All about growing Broccoli from seed

Purple broccoli on a wooden surface with a blurred green background

Growing Guide

Broccoli(stems) orCalabrese(heads), whichever you want to grow - we've got the seeds and guides to help you. Typcially a slow growing crop that thrives in cool temperatures, just watch out when the florets start to form they can go from being almost harvest ready to bolting in the blink of an eye. Sounds tricky, but if you time your harvests right you'll adore the taste.

Broccoli has its roots in the Mediterranean region, specifically in the areas now part of Greece, Turkey, and Italy. Like several of the other brassica family members, broccoli is believed to have originated from wild cabbage plants that grew in the region. As trade routes expanded during the Middle Ages, broccoli made its way to different parts of Europe. It was grown primarily in Italy and France, becoming an essential ingredient in local cuisine. Italian farmers developed new varieties, such as Calabrese broccoli, named after the Calabria region in Southern Italy.

Autumn Calabrese

Sow broccoli seeds in modules or seed trays indoors from March to May or in a well-prepared seed bed from June and July at a depth of 1cm and spaced 15cm apart. Transplant to their final positions around 5 weeks later when the seedlings have four or five leaves and when all chance of frost has passed.

When growing Broccoli, choose a sheltered position in firm, rich fertile, well drained soil in full sun. Prepare the soil in early spring by adding plenty of well rotted farmyard manure to the soil to improve its structure and fertility. Take care when transplanting Broccoli as it resents root disturbance.

Plant at a distance of 25cm apart, and cover with a protective netting or fleece to prevent attack from birds and insects. Water the plants thoroughly after planting. Broccoli thrives in moist soil, check the soil regularly and make sure it isn’t dry.

You can harvest the Broccoli heads, from August to November, when they’re tight and green, with a reasonable stalk. Cut at an angle, leaving the rest of the plant to encourage side growth which can then be harvested in the following weeks.

Height: to 60cm | Spread: to 60cm

Hardy annual | Full sun

Germination: 10 - 14 days

Harvest: From 11 weeks


Purple Sprouting (Winter)

In May sow thinly 6mm deep in a seed tray of good quality seed compost and lightly cover with a sprinkling of vermiculite. Place tray in a propagator until after germination. Transplant seedlings into 7.5cm pots and grow on until plants have 4-5 true leaves.

Alternatively, sow sprouting broccoli seeds in a well-prepared seed bed from June to July at a depth of 10mm and spaced 20cm apart. Transplant to their final positions around 5 weeks later when the seedlings have four or five leaves.

When growing purple sprouting broccoli, choose a sheltered position in firm, rich fertile, well drained soil in full sun. Prepare the soil in early spring by adding plenty of well rotted farmyard manure to the soil to improve its structure and fertility.

Plant purple sprouting broccoli deeply for stability at a distance of 60cm apart, and cover with a protective netting or fleece to prevent attack from birds and insects. Water the plants thoroughly after planting.

Harvest regularly, from November through to March, cutting the central spear with a sharp knife first as this encourages the side shoots to develop quickly.

Height: to 90cm | Spread: to 60cm

Hardy biennial | Full sun

Germination: 5 - 14 days

Harvest: From 25 weeks

Explore in store

Top Tip

Rotating crops can help prevent the buildup of pests and diseases in your garden. Avoid planting broccoli in the same location where cabbage, cauliflower, or other Brassica-family plants were grown in the past two years. 

Return to Growing GuidesManage your garden with the Sow & Grow App