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Greenhouse lovers struggling to successfully grow lettuces should try older varieties, it has been suggested.
Recent research has found a number of heritage types to be more resilient, weather resistant and immune to mildew than the latest hybrids.
According to the Royal Horticultural Society (RHS), Garden Organic found 11 of the 12 best-performing varieties to be antiquated vintage ones.
"It wasnt what I expected," lead researcher Phil Sumption told the RHS.
"When you grow commercially you tend to always go for the latest new varieties"
The heritage lettuces tend to have fallen out of favour with large-scale growers now, although gardeners keen to get their hands on some may be able to source them from Garden Organics Heritage Seed Library.
A 1930s-style George Richardson was one of the better performers, being bested only by the modern Kitare.
Greenhouse enthusiasts may also wish to try Bronze Arrow and Rouge dHiver, which both did well in the study.
Those looking to help nurture the nations declining bumblebee population should combine a section untended garden with a flowerbed, according to Garden Organic.