BROCCOLI ‘Imperial’ Vegetable Seeds
Botanical Name: Brassica oleracea var. italica
- Heat-tolerant hybrid broccoli producing large, uniform dome-shaped heads.
- Reliable performer in warm Australian climates where other broccoli may struggle.
- Dense, fine-beaded crowns with firm structure—ideal for market growers and home gardens.
- High-yielding crop bred for consistency across seasons and variable weather.
- Rich in vitamins C and K plus dietary fibre for a nutritious boost.
- Versatile in the kitchen: perfect for steaming, roasting, stir-fries, or freezing.
Broccoli ‘Imperial’ is a premium hybrid variety valued for its strong heat tolerance, making it a top choice for growers in warmer regions of Australia. With its uniform blue-green heads and consistent yields, it is a reliable option for both commercial production and backyard harvests. For a detailed comparison of broccoli varieties—including those suited to cooler or sprouting types—see our Complete Guide to Growing Broccoli Varieties in Australia.
Plant Details
- Plant Type: Annual cool-season vegetable
- Mature Height: 60–80 cm
- Growth Habit: Compact, upright
Sowing Information
- Germination: 7–14 days
- Sowing Depth: 1–2 cm
- Position: Full sun to partial shade
- Sow Where: Directly in garden beds or raise in seed trays for transplanting
- Soil: Fertile, well-drained soil with pH 6.0–7.0; enrich with compost before planting
- Spacing: 45–60 cm between plants, rows 60–75 cm apart
Growing Tips
- Keep soil evenly moist to promote steady growth and tight, heavy crowns.
- Feed with a balanced fertiliser during vegetative growth, then side-dress with nitrogen as heads develop.
- Mulch to retain soil moisture, suppress weeds, and moderate temperature swings.
- Harvest promptly while heads are compact, before florets start to separate.
- Rotate with non-brassica crops to reduce soil-borne pests and diseases.
Harvest
Ready for harvest in approximately 65–80 days from transplanting. Cut heads when firm, heavy, and well-formed for peak quality.
When to Sow Broccoli ‘Imperial’ in Your Climate
| Climate Zone | Best Planting Time | Tips |
|---|---|---|
| Temperate | March–June, August–September | Sow early spring or late summer; provide water during warm spells. |
| Subtropical | March–May, August–September | Plant in cooler months; protect from excessive heat. |
| Tropical | Not recommended | Choose leafy brassicas more tolerant of tropical heat. |
| Cool | February–April, August–September | Protect seedlings from frost; sow early for autumn harvest. |
| Arid | March–May | Sow during cooler months; mulch heavily and water often. |
Companion Planting
Broccoli ‘Imperial’ benefits greatly from companion plants that boost growth, deter pests naturally, and improve overall garden health. Strategic planting creates a supportive ecosystem, maximising crop performance and flavour.
- Sage: An aromatic herb that repels cabbage moths, aphids and flea beetles. Sage’s scent masks broccoli, reducing pest attraction while encouraging beneficial insects and pollinators to the garden.
- Nasturtium: Acts as a trap crop, drawing aphids and whiteflies away from broccoli. Its low-growing habit shades soil, conserves moisture, and improves soil structure through natural nutrient cycling.
- Additional Companions: Chamomile, dill, onions, celery and marigold support pest control, enhance pollination and promote healthy, vigorous growth when planted alongside broccoli.
Using sage and nasturtium together with Broccoli ‘Imperial’ creates a productive, low-maintenance planting system. This combination improves soil fertility, reduces pest damage, and fosters steady, healthy development throughout the growing season, resulting in larger, more robust heads and a reliable harvest.
