Guide written by:
John, Passionate gardener, Cambridge
Fruit trees are very susceptible to attack from parasites, ravaging insects (fruit flies, aphids, cochineal beetles etc.) and disease-causing fungi. If you want a decent fruit crop it's essential to carry out some regular treatments.
- Fungicides and insecticides
Treat your trees in the winter time
Winter is the ideal season for treating your fruit trees.
Since they're in a resting state, you can apply certain products that might otherwise harm the tree itself without causing too much collateral damage to other fauna.
Keep your trees clean
The first thing you need to do is destroy any colonies of parasites hibernating in the form of eggs, larvae or spores on the branches, trunk and surrounding soil; otherwise they will simply hatch and breed the following spring.
In autumn you can start by collecting dead leaves and windfall fruit as well as any left hanging on the trees. Ideally this waste should be burned.
During the course of winter, brush the trunk and the major branches to remove any moss and lichen that could provide a habitat for parasites. The best thing to use for this is a weeding brush.
If you're using a metallic brush, don't scrape too hard as you might damage the bark.
Applying fungicidal products
Fungicides help fight off disease, while insecticides (surprise, surprise) battle insects and other small creatures detrimental to the health of the tree. Preventative treatment aims to prevent diseases or parasites from developing in the first place, whereas curative treatment aims to nurse an already-affected tree back to health; although they often make use of the same products.
Synthetic chemical products (pesticides) are being used less and less in the garden, and instead being replaced with alternatives that are less harmful to the environment. Note that use of synthetic pesticides may already be restricted or banned in some areas.
There are three main types of products currently being recommended, and totally compatible with the principles of organic agriculture:
- White oils (and vegetable oils)
- Lime-based washes
- Mineral fungicides.
Bathing the trunk in lime milk
Also known as tree limewash, lime milk is an entirely natural product that's been in use for years by gardeners.
Lime milk rids the trunk of moss, lichen, microscopic fungi, insects and larvae which inhabit the folds of the tree's bark during winter. It often removes the need for additional treatment against creatures like beetles, psyllids, aphids and codling moth larvae and diseases such as blistering, monilinia and scab. Lime milk should be applied in winter, usually on older trees with cracked or blistered bark.
Using a large, flat paintbrush, brush the solution onto the tree trunk and bases of the major limbs. For better coverage, apply a second coat before the first one dries.
Copper and sulphur are two totally natural products that have been used for centuries against fungal diseases. They are most effective if used preventatively or at the earliest signs of disease. Before treating, check that it's not likely to rain in the following 48 hours so as not to negate the effects of the treatment and have to start over.
Bordeaux mixture and other copper salts
Bordeaux mixture is a cornerstone of organic cultivation. A combination of copper sulphate and lime, it acts most effectively against mildew but also against scab in stone fruit trees, monilinia affecting plum, quince and pear trees, blistering in peaches, oidium in apple trees, etc. Such treatments on fruit trees must be carried out at the right moment: firstly when the leaves fall in autumn, then during the winter, and the third phase right at the start of spring.
Suplhur is the best preventative and curative remedy for oidium, also used against scab and blight. Apply the suplhur using a crop sprayer at a rate of 6g per litre of water onto the leaves, before the flowers blossom, in order to prevent germination of spores.
If it ain't broke... Never apply treatments on a tree which doesn't need it, as they won't do any good. Don't treat in icy conditions, and pick a calm, dry day to avoid wasting your product.
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Guide written by:
John, Passionate gardener, Cambridge, 47 guides
When I was young, I was already working in the family garden. Perhaps that is where my interest in plants and gardening came from. So, it was logical for me to study both plant biology and agronomy. At the request of various publishers I have, over twenty-five years, written many books on the subject of plants and mushrooms (a subject that is close to my heart).They were mostly identification guides at first, but shortly after they were about gardening, thus renewing the first passion of my childhood. I have also regularly collaborated with several magazines specializing in the field of gardening or more generally in nature. There is no gardener without a garden, I have cultivated mine in a small corner of Cambridge for the last thirty years and this is where I put into practice the methods of cultivation that will I advise you in as well.