There are now very few treatments available to amateur gardeners that can control the various diseases that can affect fruit and vegetables. Prevention is always better than cure and good 'housekeeping' practices such as clearing away dead or diseased leaves will help. Aim to grow your plants as well as you can but do not over fertilise as this can lead to soft growth which is more likely to succumb to pests or disease. It is important to space plants correctly to maintain good air circulation around stems and foliage and make it harder for fungal diseases to establish. Try to keep foliage dry when watering and water in the morning rather than the evening if possible.
One of the most prevalent diseases which causes damage on many allotments from mid summer onwards is late blight which affects potatoes and tomatoes. It develops in warm humid weather and if there are a few days of this weather running it is likely to break out. It helps to make sure plants are spaced correctly and not crammed too close to each other, this allows the air to circulate more easily around plant stems and foliage reducing the risk of an outbreak. When watering these crops try not to get the foliage wet and water in the early morning if possible rather than the evening. If late blight does break out it can be held in check, though not eradicated by the use of copper based fungicide sprays such as Bordeaux mixture or Vitax Copper Mixture. Diseased plant material should be removed and burnt or disposed of (not composted unless you have a large heap that gets very hot, or a hot bin composter)
There are some potatoes varieties that are resistant to the various different strains of blight, most of whiich are pre-fixed 'Sarpo' If you suffer from blight another good idea is to only grow first and second early potatoes which have usually finished cropping before blight becomes a serious problem.
There are some varieties of tomato that are sold as blight resistant such as Legend and Ferline but recent strains of blight have affected these varieties as well as the old favourites. Work is being carried out to develop new varieties of tomato but if you suffer from blight every year the only way to prevent it is to grow under cover in a polytunnel or greenhouse and keep that well ventilated.
No products are currently available to gardeners to control these and other fungal diseases on top fruit trees. We recommend clearing up any diseased fallen leaves and burning them or disposing of them in domestic refuse rather than composting them. It also helps to feed, water and prune trees in line with expert advice to help ensure new growth is healthy.
The allotment shop at Pippenhall is now closed for the winter break reopening in early February 2024.
One of our members has experimented with growing potatoes in bags over the last two years. Read about his experience and advice to other container growers here
One of the tenants at Pippenhall has recently started a Pippenhall allotment blog. Have a look for yourself and register if you would like to contribute to this community. Click here to visit the blog
Eltham and Avery Hill Gardens Society
London SE9 2PE
(please do not use this address for correspondence)