Tozer, the independent Surrey-based vegetable-breeding company, started making crosses of sprout and kale varieties in 1995. Development continued with the use of different coloured sprout and kale parent lines.
Just one variety has been released so far, but others in a range of colour forms and maturities will be available shortly.
Tozer representative Dr Jamie Claxton said: "Most breeding is done to improve existing varieties, but at Tozer we have flexibility in our breeding programmes — we can be more imaginative."
He added: "Breeding a new variety can take more than 10 years so it's a real sense of achievement when your product hits the market, I'm really excited about seeing flower sprout on the shelves"
The Flower Sprout, which has been developed using traditional hybridisation techniques, has a Brussels sprout-like plant habit, a tall stem with rosettes forming all the way up to a frilly-leaved top.
Extremely winter-hardy and with a similar cropping calendar to sprouts, the harvest window runs from October to early March from mid-March sowings. The taste is milder and sweeter than a Brussels sprout.
The name was chosen by Pam Johnson after a competition in Good Housekeeping via the website www.allaboutyou.com. The last new vegetable to be released was Tenderstem in 2002.
Several select growers are producing the new vegetable including Gloucestershire-based grower WR Haines. Martin Haines said: "We are very excited to be producing the vegetable. It tastes fantastic and we've had great reports from everyone who has tried it."
Flower Sprout is supplied exclusively to Marks & Spencer via Manor Fresh. Thompson & Morgan is selling the new brassica under the name Petit Posy in its 2010 seed catalogue.