Vegetable
Bush bean
Phaseolus vulgaris · Fabaceae
Also called: Snap bean, Green bean, String bean, Common bean, Bush snap bean
Bush bean (Phaseolus vulgaris) is a moderate-water vegetable well suited to Tucson and the low desert. It thrives in full sun, with a fast growth rate.
Bush bean at a glance
- Water use
- Moderate (established)
- Sun
- Full sun (6+ hours); afternoon shade or shade cloth helps during the hottest part of Tucson summer to prevent blossom drop.
- Mature size
- Compact bushy plants 1-2 ft tall and wide; pods 4-7 in.
- Growth rate
- Fast
- Bloom
- White (sometimes pale pink or lavender depending on cultivar), Flowers ~4-6 weeks after sowing; snap beans harvest ~50-60 days from seed. In Tucson, spring crop harvests May-June and fall crop October-November.
- Cold hardiness
- Frost sensitive warm-season annual; killed by frost and damaged by cold. Grows in USDA 9a-9b in frost-free windows.
- Soil
- Well-drained loam with compost; tolerates alkaline desert soil, prefers pH 6.0-7.0. As a legume it fixes its own nitrogen with Rhizobium bacteria.
- Native range
- Mesoamerica / Central and South America (domesticated common bean). Not native to the Sonoran Desert (the wild Sonoran tepary bean, Phaseolus acutifolius, is the desert-native relative, not this species).
- Best used as
- Fresh eating (snap/green beans), Dry beans (if left to mature), Home vegetable garden, Nitrogen-fixing rotation crop
- Wildlife
- Flowers are largely self-pollinating but visited by bees; foliage can attract aphids and bean beetles.
- Toxicity
- Cooked beans non-toxic and safe. Raw/undercooked common beans contain lectins (phytohaemagglutinin) that can cause GI upset in people and pets, and are toxic to dogs raw, so cook before eating; keep raw beans away from pets.
How to grow Bush bean in Tucson & the low desert
Watering
Keep soil evenly moist, especially during flowering and pod set; water deeply 2-3x/week (more in peak heat). Avoid drought stress at bloom (causes blossom drop) and avoid waterlogging. Drip irrigation and mulch recommended; avoid wetting foliage.
Fertilizer & nutrients
Low nitrogen needs because beans fix nitrogen; amend with compost and a little phosphorus/potassium. Excess nitrogen produces foliage at the expense of pods. An inoculant can help in new beds.
Pruning & care
No pruning needed; bush types are self-supporting and compact (no trellis required, unlike pole beans). Harvest regularly to keep plants producing.
Notes
Tucson has two warm-season windows: spring direct-sow mid-February through April (after frost), and a fall sow late July through early September. Avoid sowing into peak June-July heat, which causes blossom drop and poor pod set. Provide afternoon shade in extreme heat, mulch, and steady moisture. Easy, fast, productive home crop. Choose heat-tolerant cultivars (e.g., 'Contender', 'Provider').
Sources: University of Arizona Cooperative Extension (Pima County) vegetable planting calendar; Pima County Master Gardeners; Arizona low-desert legume guidance