CANADA PLANTING GUIDE

Growing Broccoli in Canada — Spring + Fall Crops, Varieties & Cabbage Worm Defence

Why fall is the sweeter + easier crop in most Canadian gardens, best varieties for spring/fall/heat-tolerance/sprouting types, beating heat-bolt, cabbage worm + cabbage looper defence, the side-shoot continuous harvest, and overwintering Purple Sprouting Broccoli for March-April spears.

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Broccoli is one of the most-failed first-time Canadian crops — not because it's difficult, but because most gardeners try it as a spring crop when fall is dramatically easier. Spring broccoli faces a temperature-rising trajectory that pushes plants to bolt before heads form. Fall broccoli rides cooling autumn weather into tight dense sweet heads, plus a side-shoot harvest that often outweighs the main head. The trick is shifting your sowing date 6-8 weeks later than the seed packet usually suggests.

What follows is broccoli growing for actual Canadian conditions: spring-vs-fall strategy, variety selection by season, indoor + outdoor timing, beating heat-bolt and buttoning, the cabbage worm defence stack, main-head harvest + 4-8 week side-shoot harvest, overwintering Purple Sprouting Broccoli for the earliest fresh Canadian broccoli of the year, and the 5 most common Canadian broccoli problems.

Spring vs Fall — The Canadian Strategy

For most Canadian gardens, the fall crop is dramatically easier than the spring crop. The temperature trajectory is the entire reason.

Best Canadian Broccoli Varieties

Indoor Start + Transplant Dates by Canadian Region

Planting and Care

1. Soil prep: rich, well-drained, pH 6.0-7.5 (above 7.0 helps prevent club root). Heavy feeders — work in 5 cm of compost. See Composting in Canada.
2. Indoor start: sow 0.5-1 cm deep in cell trays or 7 cm pots, 4-6 weeks before transplant. Germinates 7-10 days at 18-21°C.
3. Wait for 4+ true leaves before transplanting — smaller transplants form premature buttons.
4. Spacing: 45-60 cm between plants, 75 cm between rows. Crowded plants form small heads.
5. Row cover from transplant — blocks cabbage worms, cabbage loopers, flea beetles, and cabbage root maggots all at once. Remove only briefly to weed.
6. Water: 2.5-4 cm per week, consistently. Stress = bolt + button. Drip or soaker preferred. See Watering in Canada.
7. Mulch: 5-7 cm of straw or shredded leaves once plants are 15 cm. Keeps soil cool + moist. See Mulching in Canada.
8. Feeding: side-dress with balanced 10-10-10 at 4 weeks; again at first head formation. Broccoli is one of the heaviest-feeding garden vegetables.

Cabbage Worm + Cabbage Looper Defence

Cabbage worms (small green caterpillars hatched from cabbage white butterfly eggs) and cabbage loopers (light green inchworms) are the top Canadian broccoli pests. Both eat holes through leaves and bore into developing heads.

• Row cover from transplant through harvest — the most effective control. Butterflies cannot reach the plants. Lightweight summer-weight cover.
• BTK (Bacillus thuringiensis kurstaki) — certified organic spray that kills caterpillars but is harmless to bees + other beneficial insects. Spray every 7-10 days during peak butterfly activity.
• Hand-pick visible worms daily; drop in soapy water. Check leaf undersides for clusters of small yellow eggs and crush.
• Companion planting — dill, sage, thyme, rosemary reportedly deter cabbage whites (deterrent, not control).
• Crop rotation — never plant brassicas (broccoli, cabbage, kale, Brussels sprouts, cauliflower) in the same bed two years running.

Harvest — Main Head Plus 4-8 Weeks of Side Shoots

Main head: cut when head is dense and dark green, before any yellow flowers open. Cut 15 cm down the stalk at a 45-degree angle (sheds rain + prevents stem rot). Don't pull the plant.

Side shoots: after the main head is cut, the plant continues to produce smaller heads from the leaf axils for 4-8 weeks. Total side-shoot yield often exceeds the main head. Cut each shoot when fist-sized or smaller. Best side-shoot producers: Calabrese, Belstar, Imperial, Aspabroc (which is all side-shoots).

Storage: 7-14 days fridge in perforated bag with damp paper towel. Freeze blanched (3 min boil, ice bath, freeze on tray) for year-round use. Don't store with apples, pears, or tomatoes (ethylene causes yellowing).

Purple Sprouting Broccoli — The Canadian Secret Weapon

Purple Sprouting Broccoli (PSB) is sown in summer, overwinters, and produces the earliest fresh broccoli of the year in March-April when supermarket broccoli is California-flown and mediocre. Available at farmers' markets for $8-12/lb if you can find it; home-grown is free.

• Where it works: Coastal BC (Victoria, Vancouver, Gulf Islands) most reliable. Maritimes (Halifax, Charlottetown) with light cloche. Southern Ontario lakeshore marginal. Prairie + interior Quebec: not viable without greenhouse.
• Method: sow indoors late May to mid-June. Transplant mid to late July with 60 cm spacing. Plants reach 90 cm by late October.
• Winter protection: 15 cm of straw mulch at the base after first hard frost. Plants stand through winter under snow or a row cover/cloche.
• Harvest: March through April for 4-6 weeks of pencil-thick purple spears. Each plant yields 30-50 spears total.
• Varieties: Santee (mid-spring), Apollo (early hybrid, Coastal BC favorite), Rudolph (late, can produce into May), Late Purple Sprouting (heirloom, hardiest).

Where to Buy Canadian Broccoli Seed

• West Coast Seeds (Delta, BC) — broad selection including PSB + Aspabroc.
• Veseys Seeds (Charlottetown, PEI) — ships nationally.
• William Dam Seeds (Dundas, ON) — Ontario standard.
• Salt Spring Seeds (BC) — heirloom + organic.
• Solana Seeds (Quebec) — specialty + heirloom (Romanesco specialist).
• Eagle Creek Farms (Bowden, AB) — Prairie-adapted short-season varieties.

5 Most Common Canadian Broccoli Problems

Related Canadian Guides