Vegetable
Brussels sprouts
Brassica oleracea var. gemmifera · Brassicaceae
Also called: Brussel sprouts
Brussels sprouts (Brassica oleracea var. gemmifera) is a moderate-water vegetable well suited to Tucson and the low desert. It thrives in full sun.
Brussels sprouts at a glance
- Water use
- Moderate (established)
- Sun
- Full sun (6+ hours).
- Mature size
- 24-36 in tall, 18-24 in wide.
- Growth rate
- Slow (about 90-110 days from transplant; the longest-season brassica).
- Bloom
- Yellow (only if it bolts; undesirable), Harvest mid-winter to spring in Tucson; must mature before late-spring heat causes loose, bitter sprouts.
- Cold hardiness
- Cool-season crop, frost-hardy to about 20-25 F; light frost actually sweetens the sprouts. One of the more challenging brassicas in the low desert because it needs a long cool spell. USDA 9a-9b.
- Soil
- Deep, fertile, well-drained loam high in organic matter; amend caliche/clay heavily with compost. pH 6.0-7.5; firm soil supports the tall stalk.
- Native range
- Cultivated form of wild cabbage native to coastal Western Europe; selected in Belgium
- Best used as
- Edible vegetable (roasted, steamed), Cool-season raised-bed crop
- Wildlife
- Aphids, cabbage loopers, and harlequin bugs are the main pests; floating row cover and timely sprays recommended in the low desert.
- Toxicity
- Non-toxic and edible for humans and pets.
How to grow Brussels sprouts in Tucson & the low desert
Watering
Long cool-season crop: per the Pima County guide, sow Aug-Sep, transplant Sep-Dec (S/T Oct, T Nov-Jan-Feb) for a winter-into-spring harvest. Water deeply and consistently 2x/week; even moisture is essential for tight, well-formed sprouts.
Fertilizer & nutrients
Heavy feeder. Incorporate compost plus a balanced fertilizer at planting, then side-dress with nitrogen every 3-4 weeks; steady feeding produces firm sprouts. Boron-deficient desert soils can cause hollow stems, a complete fertilizer with micronutrients helps.
Pruning & care
Remove yellowing lower leaves as sprouts form. Optionally top (remove the growing tip) about 3-4 weeks before harvest to push the sprouts to mature evenly. Harvest sprouts from the bottom up as they firm.
Notes
The trickiest of the common brassicas for Tucson: it needs a long, sustained cool season, so plant early (transplants by Oct-Nov) and harvest before spring heat. Light frost improves flavor. Not native.
Sources: University of Arizona Cooperative Extension - Pima County Vegetable Planting and Harvesting Guide, shows Brussels Sprouts T Jan-Feb, S Aug-Sep, S/T Oct, T Nov-Dec (extension.arizona.edu); University of Arizona Cooperative Extension - October Monthly Gardening Guide for Pima County (extension.arizona.edu)