Broccoli can be grown from seed, but it’s best to cultivate the seed in a seedling pot (or jiffy pot) rather than plant direct. If you don’t have the time or inclination to look after new seedlings properly, you may purchase established seedling from a garden supplier/nursery, from early Autumn to late Winter.
Like all vegetables, the brassica family prefer to be grown in full sun, in well-drained soil. Prior to planting, fork a little manure and potash through the soil. Plant at least 30cm apart. Broccoli is pretty forgiving and can be planted successfully in pots as well as garden beds. One per pot, and make it a large one.
Try to plant your seedling out by mid-Autumn to allow for early growth. A cold Winter means slow progress, and a late harvest. Brassicas are slow but steady growers. They get very green and leafy over the first two months and then almost overnight, start to develop the head/curd. At this stage your broccoli will be harvestable within 2-3 weeks