Growing Broccoli & Cauliflower from Seed


Growing Broccoli and Cauliflower from Seed

by Rob Sproule


Broccoli is one of the most vitamin rich vegetables we can grow.   They are overflowing with vitamin A and C, especially when eaten raw.   They take a little more care in growing than other veggies, but with some proper tips even beginners can  do it.


From Seed to Seedling

It’s a good idea to start broccoli from seed in early April to make sure it’s ready for harvest before the first hard frosts of fall.     Provide lots of light and keep it inside until the last frosts have passed.

If you’re the gambling type you can direct seed them in the garden in early/mid May.   Sow them thinly in a ½ inch through, 6 inches apart.   You’ll want to thin the seedlings until they are 3 inches apart, and as needed from there.


From Seedling to Harvest

It’s safe to plant your broccoli outside after, and here comes that dreaded statement, “all danger of frost has passed.”   If you do get a light freeze, throw some row cover over it and you should be okay.

Make sure your plants are about 3 inches high before transplanting outside, and mind their delicate root systems.   If you are planning for an edible container garden, then consider choosing a dwarf variety, like “˜Munchkin.’

Broccoli demand good quality, nutrient rich and robust soil.   If it’s depleted, or even if it’s not, top it up with compost, manure, or sea soil before planting.

Row cover is excellent for keeping off the dreaded cabbage moth, whose larvae regularly plague Alberta broccoli.   Worrying about pests is an inescapable part of the broccoli experience.


Harvest and Uses

The broccoli “˜head’ is really a tight cluster of flower buds.   Cut the stem with a sharp knife while they are still dark green (if they turn yellow you’ve waited too long) and while they are still in a compact cluster.

Once the main stem is cut, secondary stems should sprout out the sides, which are even tastier than the main stem.   Like peas, if you keep harvesting these it will keep producing them.

Broccoli is very versatile in the kitchen.   It freezes well and can be steamed, boiled, or eaten raw.  Raw broccoli retains the most vitamins (if you can get the kids to eat it).


Growing Cauliflower

Here’s the thing about cauliflower: while broccoli isn’t the easiest vegetable to grow, cauliflower are quite a bit more demanding.   It’s a bit of a prima-donna and needs conditions just so.   That being said, it’s full of nutrients and can be gorgeous in the garden.

When you think of cauliflower you’re probably thinking of the big white heads on the supermarket shelves.   Garden cauliflower is much more dynamic, with orange, purple, and green heads that are gorgeous in containers.

Sow cauliflower indoors 4-6 weeks before the last frost.   It’s a little more sensitive than broccoli so put it outside a week later.   Like broccoli, make sure to keep it covered with row cover to keep the greedy bugs off.

Cauliflowers are anti-social so make sure it’s not rubbing shoulders with other plants.   If you’re growing them in a container, I suggest that it has its own pot which is at least 25 cm deep, and choose dwarf varieties.

You will need firm, rich soil to grow it.   Cauliflower has a tantrum in poor soil and will reward you with tiny heads that aren’t worth the effort.   Make sure to keep it consistently moist because, you guessed it, it will have a tantrum if it dries out.

If you’re planting your broccoli or cauliflower in the garden, practice a 3-year rotation so that pests like moths can’t get established.   A spot where peas or beans grew the previous year is ideal.

Harvest them when the head is a creamy white colour.   If they tightly bunched head starts to fall apart, you’ve waited too long.


Read through our Growing Guides for tips to enrich your garden! 

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