Best Buy onions

Onions give a good return on garden space, and you can store them right through to spring, so you always have them at hand.

Onion sets (small bulbs) are the easiest way to grow onions and to help you choose which of the many varieties to grow, the Which? Gardening team has trialled 12 different varieties, looking at yield, bulb quality and whether they bolted before harvest.

Only logged-in Which? members can view our recommendations in the table below. Not a member? Join Which? to get instant access to all our reviews.

The best onions
What it looks like	Onion variety	Yield from 30 sets
	A Best Buy in our last trial, this showed its quality again. The untreated sets were planted in early March and were ready to harvest by the end of July. No bulbs bolted or rotted. Most were in the useful 6-8cm-diameter size range and were firm with good skins. Find out which onion variety we're talking about - log in or join Which?
	These sets, which had not been heat treated, were planted two weeks after one of the other Best Buys and matured a week later. Otherwise they were similar in all respects, apart from being a slightly darker brown. The quality of the bulbs was excellent. Find out which onion variety we're talking about - log in or join Which?
	These heat-treated sets were the last to mature, in early August. We only harvested 21 bulbs from this plot, but they were big: two thirds were 6-8cm in diameter or larger, with an average weight of 144g. None had bolted or rotted. They were firm, and a good, strong red colour inside. Find out which onion variety we're talking about - log in or join Which?
	The yield and bulb quality were as good as our other two Best Buy brown onions from sets, so we have no hesitation in recommending this. These sets had not been heat treated and were planted in early March. Find out which onion variety we're talking about - log in or join Which?
	Like most red onions, these sets were heat treated and therefore planted a bit later, at the end of March. However, this variety matured at the same time as the others. All the bulbs were useable, very firm and had good skins. Over half of them were 6-8cm in diameter. Find out which onion variety we're talking about - log in or join Which?

How Which? trials onions

To trial onions, we planted 12 varieties of onion sets in March in 3m-long rows and assessed 30 bulbs of each. We noted which varieties bolted (produced a flower stalk and became unusable) and recorded the size range, weight and quality of the bulbs.