Vegetable
Tomato
Solanum lycopersicum · Solanaceae
Also called: Garden tomato
Tomato (Solanum lycopersicum) is a moderate-water vegetable well suited to Tucson and the low desert. It thrives in full sun, with a fast growth rate.
Tomato at a glance
- Water use
- Moderate (established)
- Sun
- Full sun (6+ hours); benefits from afternoon shade cloth (30-40%) once Tucson temperatures climb above the mid-90s to protect fruit set and prevent sunscald.
- Mature size
- Determinate 2-4 ft; indeterminate 6+ ft with support.
- Growth rate
- Fast
- Bloom
- Yellow flowers; harvest red/orange/yellow fruit depending on variety, Two Tucson seasons: SPRING crop transplanted late February to mid-March for harvest before the June heat; FALL crop transplanted mid-August to September for harvest into fall/early winter. Fruit set stops when days exceed ~95F and nights stay above ~75F.
- Cold hardiness
- Frost-sensitive/tender annual; damaged below ~32F and stressed by both Tucson's hard frosts and extreme summer heat. Choose early-maturing (45-70 day) varieties for the short desert windows.
- Soil
- Rich, well-drained soil amended generously with compost; slightly acidic to neutral preferred but performs in amended alkaline desert soil with raised beds.
- Native range
- Native to western South America (Andes); domesticated in Mesoamerica. Not native to the Sonoran Desert.
- Best used as
- Edible fruit (culinary vegetable), Home/raised-bed vegetable gardening
- Wildlife
- Flowers attract bees (buzz pollination improves set); fruit can attract birds and rodents.
- Toxicity
- Fruit is edible; foliage, stems, and unripe green parts contain solanine/tomatine and are toxic to pets and humans if eaten in quantity.
How to grow Tomato in Tucson & the low desert
Watering
Keep soil evenly moist with deep, consistent drip irrigation; daily or near-daily in late spring/summer heat, less in cooler months. Inconsistent watering causes blossom-end rot and cracking; mulch heavily to stabilize soil moisture.
Fertilizer & nutrients
Feed with a balanced or slightly higher-phosphorus fertilizer at planting, then side-dress with nitrogen and potassium every 2-3 weeks once fruit sets. Avoid excess nitrogen, which yields foliage over fruit; calcium availability helps prevent blossom-end rot.
Pruning & care
Pinch suckers on indeterminate types and stake or cage; determinate varieties need little pruning. Remove lower leaves touching soil to reduce disease.
Notes
Grown as a warm-season annual in Tucson with two distinct planting windows around the summer heat. Select heat-setting and short-season varieties (e.g., Celebrity, Early Girl, heat-tolerant types) to beat the June-July heat that halts fruit set. Use shade cloth and consistent moisture; protect spring transplants from late frost.
Sources: University of Arizona Cooperative Extension - 'Growing Tomatoes' (extension.arizona.edu) and Pima County Monthly Gardening Guides (March-May); Pima County Master Gardeners; Tucson Organic Gardeners Planting Guide