Site Preparation: The site of where you grow your broccoli needs to be well dug and limed for a higher PH. This should ideally be done in the autumn on heavy soils but can be done as close as 6 weeks before planting out.The amount of lime will be specified on the packet and this instruction should be followed as damage to seedlings can occur if doses are exceeded.
Sowing: The seeds are small, hard, round balls which I spread over the surface of a seed tray filled with compost then cover the seed with a thin layer of compost. These seeds will normally germinate under cover between 7 and 14 days after sowing. Sow the seeds of broccoli at around the start of March with a second sowing a month later. In each batch sow 15 seeds and pick out only the strongest seedlings.
Planting Out: When planting out brassicas of all types the soil needs to be well dug but firm (The reason for this is that brassicas suffer from wind rock and don't form nice tight heads if disturbed by the wind). To help with wind rock the plants should be planted in a 2-3" deep furrow made along the row and then as the stalk increases in height follow it with soil built up and firmed in around the stalk.
Harvesting: When harvesting broccoli cut the stalk approx 1cm above the leaves, take care not to leave heads to long before cropping as they can soon go over. At the end of the season broccoli should be picked, split into smaller stems like you get in the shops (the smaller heads mean that it is easier to freeze quickly) blanched and put in the freezer for winter use.
Pests and Diseases: The number one pest of broccoli is the cabbage white butterflies caterpillars which will if left strip the crop in no time at all. The only worthwhile way of stopping these beasties is with netting. There are numerous methods that can be used including regular inspections, pesticides and homemade deterrent sprays (garlic etc.).
There are a number of other pests and diseases which do affect broccoli at various stages of growth. I have listed the remaining pests and the preventions I use:(This is not an exhaustive list but covers most bases)
- Slugs and Snails - Pellets
- Pigeons - Netting
- Root Fly - Mulch
- Club root - Liming
- Aphids - Insect spray
Varieties: The following are the varieties i have used with notes on the performance of each one.
- Samson - Good domed heads, excellent in the kitchen.