How to grow onions
Grow your onions using sets from Suttons. Sets are small, immature onions that are heat-treated before sale to prevent bolting (flowering) in the summer. Plant your sets in autumn or spring depending on the hardiness of the variety you choose.
Unpack your onion sets on arrival and store in a light, cool position until planting time. Plant your spring onion sets between February and April, leaving tips of bulbs above the soil surface, allowing about 10cm (4") between sets and about 30cm (12") between rows. 250g of onion sets (approx. 60 sets) will plant a row of about 6m (19'). Use plant protection to net your newly planted sets and prevent pesky pigeons from digging up the bulbs. Gently hoe around the developing onions to keep your patch weed-free.v
You can also grow your onions from seed. Sow your onion seeds in early to mid spring in a tray of fine seed compost. Place the tray in a sheltered place until germination happens and your seedlings are large enough to plant out into rows in the veg patch.
How long do onions take to grow?
Plant autumn planting onion sets in October and to be ready to harvest the following July. Onions need around four to five months to develop good sized bulbs from sets. More cold tolerant varieties like the red skinned onion ‘Electric’ and yellow onions ‘Senshyu’ happily overwinter in the garden when not much else is growing. Onion seeds take around four months to mature to a harvestable size.v
What are shallots?
Shallots are usually smaller and have a milder, sweeter flavour than onions. They are very closely related to each other, and are in the same plant family. Shallots can be multi-bulbed, smaller or longer and thinner than onions. They both grow in the same way and can be used in similar dishes, along with garlic bulbs.
How to plant shallots
Plant shallot sets in a sunny position into well drained, fertile soil. Push the sets into the soil, leaving the very top visible above the soil and around 10 cm between each set. Water in using a rosette to avoid disturbing the bulbs. Water every week during the growing season and more often in hot weather.
Grow shallots from seed by sowing under cover from January or outdoors from April. Sow seeds into seed trays of fine, damp compost or thinly along rows in the veggie patch. Keep your seedlings moist as they develop. The banana shallot ‘Zebrune’ has fantastic flavour grown from seed.