Orchard hygiene and tree health
A lot of the diseases that can afflict fruit trees are caused by fungal spores that infect the tree through even a small wound. It is possible to reduce the chance of infection by simple operations of orchard hygiene that make it possible to grow quality fruit without the use of chemical pesticides and fungicides. The basic principles are: eliminate the sources of fungal spores; and seal any open wounds on the tree.
Once you have picked the fruit and removed non-productive branches from the tree canopy, remove all the fruit left on the ground and eliminate it – in other words, not on the compost heap! It has to go into the non-recycling bin. This helps reduce the number of spores floating around your trees.
Remove any branches affected by mildew. They’re easy to spot, because they have a silvery appearance. If irregular brown growths are appearing on some of the branches, these should also be cut out. The same goes for wood infections such as tree canker or bacterial canker. Take a look at the tree ties on the trunk and branches to ensure that they haven’t become so tight that they’re ingrowing. After all this, cover any wounds with a sealing compound such as “Heal and Seal” using a smallish paint brush.
In winter, there will be more orchard hygiene work, but we’ll get to that in due course!
A good look once a week
A good look at your fruit trees once a week is all its take for your fruit trees to do well.
Trees can look after themselves reasonably well once they have been in the ground for a year or two. It is the first 2 to 3 years when the trees need a helping hand from time to time. This has all to do with the fact that trees, like everything else that grows in your garden, will need to adjust to the prevailing conditions. By that I mean it will take time for the various predators to settle either in or close by your trees to keep the various pests under control. For that reason young trees often suffer from aphid attack in spring. As soon as you notice that some leaves are beginning to curl, open the leaves up. If aphids are present then you have to deal with this. You can try to remove them with water or organic soap. Or your garden centre will have a wide variety of liquids, organic or otherwise to deal with this problem. You can also try to cut the affected leaves off and put them in the non-recycling bin.
In my experience, orchard hygiene and companion planting are the two most important factors in keeping pest and disease pretty well under control, without having to resort to sprays and various chemicals. Patio trees are often found to be in very good condition. The simple reason is that as a matter of routine any diseased or distorted leaves have been regularly removed during the growing season, from the patio.
Therefore it is a very good habit not to let things drop on the ground or anywhere near the trees, but to put diseased twigs or leaves in the non-recycling bin. In that way one avoids a build-up of various afflictions.
Fruit that has dropped, or rotting fruit, must not be left under the trees.
If your trees are in the chicken run then things become easier still, as the chickens are fond not only of the dropped fruit but also remove lots of grubs and caterpillars which otherwise would have had a go at the ripening fruit.
Many of the scab and mildew spores overwinter on fallen autumn leaves and twigs. To avoid re-infection in the following spring, it pays to remove and dispose of the old leaves by the end of November/ December. From that point of view it is a good move to tie grease bands around the trunks of the trees. Most garden centres stock them. It will stop various insects such as the winter moth from crawling up the trunk of the trees and causing damage to foliage and young fruitlets.
As mentioned earlier, over the medium term it is an excellent idea to build up the numbers of predators of the various pests which may harm the fruit and the leaves. Each predator has its own specific host plant, tree or bush. If you have the room to grow these various plants, then the various pests will be kept under control by natural means.
Hover flies, lacewings and ladybirds are all very active in keeping various pests such as aphids and red spider mite at a low level. Nasturtiums, marigolds and fennel attract hover flies into the garden. Earwigs consume many young aphids in various stages of development. They like to overwinter in upturned flower pots filled with straw or short cut bundles of open bamboo canes.
Provided one is in the routine of feeding small birds such as blue tits and long tail tits during the winter months, these little birds consume lots of grubs and caterpillars which otherwise would have found their way into the fruits.
Finally, garlic sprays are abhorrent to many insects. These can be obtained from most garden centres, in case the predator numbers in a particular season are at a low level.
Orchard hygiene, a case history
A very good gardening friend of mine, who lives in one of the surrounding villages, has demonstrated in practice, year after year, how it is possible to grow all types of fruit without the intensive use of manufactured chemicals, irrespective of variety, pests or diseases, or bad weather conditions, such as low temperatures at blossom time. He takes great care to ensure that his trees grow in an environment in which the chances of infection have been reduced to a minimum, by practicing the elementary principles of good orchard hygiene.
Once he has picked the fruit and removed non-productive branches from the tree canopy, he makes a special job of removing any fruit left on the ground underneath the tree crown. He picks up all deteriorating fruit, however bruised or rotten it may be, and puts it all in the non-recycling bin. The net effect of this action is that there are less spores floating around his fruit trees next year, and so there is less chance of fungi finding a spot to infect his fruit. Another benefit of this is that his fruit is of better keeping quality.
In addition, he removes any wood affected by mildew. This is easy to spot as it has a silvery appearance. If brown irregular growths are appearing on some of the branches, he makes sure it is cut out in early October. Likewise, he cuts out wood infections such as tree canker or bacterial canker, and he ensures that any ingrowing tree ties on the branches are removed. The wounds are then covered with a sealing compound such as “Heal and Seal” using a smallish paint brush. This is very effective and stops new infection occurring this or next season.
During the winter months he will further attend to his trees and remove lichen and tree moss which are reducing the young branches’ ability to produce good strong fruit buds.