How to Grow Onion Sets

Plant the onion sets 5–10cm (2–4in) apart, in rows 25–30cm (10–12in) apart, from mid-March to mid-April or in September. Gently push the sets into soft, well-prepared soil so the tip is just showing. Firm the soil around them and water well.

How long do onion sets take to grow?
How long do you soak onion sets before planting?
Do I need to soak onion sets before planting?
Is it better to grow onions from seed or sets?
What is the best time to plant onion sets?
What fertilizer is best for onions?
Do onions need full sun?
Why are my onions so small?
How deep do you plant an onion set?
Do onion sets need to be watered?

How long do onion sets take to grow?

Growing from onion sets saves time—40 to 60 days depending on variety; this is an important consideration if you live in a short-growing season region. Growing from both sets and seed in long-season regions allows for two harvests; one early in summer and the second in late summer and fall.

How long do you soak onion sets before planting?

The best thing to soak them in is compost tea. Put onion sets in compost tea and let set for 24 hours prior to planting. Drain and plant immediately. They will be well hydrated and need to be planted into garden soil quickly.

Do I need to soak onion sets before planting?

A set is an actual bulb and will produce onions quickly. You can plant onion sets without soaking them, but soaked onions will sprout more quickly. You can also soak onion seed before planting to encourage germination. Soaking the sets in compost tea will give them added nutrition and protection from disease.

Is it better to grow onions from seed or sets?

Onions can be purchased in a few forms: seed, sets or transplants. Growing from seed is unquestionably the most economical way to grow onions. It's also typically the only way to grow unique or unusual varieties. Seeds can be sown directly in the garden as soon as the soil can be worked in April or early May.

What is the best time to plant onion sets?

The best time to sow onion sets is mid March to mid April. If you are sowing red onion sets is better to leave them till April as they are more prone to bolting and a later planting may help. Sets can also be sown in Autumn from September to early October.

What fertilizer is best for onions?

Onions require a high source of nitrogen. A nitrogen-based fertilizer (ammonium sulfate or ammonium nitrate) should be applied at the rate of one cup per twenty feet of row. The first application should be about three weeks after planting and then continue with applications every 2 to 3 weeks.

Do onions need full sun?

Onions need full sun. Select a location where your onions won't be shaded by other plants. Onions need well-drained, loose and nitrogen-rich soil.

Why are my onions so small?

Growing the Wrong Onion Type

The most likely cause of small onions is growing the wrong type of onion in your climate zone. ... Seeds for short-day onions go into the ground in the fall. Short-day onions are always grown from seedlings or seeds, but long-day and indeterminate onions are grown from sets or seedlings.

How deep do you plant an onion set?

Plant sets in early spring as soon as the ground can be worked. Sets should be planted at a depth of 1 to 1 1/2 inches in rows 12 to 15 inches apart. For dry onions, plant the sets 2 to 3 inches apart. Sets grown for green onions can be planted closer together.

Do onion sets need to be watered?

Water if the weather is dry and give an occasional feed with a general liquid fertiliser. A light feed of sulphate of potash in June will help to ripen the bulbs ready for storage. Stop watering and feeding once the onions have swollen in mid-summer.