Pre-rooted Onion ‘Karmen’ (Spring Planting)

Where to Plant

Choose an open, sunny position with fertile, well-drained soil. Before planting, remove weeds and work in well-rotted garden compost if needed. Avoid freshly manured ground and areas that remain waterlogged, as onions develop best where excess water can drain away freely.

Planting Your Pre-rooted Onions

Carefully separate the pre-rooted sets, taking care not to damage the developing roots. Plant them around 10cm apart, with approximately 30cm between rows. Position each set so the roots are below soil level and the growing tip remains above the surface, then firm the soil gently around it and water after planting.

Growing in Containers

Choose a large container with good drainage and space the plants around 10cm apart. Container-grown onions will need more regular watering than those growing in open ground.

Watering & Feeding

Keep newly planted onions adequately watered while they establish, then water during prolonged dry spells, particularly while the bulbs are developing and swelling. Once the bulbs are approaching maturity and the foliage begins to yellow and die back, stop watering to allow them to ripen.

Well-prepared soil should provide a good start. On poorer soils, a balanced vegetable feed can be applied while the plants are actively growing. Avoid excessive high-nitrogen feeding, which can encourage leafy growth at the expense of bulb development.

Keep Them Weed Free

Onions have relatively shallow roots and don't compete well with weeds. Weed regularly, taking care not to disturb the roots or developing bulbs.

Why Heat Prepared?

These sets have been heat prepared for 20 weeks to reduce the risk of bolting. Bolting is when an onion prematurely produces a flower stem, diverting energy away from bulb development.

Good Companions

Onions fit easily into a productive vegetable plot alongside crops such as carrots, beetroot and leafy salads. Their upright growth takes up relatively little room above ground, helping you make good use of your growing space.

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. Avoid overcrowding the plants so they continue to receive plenty of light and good airflow.

Crop Rotation

Avoid planting onions where onions, shallots, garlic or leeks have recently been grown. These crops belong to the same family and can be affected by some of the same soil-borne pests and diseases.

Planning Ahead

Where practical, leave three to four years before growing onion-family crops in the same ground again. Once your onions have been harvested, the cleared space can be used for later-sown salads and other quick-growing vegetables.

When to Harvest

Your onions are approaching maturity when the foliage begins to yellow and naturally fall over. There's no need to bend the foliage over yourself.

How to Harvest

Choose a dry day and carefully loosen the soil beneath the bulbs with a garden fork before lifting them. Handle the onions gently, particularly those you intend to store, as bruising and damage can affect their keeping quality.

Drying Your Harvest

Allow the bulbs to dry thoroughly somewhere warm, dry and airy before storing. In fine weather they can begin drying outdoors; if conditions are damp, move them under cover somewhere with plenty of ventilation.

Sorting Your Crop

Once thoroughly dry, check the bulbs and set aside any that are damaged, soft or showing signs of deterioration. Use these first and keep only sound, well-cured onions for longer-term storage.

Top Tip

If any plants produce a flower stem, harvest and use those bulbs first rather than putting them into storage. Heat preparation reduces the risk of bolting but doesn't eliminate it completely.

Made for Salads

‘Karmen’ has crisp flesh and an exceptionally sweet flavour, making it an excellent red onion for eating raw. Slice it into salads, sandwiches and burgers where you can also show off the attractive crimson rings.

Just as Good Cooked

Its sweetness works well when the bulbs are roasted or fried, while chopped ‘Karmen’ can be used in sauces, curries, casseroles and plenty of other everyday dishes.

Make the Most of Your Harvest

Use any damaged bulbs first and put your best, thoroughly dried onions aside for storing. That way you can enjoy your crop over a longer period rather than using everything at harvest time.

What to Expect When They Arrive

Your pack contains 12 pre-rooted ‘Karmen’ onion sets. Unlike traditional dormant sets, the growing process has already been started for you, so the onions arrive with developing roots and many may also have visible green shoots. Some will naturally be further into growth than others.

When Your Onions Arrive

Remove the sets from their packaging as soon as possible and check them over. If the roots appear dry, moisten them before planting. Carefully separate the sets if needed, taking care of the developing roots, and plant them into their final position as soon as conditions allow.

Don't Worry About a Few Damaged Roots

Handle the roots carefully, but don't worry if a few are damaged while the sets are being separated or planted. The onions will produce new roots as they establish in the soil.

If You Can't Plant Straight Away

Keep the sets somewhere cool, bright and sheltered until you can plant them. Don't allow the developing roots to dry out, and get them into their final position as soon as possible.