Autumn Planting Onions 'Red Baron' & 'Senshyu Yellow'

Where to Plant

Plant your Autumn Planting Onions ‘Red Baron’ & ‘Senshyu Yellow’ in an open, sunny position with fertile, moisture-retentive but well-drained soil. Before planting, remove weeds and improve the ground with well-rotted garden compost or other well-rotted organic matter if needed. Avoid fresh manure.

Good drainage is particularly important for autumn-planted onions, as sets can rot in heavy, waterlogged soil over winter. If your soil is very heavy and prone to winter waterlogging, a raised bed or large container may be a better option.

Onions prefer soil that isn't strongly acidic. If you know your soil is acidic, test its pH before adding garden lime and apply lime only if needed, ideally well ahead of planting.

Planting

Plant each set with the pointed end facing upwards, so the tip is just showing above the soil surface. Space the sets around 10–15cm apart, with around 30cm between rows, then gently firm the soil around them and water well.

When to Plant

Plant ‘Red Baron’ and ‘Senshyu Yellow’ in autumn, giving the sets time to establish roots before the coldest winter weather arrives. Growth will slow during colder weather before picking up again as temperatures rise in spring.

Growing in Containers

Both varieties can also be grown in large containers with good drainage. Fill with a good-quality peat-free compost, position in full sun and space the sets so the developing bulbs aren't crowded. Container-grown onions will need more regular watering than those growing in the ground.

Watering & Feeding

Onions have shallow roots, so don't let them become short of water while the bulbs are actively developing. Water during prolonged dry spells, giving the soil a thorough soak rather than frequent light watering.

Don't automatically stop watering as soon as the first tops begin to droop. If the bulbs are still actively swelling and the soil is dry, continuing to water for a little longer can help them fill out and produce plumper onions. Once the crop is reaching maturity and around half the tops have fallen naturally, stop watering so the bulbs can ripen and dry properly.

Well-prepared fertile soil should provide a good start. On poorer soils, autumn-planted onions can be given a suitable nitrogen-rich fertiliser in late winter. Avoid excessive nitrogen later in the season, which can encourage leafy growth at the expense of good bulb development.

Keep Them Weed Free

Onions don't compete well with weeds, so keep the ground around them clear throughout the growing season. Weed by hand close to the plants or hoe carefully between the rows to avoid damaging the shallow roots and developing bulbs.

Protecting Newly Planted Sets

Birds can sometimes pull newly planted sets from the soil before they've rooted properly. Check them regularly and gently push any disturbed sets back into place. Fleece or suitable netting can be used temporarily until the sets are securely rooted.

Watch for Bolting

Changes in temperature and other growing stresses can cause onions to bolt and produce a flower stem. Remove any flower stems as soon as they appear and use these onions first after harvesting, as bulbs from plants that have bolted won't store as well.

Good Companions

Onions are easy to fit into a mixed vegetable plot thanks to their upright growth. Grow them alongside crops such as beetroot, lettuce and other leafy salads, making sure neighbouring plants don't shade or crowd the developing bulbs.

Making the Most of Your Bed

Quick-growing crops such as radishes and salad leaves can be grown nearby and harvested while your onions are still developing. Just make sure the onions continue to receive plenty of light and aren't crowded as the bulbs swell.

Crop Rotation

Avoid growing onions where onions, garlic, leeks, shallots or other alliums have recently been grown. These crops can be affected by some of the same soil-borne pests and diseases, so rotate them around the vegetable plot rather than repeatedly using the same ground.

Planning Ahead

‘Senshyu Yellow’ can be lifted earlier, freeing up some growing space while ‘Red Baron’ continues towards maturity. Use cleared ground for later-sown salads, beetroot or other quick-growing vegetables.

When to Harvest

Don't expect both varieties to be ready together. ‘Senshyu Yellow’ is the earlier of the two and can provide your first golden onions from early summer. Allow ‘Red Baron’ to continue developing until its own foliage begins to yellow and fall naturally.

Don't Bend the Tops Over

There's no need to bend the foliage over by hand to encourage the bulbs to ripen. Let the leaves yellow and fall naturally, then harvest each variety as it reaches maturity.

How to Harvest

Choose a dry day and carefully loosen the soil beneath each bulb with a garden fork. Lift the onions gently to avoid bruising or damaging them, as damaged bulbs are more likely to rot and should be used first.

Drying Your Onions

Spread freshly lifted onions out somewhere dry with plenty of air circulation, keeping the foliage attached while they cure. In suitable weather they can dry outdoors; if conditions are damp, move them into a greenhouse or well-ventilated shed. Wait until the necks and outer skins are thoroughly dry before preparing them for storage.

Storing Your Harvest

‘Red Baron’ has excellent keeping qualities and is the better choice of the two for longer storage. Cure the bulbs thoroughly and store only sound, fully dried onions somewhere cool, dry and well ventilated. ‘Senshyu Yellow’ is grown primarily for its earlier harvest rather than exceptionally long storage, so enjoy these bulbs first.

Top Tip

Think of the two varieties as a succession rather than one crop to lift together: enjoy ‘Senshyu Yellow’ first, then harvest ‘Red Baron’ as it reaches maturity and put your best cured red bulbs aside for later.

Two Onions, Two Flavours

This duo gives you more than a choice of colour. ‘Senshyu Yellow’ has a mild, sweet flavour, while ‘Red Baron’ has a richer, fuller flavour and distinctive red-ringed flesh.

Enjoy ‘Senshyu Yellow’ First

Make the most of the earlier ‘Senshyu Yellow’ harvest in salads, sandwiches and everyday cooking, or roast the golden bulbs until soft and sweet. Young onions can also be lifted and enjoyed before they reach full size.

Make the Most of ‘Red Baron’

Slice ‘Red Baron’ into salads, burgers and salsas when you want its deep colour to stand out, or add it to soups, sauces, curries and casseroles. Cooking softens its fuller flavour and brings out its natural sweetness.

Fresh Now, Store for Later

The different qualities of these two onions help extend the usefulness of your harvest. Enjoy the earlier ‘Senshyu Yellow’ crop first, then properly cure your best ‘Red Baron’ bulbs and keep them for later.

Top Tip

Use smaller bulbs whole or halved for roasting, and save larger onions for slicing and chopping. Keeping the two varieties separate after harvest also makes it easier to use ‘Senshyu Yellow’ first and choose the best ‘Red Baron’ bulbs for storage.

What to Expect When They Arrive
Your onions are supplied as dormant sets in a netted bag, ready for planting. Sets are sold by weight, so the number of individual bulbs you receive may vary slightly from the approximate count shown on our website.

Ready to Plant
Your onion sets can be planted out as soon as they arrive. Each small bulb will establish roots and grow on to produce a mature onion ready for harvesting.

If You Can't Plant Straight Away
Remove the sets from their delivery packaging and keep them in their netted bag somewhere cool, dry and well ventilated until you're ready to plant. Check them occasionally and plant as soon as conditions allow.