Vegetable
Curly Kale
Brassica oleracea var. sabellica · Brassicaceae
Also called: Scotch kale, Borecole, Curly-leaf kale
Curly Kale (Brassica oleracea var. sabellica) is a moderate-water vegetable well suited to Tucson and the low desert. It's a moderate-growing vegetable.
Curly Kale at a glance
- Water use
- Moderate (established)
- Sun
- Full sun in the cool season; tolerates partial shade. Late plantings benefit from afternoon shade as spring warms.
- Mature size
- 1-2 ft tall and 1-2 ft wide.
- Growth rate
- Moderate
- Bloom
- Yellow (4-petaled flowers if it bolts in spring; not the goal), Bolts/flowers in spring with heat - harvest leaves through the cool season before then.
- Cold hardiness
- Very cold-hardy cool-season biennial grown as an annual; tolerates Tucson frosts and light freezes well, and flavor often sweetens after frost. Declines and bolts once spring/summer heat arrives.
- Soil
- Fertile, well-drained soil rich in organic matter; pH 6.0-7.5.
- Native range
- Mediterranean / Western Europe (cultivated form of wild cabbage, Brassica oleracea)
- Best used as
- Nutritious cool-season leafy green (salads, sauteed, chips, smoothies), Long-harvest fall-through-spring crop, Ornamental edible (textured foliage), Raised-bed and large-container vegetable
- Wildlife
- Watch for cabbage loopers/aphids; flowers (if bolted) attract pollinators.
- Toxicity
- Non-toxic and edible for people. Note: like other brassicas, large quantities of raw kale can cause digestive upset or thyroid effects in pets (dogs/cats) - generally fine in small amounts but feed sparingly.
How to grow Curly Kale in Tucson & the low desert
Watering
Cool-season crop: set transplants or sow seed from September through January/February in Tucson; it grows through fall, winter, and into spring. Keep soil evenly moist with regular deep watering - even moisture keeps leaves tender and reduces bitterness and pest stress. Mulch to conserve moisture and moderate soil temperature.
Fertilizer & nutrients
Moderate-to-heavy nitrogen feeder. Amend with compost and side-dress with a nitrogen-rich fertilizer (or fish emulsion/blood meal) every 3-4 weeks for vigorous leafy growth.
Pruning & care
Harvest by picking lower/outer leaves first, letting the plant keep producing from the center ('cut-and-come-again'). Remove yellowed or pest-damaged leaves. No formal pruning needed.
Notes
One of the most productive and forgiving cool-season greens for Tucson - plant in fall for a long fall-through-spring harvest. Frost actually improves sweetness. Watch for aphids and cabbage worms; floating row cover helps. Not a summer crop.
Sources: University of Arizona Cooperative Extension / Pima County Master Gardeners cool-season vegetable calendar; Tucson Organic Gardeners Planting Guide; Green Things Nursery (Tucson) planting guide