How to Grow Onions in the UK

Onions are a reliable and easy vegetable to grow in the UK. They don’t need much space, require little maintenance, and store well after harvesting.

Many beginners start with onion sets rather than seeds, which makes growing onions even simpler.

With a sunny spot and well-drained soil, onions usually grow without much difficulty.

When to plant onions

Onion sets are usually planted in March or April in most parts of the UK.

Some varieties can also be planted in autumn for an earlier harvest the following year.

Spring planting is usually easiest for beginners.

Onions grow best in:

They prefer:

Avoid very wet soil, which can cause onions to rot.

Onions grow best in loose soil with compost added beforehand.

They don’t need very rich soil, but good drainage is important.

Avoid planting onions in freshly manured soil, which can encourage too much leaf growth.

Onion sets are small bulbs that are planted directly into the soil.

To plant onion sets:

They will begin growing as the weather warms.

Onions need moderate watering while growing.

Keep soil:

Reduce watering once bulbs begin to swell and mature.

Too much water late in the season can affect storage.

Onions are usually trouble-free, but beginners sometimes notice:

Gently firm soil around bulbs if needed.

Onions are usually ready to harvest in late summer.

When leaves begin to turn yellow and fall over, bulbs are close to maturity.

Lift onions carefully and allow them to dry in a warm, airy place before storing.

Drying helps onions last longer.

Onions are one of the easiest vegetables to grow in the UK.

For best results:

They’re a great confidence-building crop for new gardeners.

You’re doing exactly the right thing now — building a repeatable set of plant guides.

You now have:

That’s a strong start.

laura tennantFebruary 9, 2026