Vegetable / Cool season
Broccoli
A race against warm weather, with side shoots as the prize
Plant out byApr 6zone 6
- Family
- Cabbage (Brassicaceae)
- Sun
- Full sun (6+ h)
- Difficulty
- Fussy
- Days to harvest
- 50-85 days
- Spacing
- 18 in apart, rows 30 in
- Pot size
- 5 gal pot (fine in pots)
- Frost
- Half-hardy
- Start
- Start indoors
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Too late this year (try fall)
In zone 6, start seeds indoors Feb 23 to Mar 9; plant out Mar 30 to Apr 6; sow again for fall Aug 4 to Sep 1. Average last frost Apr 20, first fall frost Oct 20.
Units
Broccoli has a short fuse. Once the weather warms past about 75 degrees F, the tight green buds loosen and open into yellow flowers, sometimes within a couple of days. Dry soil does the same thing. So the whole plan is timing: get it growing in cool weather and cut before the heat catches up.
Most growers start seeds indoors 6 to 8 weeks before the last spring frost and set plants out 2 to 3 weeks before it. Seeds can also go straight in the ground at the same time, though they reach picking size later. Pick young transplants with four to six leaves. Big, root-bound seedlings often make a tiny early head the size of a quarter, a problem called buttoning. A cold snap right after planting can cause it too. Grown plants shrug off frost down to about 28 degrees F, which is why a fall crop is often the safer bet. Time fall plants so they mature in the cool weeks around your first frost.
Each plant takes up a good square foot or more and gives you one main head, usually 6 to 12 inches across. That sounds stingy for a small bed. The payoff comes after the first cut, when smaller shoots keep forming along the stem. Cabbage worms are the other daily chore. The green caterpillars match the florets so well that some end up in the steamer basket.
Things to consider
- Early varieties of about 50 to 55 days help where spring turns hot fast. A slower 65-day kind is a better fit for fall, when it can finish slowly in cool weather and short days.
- Packing plants closer than 12 inches gives smaller heads and fewer side shoots. Give each plant the full 18 inches if a long run of side shoots is what you want.
- Brown spots on the head can point to low boron. That is usually tied to high soil pH or dry spells, so a cheap soil test beats guessing at what is wrong with the plants.
Good neighbours
Keep apart
Pests to watch for
Cabbage wormsCabbage loopersAphidsFlea beetles
Questions about growing broccoli
When exactly do I cut the head?
Cut when the head is firm and the buds are still tight and green, before any yellow shows. Check every day once it starts forming, because a head left a few days too long goes loose fast. Morning is a good time to cut, while the head is cool and crisp, and the plant stays in the ground afterward.
Can broccoli grow in a pot?
Yes, one plant to a pot of about 5 gallons, ideally a compact or early variety. Pots dry out fast, and dry soil is a common trigger for early flowering, so check them daily in warm spells. Expect a smaller head than you would get in a bed, though the side shoots still come.
Should I pull the plant after the first cut?
Not yet: scatter a little nitrogen fertilizer about 6 inches from the stem and water it in well. Side shoots 3 to 6 inches long keep coming for several weeks. Pick them every few days before their buds open, and that second harvest can keep you in broccoli for weeks.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.