Monty Don shares the one crop to sow now for summer harvest

Monty Don, star of Gardeners’ World, has revealed which crop you should be sowing now for bountiful harvests in summer.

Speaking to the Daily Mailhe commented that to give onions the longest possible growing season, he sows them as early as January.

“This means they’ll need the protection of a greenhouse or cold-frame for another few months, and then a period of hardening off before they can be planted out,” he said.

“But I take huge encouragement from the fact that I’m creating new life in the depths of winter – with the promise of a summer harvest.”

Alternatively, gardeners can wait until the last frost to sow their onions, with more developed shop-bought bulbs.

Onions are a versatile and hardy crop to grow and have long been a favorite of gardeners. Frequently used in the kitchen and straight forward to grow, with good storage they can last year round.


How to grow onions

There are two ways to grow onions, either you start with sets or seeds.

Sets are bulbs, which take around 20 weeks to mature from planting. Seeds take four weeks longer, require earlier sowing and therefore need a greenhouse or another sheltered area to survive the first growing stages.

Onions can be sown outside in September and October to overwinter, then March and April in spring.

However, you can plan as early as January if, like Monty Don, they will be indoors.


Before planting, make sure your soil is fine and “soft enough to stick a finger in as far as the knuckle without any soil sticking to it,” according to Don.

The soil also needs to be fairly well draining and in full sun.

Onion sets ideally should be 10-15cm apart, allowing 30cm between rows. They should be planted just below the soil surfacewith just the bulb tips showing.

Meanwhile, seeds should be sown in a tray 1cm apart and when seedlings become around a few inches tall, prick them out into fresh compost.

Once mature, they are ready to be planted in the garden.


Onions are simple to care for. Make sure you do not let their soil dry out and feed with a nitrogen rich fertiliser every fortnight, a month after planting.

You may have to occasionally weed the area around onions as they do not react well to competition for water and light.

This can even be a problem when onions are competing between themselves. That is why space is so important when planting.


You can harvest your onions at whatever size you like. If you want to wait until they have reached their maximum size, look for their foliage to droop and turn brown.

To harvest them, gently loosen the soil underneath the onions and lift.

Remove any soil and let them dry on a rack or on newspaper. Once the outside skin is crispy, the onions are ready for storage.

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