How to Grow Calabrese Broccoli
Brassica oleracea var. italica 'Calabrese'
Calabrese broccoli is a reliable cool-season brassica prized for its tender florets and mild flavor. Gardeners grow this heirloom variety to enjoy fresh harvests well into late summer or early fall, tolerating light frosts that many other crops cannot withstand.
Starting Calabrese Broccoli: indoors or direct sow?
🏠 Start indoors 4 weeks before your last spring frost, then move the seedlings outside.
You can start seeds indoors four weeks before the last frost or sow directly outdoors during that same window.
Soil, care & harvest
Prepare loose, fertile soil with a pH between 6.0 and 7.0 for best results. Sow seeds directly outdoors two to six weeks before your last spring frost date, as this cool-season crop thrives in cooler weather. Plant seeds about one inch deep; they typically sprout within five to ten days once conditions are right.
Space plants twelve to eighteen inches apart to ensure proper air circulation and head formation. Provide consistent moisture, aiming for one to one-and-a-half inches of water weekly, keeping the soil evenly damp but not soggy. Apply a layer of mulch around the base to retain moisture and suppress weeds while feeding with balanced fertilizer if growth seems slow.
Watch for cabbage worms, aphids, flea beetles, and loopers; use row covers or hand-pick pests early to prevent damage. Keep an eye out for clubroot, black rot, downy mildew, and bacterial soft rot by ensuring good air flow. Harvest the main head when it is firm and tight, usually sixty to ninety days after sowing.
When to Plant Calabrese Broccoli
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | April – May | June – July | August – September |
| Zone 2 | April – May | May – July | August – September |
| Zone 3 | March – April | May – June | July – October |
| Zone 4 | March – April | April – June | July – October |
| Zone 5 | February – March | April – May | June – November |
| Zone 6 | February – March | April – May | June – November |
| Zone 7 | February – March | March – May | June – November |
| Zone 8 | January – February | March – April | May – December |
| Zone 9 | January | February – March | April – December |
| Zone 10 | January | January – March | April – December |
| Zone 11 | January | January – February | March – December |
| Zone 12 | January | January – February | March – December |
| Zone 13 | January | January – February | March – December |
Companion Plants for Calabrese Broccoli
✓ Good companions
Repels aphids and whiteflies, may improve flavor
Attracts beneficial wasps that parasitize cabbage worms
Grows well in broccoli's shade, efficient space usage
Deters cabbage worms, aphids, and other brassica pests
Acts as trap crop for aphids and cabbage worms
Repels cabbage root fly and aphids with strong scent
Repels cabbage moths and other brassica pests
Compatible root systems, similar growing conditions
✗ Keep away from
Same family, attracts similar pests and diseases
Both are heavy feeders competing for same nutrients
Competes for nutrients and may stunt broccoli growth
Nutrition Facts
Per 100g serving (USDA FoodData Central)
