowing to dry harvest.
- Bloom
- White to pale lavender, Flowers mid-to-late summer (white to lavender), with dry pods ready early to mid-fall.
- Cold hardiness
- Frost sensitive (a warm-season annual); killed by frost but matures fast enough to finish before fall frost in USDA 9a-9b.
- Soil
- Tolerates poor, alkaline, sandy or rocky native desert soils; needs good drainage. No need for rich soil.
- Native range
- Sonoran Desert of Arizona and northern Mexico; domesticated by the Tohono O'odham. One of the few crop plants truly native to the low desert.
- Best used as
- Edible dry bean (high protein, drought-hardy staple), Heritage/Native foods garden, Nitrogen-fixing cover crop, Low-water summer vegetable
- Wildlife
- Flowers attract pollinators; foliage and seed can be browsed by rabbits and rodents.
- Toxicity
- Non-toxic when cooked. Like all common beans, raw/undercooked dry beans contain lectins and should be cooked before eating by people or pets.
How to grow Tepary Bean in Tucson & the low desert
Watering
MONSOON CROP: traditionally direct-sown at the start of the summer monsoon, mid-June to mid-July, in spots that catch storm runoff. Needs moist soil to germinate, then is extremely drought tolerant; water deeply only if monsoon rains are sparse. Overwatering reduces yield.
Fertilizer & nutrients
Minimal needs. As a legume it fixes its own nitrogen (inoculate seed with rhizobia in new ground); avoid high-nitrogen fertilizer, which promotes foliage over pods. A little compost at planting is plenty.
Pruning & care
None. Harvest whole plants once pods dry on the vine, then thresh for dry beans.
Notes
The most drought- and heat-adapted bean in the world and a true Sonoran Desert native; flowers can set seed above 105 F. Ideal Tucson monsoon crop, planted to exploit summer rains. Seed available from Native Seeds/SEARCH (Tucson). Brown, white, and other landrace types exist.
Sources: University of Arizona Cooperative Extension / Pima County Master Gardeners; Native Seeds/SEARCH (Tucson); USDA NRCS Plant Guide: Phaseolus acutifolius; Arizona-Sonora Desert Museum