Brassica oleracea var. italica 'Calabrese'
vegetableCalabrese is the classic Italian green broccoli, producing a large blue-green central head followed by a steady supply of smaller side shoots after the main head is cut. A cool-season brassica maturing in about 60 to 90 days, it is the standard home-garden broccoli, valued for the long secondary harvest that can continue for weeks.
Sun
full sun
Water
Every 3 days
Harvest
~65 days
Difficulty
medium
Lifecycle
biennial
Leaves year 1, flowers year 2
Spacing
18 in. apart
Planting Depth
1/4-1/2 in.
Soil pH
6.0-7.0
Soil Type
Firm, well-drained
Hardiness Zones
Zones 3 – 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
About 3 weeks after transplant, then every 3-4 weeks
Fertilizer
Nitrogen-rich (21-0-0 or fish emulsion)
Start seed indoors and transplant, or direct sow, timing the crop for cool weather in spring or fall, in full sun and fertile, moisture-retentive soil. Keep moisture even and feed for steady growth, since heat and stress cause the heads to open and flower prematurely; a fall crop maturing in cooling weather is usually the highest quality.
spring planting
Start seeds indoors
Mar 4
Transplant outdoors
Mar 25
Projected first harvest
May 29
fall planting
Start seeds indoors
Jun 30
Transplant outdoors
Aug 4
Projected first harvest
Oct 8
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
Cover with floating row cover from transplant to exclude the white cabbage butterfly; hand-pick green caterpillars; spray Bt if needed
Plant alyssum and dill to draw hoverflies and lacewings; blast colonies off with water
Row cover on young plants
Cut the central head while the buds are still tight and deep green, before any yellow flowers open, taking several inches of stem. Cutting the main head prompts the plant to produce smaller side shoots from the leaf axils, which can be picked every few days for several more weeks.
Broccoli is low in calories and very high in vitamins C and K, with folate, fiber, and sulforaphane, a glucosinolate-derived compound widely studied for its anticancer potential.
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