Vegetable
Leek
Allium ampeloprasum (Porrum Group) · Amaryllidaceae
Also called: Garden leek
Leek (Allium ampeloprasum (Porrum Group)) is a moderate-water vegetable well suited to Tucson and the low desert. It thrives in full sun.
Leek at a glance
- Water use
- Moderate (established)
- Sun
- Full sun (6+ hours); tolerates light afternoon shade in the low desert.
- Mature size
- Edible blanched shaft 6-12 in long, 1-2 in thick; plant 18-24 in tall, 6-10 in wide.
- Growth rate
- Slow (long-season crop, roughly 100-150 days to harvest from transplant).
- Bloom
- White to pale lilac (rarely flowered; harvested vegetatively), Harvest late winter to spring (Tucson). Flowers (globular umbel) only if overwintered into a second season; harvest before bolting.
- Cold hardiness
- Cool-season crop, frost-hardy to about 20 F; grown through Tucson winters and harvested before late-spring heat. USDA 9a-9b.
- Soil
- Deep, loose, well-drained loam rich in organic matter; amend Tucson's caliche/clay soils heavily with compost. pH 6.0-7.0; tolerates the region's alkaline soils.
- Native range
- Eastern Mediterranean and Western Asia (cultivated; wild ancestor circa Mediterranean basin)
- Best used as
- Edible vegetable (mild onion flavor), Cool-season raised-bed or kitchen garden, Companion planting (Allium scent deters some pests)
- Wildlife
- Flowers attract bees if allowed to bloom; the onion odor deters many browsing pests.
- Toxicity
- Toxic to dogs and cats (all Allium species cause Heinz-body hemolytic anemia in pets); safe and edible for humans.
How to grow Leek in Tucson & the low desert
Watering
Cool-season planting: sow seed/transplant Sep-Oct (also Jan-Feb) for harvest through winter into spring. Keep soil consistently moist; water deeply 1-2x/week, more as plants bulk up. Avoid letting the bed dry out, which causes tough, fibrous shafts.
Fertilizer & nutrients
Heavy feeder. Incorporate compost plus a balanced or nitrogen-rich fertilizer at planting, then side-dress with nitrogen (e.g., blood meal or ammonium sulfate) every 3-4 weeks to push leaf and shaft growth.
Pruning & care
No pruning. Blanch (whiten) the lower stem by hilling soil or mulch around the base, or by planting in a trench and back-filling as plants grow, to develop long tender white shafts.
Notes
A long-season cool-weather crop for Tucson: start in fall, hill the base for blanched white shafts, and harvest through winter and spring before summer heat. Mulch conserves moisture in the low desert. Not native; no landscape use.
Sources: University of Arizona Cooperative Extension - October Monthly Gardening Guide for Pima County (extension.arizona.edu); University of Arizona Cooperative Extension - Pima County Vegetable Planting and Harvesting Guide (extension.arizona.edu)