Brassica oleracea 'Purple Cape'
vegetablePurple Cape is an old heritage cauliflower, originally from the Cape region of South Africa, grown as an overwintering crop rather than a quick summer one. Its deep violet color comes from anthocyanins and the flavor is mild and slightly nutty. Plants are set out in mid to late summer, build a large leafy frame through fall, stand over winter where the climate is mild, and form their colorful domed heads in late winter and early spring when little else is ready. The purple fades toward green with long cooking, so it is best eaten raw or only lightly steamed to keep its striking color.
Sun
full sun
Water
Every 2 days
Harvest
~200 days
Difficulty
medium
Lifecycle
biennial
Leaves year 1, flowers year 2
Spacing
18-24 in. apart
Planting Depth
1/4 in.
Soil pH
6.5-7.0
Soil Type
Rich, well-draining
Hardiness Zones
Zones 7 – 10
Grown as an annual — this range is its winter hardiness, but you can grow it for a single season in any zone.
When to Fertilize
At transplant and again 4 weeks later
Fertilizer
High-nitrogen initially, then balanced
Grow Purple Cape as an overwintering cauliflower in regions with mild winters, roughly zone 7 and warmer. Start seed in early to mid summer, about June to July, and transplant into rich, firm, well-drained soil limed to a near-neutral pH to discourage clubroot, spacing plants 18 to 24 in. apart. Let the plants build a sturdy frame before cold sets in; they overwinter and then form heads in late winter to early spring. Keep evenly watered and net against cabbage worms. No blanching is needed, since the purple curds do not turn bitter in light and the color deepens in cool weather and full sun. In colder zones it cannot reliably survive winter outdoors and must be grown under cover, so it is far less dependable than a standard summer cauliflower.
spring planting
Start seeds indoors
Mar 4
Transplant outdoors
Apr 1
Projected first harvest
Oct 18
fall planting
Start seeds indoors
Jun 2
Transplant outdoors
Jul 7
Projected first harvest
Jan 23
Good neighbors that attract beneficial insects or deter pests
Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide
Row cover at planting; Bt (Bacillus thuringiensis) spray for organic control; hand-pick eggs
Rotate brassicas every 4 years; lime to pH above 6.8
Attract ladybugs and hoverflies; water spray for small colonies
Cut the heads in late winter or early spring once they are domed, compact, and fully purple, before the curds begin to separate. Harvest promptly, since heads pass their prime quickly as the weather warms. Steam or roast only briefly, and add raw to salads, because the purple pigments break down and fade with prolonged heat.
Combines cauliflower nutrient density (vitamin C, K, folate, sulforaphane) with anthocyanins from the purple pigment — a powerful antioxidant combination. Higher antioxidant capacity than white cauliflower.
For educational and informational purposes only — HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.
spring planting
fall planting