A cherry tree in a garden may not set fruit for several reasons. One reason could be the lack of pollination – the transfer of pollen from one cherry variety to another that is essential for fruit set. If you have just the one cherry tree in your garden, you can compensate for this problem by cutting a branch from another cherry tree in blossom, putting it into a milk bottle with water, and placing the bottle at the centre of your tree. Bees will then visit the flowers both of the branch and the tree itself, and perform the cross-pollination needed to get a crop. It’s a simple but effective technique.
Peach-leaf curl is a disease, caused by the fungus Taphrina deformans, that can be recognized because the leaves of the tree curl up and take on a reddish colour. It is very damaging to the tree and so steps should be taken to avoid it. The best system would be to grow peaches in a glasshouse, but when the trees are outside, ideally against a wall on the south side, what is really important is to ensure that during winter and spring, the buds and the wood remain dry. Here you can see that Dan has built a simple frame around the tree so that he can cover it with tarpaulin or some other type of waterproof sheet. Openings at the side encourage the wind to blow through the tree, helping to keep it dry. Once the flowering is over, at the end of May, you can safely remove the cover. If your trees suffered peach leaf curl last year, you have to ensure that all the affected leaves have been removed, because the spores on affected leaves are still very infective even after the leaves have been cut away from the tree and could easily affect it again. More information on peach leaf curl here.
In a previous video, Dan Neuteboom explained that it is best not to prune pear trees until it is clear which buds are fruit buds, and so should be left on, and which are wood buds, and so can be pruned to control the size and vigour of the tree. That was late February-early March. We are now in the middle of April, and the results are evident. The three different pear varieties are all fan-trained and so use a minimal amount of space on the wall. The trees are facing south, pollination is good (because of the proximity of different varieties), temperatures are good, flowers are dominant, and so a very good fruit set can be expected. Some thinning may be necessary, and that will be the subject of another video.
Mistletoe lives in association with various types of tree, such as oak or ash, but it can also grow on fruit trees such as apple. Mistletoe itself does no harm to the tree, but it does absorb some of the water and nutrients provided by the tree’s root system. It is generally described as semi-parasitic, but it is a green plant, and synthesizes at least some of the nutrients that it needs. It is possible that some of the substances that the mistletoe produces are transferred to the host tree, and so the relationship could conceivably be one of mutual cooperation, above all in winter when the mistletoe is still green and the host has lost its leaves. The relationship could be more complex than it appears at first glance, perhaps closer to symbiotic than parasitic.
In addition to encouraging kissing, in recent years it has been discovered to possess certain medicinal properties. Why are birds more successful than human beings in grafting mistletoe onto trees? The secret lies in the stickiness of the berries. The birds eat the seeds inside the berry, the sticky stuff sticks to their beak, and they clean it off by rubbing it onto the tree bark. So to have some mistletoe in your garden, you just have to encourage the presence of birds. Mistletoe itself is a good source of food for some birds, such as mistle thrushes and migratory blackcaps, and it seems to have a positive effect on biodiversity. If you are worried about the water and nutrients that the mistletoe is stealing from your fruit tree, all you have to do is to provide extra water in droughty periods, and organic matter such as some manure in the spring. It’s a good idea to provide a constant layer of mulch around the tree, not in contact with the trunk (take a look at this video), and right out to the edge of the canopy.
If you want to try growing mistletoe on a tree in your garden, here’s how it is done. Collect berries from the mistletoe on a tree in March or April (at this time of year the berries are ripe). The host branch should be at least 10 cm in diameter, positioned fairly high in the tree so that the mistletoe receives good light. The tree should be at least 15 years old. Locate a natural crevice in the bark, or cut and lift a small flap. Remove the seeds from the mistletoe berries and insert them into the opening. Place several seeds at every position you choose, because only a few of them germinate. You should plant the mistletoe in several positions because male and female mistletoe plants are needed for berries to form. Protect the seeds from the birds by wrapping some hessian around the branch. Click to watch.
Trees need a lot of help in the first five years of their life. When you plant a new tree, its root system has to completely regrow, and it can only do this if there is enough moisture. A good way of helping the tree in this regard is to put mulch on the ground around it. The mulch retains moisture levels in the soil and encourages the bacterial activity that causes its own gradual breakdown, so that it enters the soil and adds nutrients. Trees love organic matter. But mulch can also have a negative side. Mice may make their nests under the mulch and in the winter months they may eat the bark of the tree. This can be avoided by ensuring that the mulch is not in direct contact with the trunk.
Another important aspect of planting a new tree is to protect it from deer, muntjacks, hares and rabbits. As soon as you have planted a tree, put a guard on it straight away. In the case of deer, a higher protection may be necessary.
It is a good idea to take a look at your tree at regular intervals and assess its overall health. The colour of the bark provides a good indication of health. If the colour of the trunk and main limbs is a bright grey shade, you can be sure that there are no drainage problems, and the root system is happy. If on the other hand the colour of the main trunk is reddish, this is an indication that the tree has been waterlogged, and the root system has suffered. In this case the only solution is to try to improve the drainage.
At this time of the year, April, you can check for other diseases that are easier to locate when there are still no leaves on the tree, such as bacterial canker and ordinary tree canker which is caused by a fungus. If you find canker, use a special curved canker knife to cut it out. Cut away the brownish, canker-affected parts until the wound is entirely green. Then coat the wound with anti-fungal paint. The tree will heal the wound itself.
Dan shows us a 17-year old greengage that over the years he has transformed by removing the central leader. This creates a bowl-shaped tree in which the main framework branches slope upwards very gradually so that lots of light enters. This has stimulated the tree to produce flower all the way across the tree, even in the very centre. With plums and greengages, it is important not to prune in the winter. The pruning has to be done when the trees are still in full leaf, so that the risk of silver leaf is greatly reduced.
Dan Neuteboom shows us a 15-year old pear tree that was cropping irregularly. To improve the situation, he grafted a second pear variety onto the main variety, right at the centre of the tree, choosing a variety that flowers slightly earlier, so that the pollen of the grafted variety is ready as soon as the flowers of the main variety are opening. The system helps ensure good cross-pollination, encouraging fruit set, and therefore a good crop. An easier way to obtain the same effect is to place some flowering branches in a bottle and hang it in the tree. The graft is a permanent solution. See this video for more details on how to perform the graft. Click to watch.
Dan Neuteboom prunes a 10-year-old apple tree. The principle that he follows in pruning is to improve the entry of light into the centre of the tree, by making as few cuts as possible, removing branches that are at the wrong angle, or reducing multiple branches in the same position, and removing vertical branches. He bears in mind the shading effect of the branches when they will have leaves on them, and is careful to maintain a sufficient quantity of fruit bud, so ensuring a good crop. Click to watch.
Dan Neuteboom shows us two mature plum trees, one of which has been pruned badly, while the other has been pruned well. One will produce little fruit, the other will set a good crop. The first tree was pruned with a chain saw, removing large branches, creating large wounds, leaving branches that are at the wrong angles, without consideration of the overall structure. The tree will react by throwing out a lot of new wood which will produce shade and stop light reaching the centre. The second tree shows a good structure, with a strong central leader, large horizontal branches well furnished with two and three-year-old shoots which are the best for fruiting. A tree that has a lot of two to three-year-old wood well positioned to receive light is a tree that will crop well. This tree will produce masses of flowers, bees will pollinate it, cross-pollination is ensured by the other plum tree, and all being well, there will be a good crop.