The usual cause of greenback is excessive heat in the greenhouse during the development of the fruit. The risk of this can be reduced by applying shading to the glass in early summer, damping down the greenhouse paths in the morning on hot summer days, and ensuring that there is adequate ventilation. All of these measures will help to reduce plant stress on hot days. Whilst it may be too late this season, we would recommend using all 3 of these measures next time.
Plants and gardens have always been a big part of my life. I can remember helping my Dad to prick out seedlings, even before I could see over the top of the potting bench. As an adult, I trained at Writtle College where I received my degree, BSc. (Hons) Horticulture. After working in a specialist plantsman's nursery, and later, as a consulting arboriculturalist, I joined Thompson & Morgan in 2008. Initially looking after the grounds and coordinating the plant trials, I now support the web team offering horticultural advice online.