Growing broccoli

Broccoli is a healthy cool season vegetable that is high in vitamins A, C, Folic acid and calcium and a valuable vegetable to grow in the home garden.

Harvesting broccoli

Growth habit and planting needs

Sow your seeds in September in seedling trays to plant out in October November for a summer harvest , or in February, then planting out the seedlings in March and April for a winter harvest.

You can make your own seed raising mix using this formula:

1/3  river sand

1/3 coconut fibre (coir)

1/3 vermiculite

plus 1tbsp garden lime per bucketful of the above mix

Plant the seeds into the seedling trays, sowing them 5mm deep and keep the mix consistently moist. They will germinate within 4-7 days. When they are about 5 cm tall carefully transplant into small pots and keep growing in a well lit position to prevent the seedlings from becoming leggy.

Transplant the seedlings in late summer when they have 4-5 true leaves, watering the bed thoroughly before setting the seedlings into the soil.

Preparation of the garden bed is very important to the successful growing of the broccoli and should be started 4 -6 weeks ahead of planting. Ideally they should follow a legume crop in the crop rotation cycle to ensure that there is enough nitrogen naturally available in the soil. Broccoli are heavy feeders and prefer a fertile, well drained soil that is high in organic matter. Dig over the soil well and add some well rotted compost and some composted poultry manure. Broccoli like the soil to be slightly acidic with a pH of 6.0-7.5 so test the soil and correct if needed.

broccoli plantsThe fully matured broccoli plant can grow to a height of 90cm with a spread of 60cm so it is important to space them well. Space the seedlings 30-60cm apart.

Once planted out into the garden it is vital that the plants be consistently well watered. Broccoli are shallow rooted plants and so their surroundings need to be kept free of weeds and well mulched to conserve moisture around the roots. Once growing they must be kept continuously moist.


The first harvest will be the central head which should be cut cleanly at an angle to ensure that the stem is not cracked and that water will run off the cutting site to prevent rotting. Make sure to leave the leaves on the stem as as new shoots will appear in the leaf axils.

This broccoli was planted surrounded by a bed of parsley and was untouched by pests. It shows the benefit of companion planting to protect vegetables from garden pests.

Head of broccoli

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