Booming sales of novel gourds and pumpkins should not lead to empty shelves this year, according to the company that supplies much of the seed to growers in the sector.

Technologist Jim Joby at Tozer Seeds told The Grocer that the company had risen to the challenge of unprecedented sales growth over the last year. "Orders were so heavy we simply ran out. And as a result this season we saw our butternut in supermarkets as early as August. Some had been grown as far north as Lincolnshire, and South Yorkshire."

It has been driven by the development of new varieties that grow much better in the UK's colder, wetter climate. Last year Tozer unveiled the first British-bred variety, which was the result of seven years of development.

And this year it is planning to showcase several types of butternut squash that are being developed at its annual trial days on September 27 and 28, at the company's headquarters in Cobham, Surrey.

With Hallowe'en approaching it is the time when Tozer evaluates up to 80 potential new pumpkin varieties, 60 edible ­squashes and some 20 ornamental gourds.

The latest butternut varieties have been imported from the US and are far sweeter with a Brix reading of between 15-16 degrees - double that currently available.

A decade ago squash was hardly ever seen on supermarkets shelves but it has become increasingly popular. "The unique hybrids, which are smaller-sized and more suited to prepacking and have a smaller cavity that maximises the amount flesh in the gourd, were also adapted to our weather conditions," added Joby. "When naturally cured it can be stored until March, creating a virtually eight-month season."

Tozer is also working on a mini squash that can be sold individually and fits in the microwave.