Onion Sets - Red Ray Great flavour and ruby colour The exciting Onion sets - Red Ray is a true must have in your vegetable patch or allotment. This is a uniform variety that boasts an excellent ruby red skin, accompanied by an amazing flavour. Thanks to its very strong root system, the Onion Sets - Red Ray is a very productive variety that is suitable for long term storage. Heat Prepared Onion Sets Why buy heat treated onion sets? - It's frustrating when your beautifully forming onions decide it's time to develop seed and send up a flower stalk. Heat treating is a process that we carry out on your behalf to prevent this happening.