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Onion Sets Collection (Heat Prepared)

  • Catalogue Code 1040-6017
  • Pack Contents: 1 complete collection

This fantastic heat prepared Onion Collection has been specifically heat-treated for 20 weeks to minimise bolting. Heat preparation will also extend the growth period of the onions so that much greater yields can be achieved. 

Our Heat Prepared Collection includes 1 pack each of:

Marshalls Fen Early  - A truly superb onion which produces one of the earliest crops from a spring planting.The bulbs will keep much better than other early types – right through until the end of winter. The sets have undergone a partial heat preparation to improve performance and prevent bolting.

Marshalls Red Fen - A clear winner in our trials, Red Fen’s performance was excellent. It has a round shape and a deep-red colour with a good flavour. It stores well and because it is heat prepared is more resistant to bolting

Rumba - A top performing main crop variety that’s ideally suited to growing in the UK. It produces high yields of large, uniform, round onions with a sweet flavour, making it ideal for eating raw in salads as well as cooking. Good thick skin and quality flesh makes this a good variety for long-term storing.

Sets will be released from the preparation rooms just as soon as they are ready for planting.


  • Will flower well in full sun
  • Will flower well in partial sun

Growing Calendar for Onion Sets Collection (Heat Prepared)

  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
Sow Outdoors

Onion Sets Collection (Heat Prepared) 1040-6017

Prevent and Supress onion white rot

White rot is a disease that affects bulb vegetables like onion and shallots. Once you’re onion crop’s got it, it’s impossible to cure as such and you’ll need to stop growing onions in the same spot for at least eight years. You’ll recognise it at harvest time by fluffy white mould with black speckles that grows around the base of the bulbs.

Have no fear there’s a great way you can prevent it getting to your onions in the first place!

Before planting your onions plant a crop of green manure called Caliente mustard. It’s a great organic means of creating a soil environment that’s uninviting to the disease.

Caliente mustard is a known as a bio-fumigant and once it’s chopped up and dug into the soil, it releases a natural gas that repels the pathogens that cause the rot along with many other soil diseases.

Just sow a pack from any time between March and October for a quick crop before your autumn-planting-crops or sow in November to overwinter for planting crops in spring. Just before it flowers, cut it down and dig well into the soil.

Caliente Mustard single packs can be purchased here.

Caliente Mustard double packs can be purchased here. 

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Our products are all grown with the utmost care and to high standards of quality. We regularly check our nursery stock to determine exactly when they will be at the optimum time for despatch.

We despatch our fresh, nursery-grown live plants (including vegetables, trees and flowers) when they are at a stage of growth ready for you, the customer, to plant on at home.

The delivery period shown on your order confirmation indicates when you can expect to receive your order and we will endeavour to despatch your plants in this period within 7-14 days