Fruit trees are a long term investment
Fruit trees are a long term investment; treated kindly they can reward year on year for easily 20 years or more. So having gone to the time and trouble buying and planting them it makes perfect sense to go that little bit further with your investment – keeping them in the pink.
A healthy fruit tree will not only yield more reliability and prolifically, the fruit quality will be greatly increased as well. It should be said now that left to their own devices the majority of varieties will get something at some time or another – there are a few quite common diseases that can make your trees look a little bit, well, worse for wear! Very few if any are absolutely perfect when it comes to warding off disease.
Don’t be disheartened for this article gives a few handy tips and pointers that are easily implemented if followed will ensure your trees remain in the pink and perform dutifully year after year. As if often the case a bit of foreknowledge goes a long way to achieving greater success.
Before we start be clear about the difference between a disease and a pest. Disease are caused by air, water or soil born spores and bacteria. Pests are usually insects that can themselves cause disfigured or discoloured leaves and growth. It is surprising how often erstwhile gardeners can be confused or nonspecific between the two.
1. Don’t overcrowd your trees
Spacing is important not only from a practical point of view – giving the trees room to grow allows them to develop properly and the space you will need for basic aftercare such as pruning and harvesting. But it also makes for healthier trees. Trees that are overcrowded are much more likely to be disease prone, congested foliage stays wet for longer and the decreased air circulation, shade and lack of direct sun all makes for perfect conditions for disease.
So when planting make sure you are aware of the minimum planting distance required for the tree concerned, don’t be tempted to squeeze too much in and always allow that little bit extra if possible. This will great benefit in the long run.
2. Prune correctly
Pruning is a basic for all fruit trees. Without it your trees will likely have poor form and poorer crops – because good pruning encourages the formation of flower buds. But if you prune too often or too hard – which may well be because as described in the first tip here because they have been planted too closely – it encourages a lot of soft new growth. And soft new growth is much more susceptible to bugs and disease.
3. Provide good soil conditions and aftercare
Trees that are growing healthily are much more likely to stay healthy. Good soil preparation prior to planting is key here. And so is aftercare. Ensuring trees don’t get stressed, have ready access to moisture and nutrients will go a long way to ensuring they are healthy.
So prepare the soil as well as you can beforehand. Irrigate during drier spells, and although this is vitally important to young trees that may not be fully established, it also brings rich dividends to older trees as well. A good thick mulch of woodchippings, turves or compost helps a lot in conserving valuable moisture.
Good feeding will not only keep them keep growing it will also help aid their natural defences. But make sure you don’t overdo it, especially with fertilizers high in nitrogen because this encourages soft new growth. A well balanced fertilizer such as bonemeal, potash or seaweed extract is ideal.
4. Choose varieties with natural resistance
When it comes to variety selection and the natural ability to defend pest and disease attack, not all varieties are equal. Some can be an absolute bane and are to be avoided. Others – in particular newer varieties – have much better resistance. Although no variety could truly be said to be infallible, by making the best choices initially you may save yourself work later on. Here’s some good tips:
APPLES
Red Falstaff A top class newer variety with red flushed fruits and crisp texture, mid season and will keep.
Saturn Again new and self fertile with sweet taste good storing capabilities and very reliable; top notch variety.
Katy Heavily red flushed second early variety, heavy cropper and sweet flavour. Very hardy.
Redsleeves First early but keeps better than most earlies. Small to medium sixed very red fruits, sweet white flesh, very good cultivar.
Suntan Cox type apple but a much better grower, wonderful taste and keeps but a vigorous grower so best on a smaller rootstock.
Antonovka A cooker popular in Northern Europe so hardy and reliable.
Blenheim Orange An old trooper which always grows well and often stays clean, distinctive savoury flavour, suits dessert and cooking with large fruits.
Meridian New with very good colour and growth characteristics, heavy cropper with pleasant flavour.
Greensleeves Self-fertile, crisp sweet taste, all-green fruits and very good growth. Season late September to October. Perfect garden variety.
Jonagold Medium to large fruit with very good texture, never soft. Prominent rosy red flush on a golden background, flavour sweet but with a balancing underlying acidity.
Limelight A compact grower so ideal for garden growing. Attractive lime-yellow fruits, flavour refreshing but not too tart, full of juice.
Paulared Not often grown in this country but should be better known. Handsome dark red fruits, sweet. Mid-season.
Hereford Russet A new russet with sensational complex flavour. Self fertile and reliable.
Bountiful Cooker which is easily pollinated, very good storing capabilities, until Spring when it can also be used for fresh purposes. Keeps it’s shape when cooked.
Arthur Turner Perfect for baking, Scottish heirloom variety with lovely blossom. Season September.
PEARS
Concorde First choice for garden growing. Compact, self-fertile, very sweet taste.
Beurre Hardy Large handsome fruits, full of juice strong grower and a very good variety.
Merton Pride Akin to the esteemed Doyenne du Comice but a better growing tree. Large fruits full of flavour. Needs two other trees to pollinate so best as part of a group.
Invincible New and self fertile. Medium to large fruits, stores.
PLUMS
Jubilee Best garden variety by far, hardy and reliable. Season mid to late August. Purple fruits for eating fresh but can be cooked also.
Violetta Beauitful egg shaped violet purple fruits ripen late July and early August. Dessert use.
Marjories Seedling Late ripening self fertile, dual purpose and reliable!
Excalibur Very fine quality fruits with a good flavour. Trouble free grower.
Purple Pershore Excellent cooking variety with plenty of flavour. September use, very hardy.
DAMSONS
Merryweather Larger and slightly sweeter than the Shropshire variety, an old favourite that always does well.
Shopshire Damson Traditional variety for jams, pies, etc, very robust flavour, fruits are smaller and plentiful.
CHERRIES
Morello Cooking variety that doesn’t get the same problems as sweet varieties. Self fertile, suits any aspect too.
And some to avoid …… Apples Cox’s Orange Pippin, Bramleys Seedling, Court Pendu Plat, D’arcy Spice, Plum Victoria and Pear Doyenne du Comice.
5. Treatments & Some Common Ailments
When it comes to treatments it cannot be stressed too highly that prevention is ALWAYS better than cure. If you can get into a routine of treating your trees early in the season – usually soon after the leaves unfold – then you will prevent most of the commoner ailments.
Apple trees
The two most common fungal diseases familiar probably to anyone who has ever grown or had an apple tree are powdery mildew and apple scab. Powdery mildew is easily identified because of the distinctive silvered new growths. It is especially prevalent in early Summer once growth is well underway and it tends only to affect new growths. Scab causes brown patches on the leaves. Both can be prevented with a broad spectrum fungicide such as Bayer Garden fungus fighter.
Apple trees are also commonly affected with rosy apple aphid and woolly aphid. They cause curled new leaves which often become sticky to the touch. Firstly snip off the tips of the worst affected growths. The apply a systemic insecticide. It doesn’t really matter which make it is as long as it is systemic. This means the treatment is absorbed by the plant and works from within which is better than relying on a contact only killer which can be a bit hit and miss if not applied thoroughly; additionally it means the tree won’t be covered by subsequent infestations whereas a systemic insecticide can give easily 5-6 weeks of cover.
Pear trees
With pears the most usually encountered problem is rust. Rust affects many different plants in slightly differing forms. Easily identifiable by the bright orange spots that appear on the leaves as they mature, it should be treated with an application of Manozeb or a similar fungicide suitable for rust, unfortunately treating after the rust has appeared usually has little affect so remember to apply the next spring to protect the tree.
Leaf blister mite causes the leaves to blister characteristically. Falling leaves should be raked up and destroyed. Chemical intervention is difficult.
Plums Gages and Damsons
Powdery mildew will affect these trees so treat as described under apple trees. They can also get rust as mentioned for pear trees above.
As for bugs and creepy crawlies greenfly and whitefly are the most common pests; again treat as mentioned under apple trees.
Grubs in the mature fruit is also a common malady and probably the one I am asked about most often. The inner fruits have a small caterpillar munching away inside when the fruit is cut open. This grub burrows out of the fruit when it is ready and pupates in the ground beneath the tree, emerging into a small moth the next Spring at around flowering time. The moth lays it’s eggs at the base of the flowers as they set and the tiny caterpillar burrows into the immature fruitlets to start the cycle again. By spraying the flowers with a systemic insecticide just after flowering time you can easily eradicate them.
Silverleaf is a very serious and fatal disease that is superficially similar in appearance to mildew. The way to differentiate between the two is to take a cutting of the affected wood. Inside the wood will be stained red if it is silverleaf. There is no cure and the tree should be removed; neither should you plant a tree within the same family in the same area.
Cherry trees
By far the most common problem with cherries is blackfly which thickly affect the new leaves causing them to curl and become sticky. They are easily seen clustered inside the curled leaves. Snip off the most badly affected growth tips and apply a systemic insecticide such as Provado.
Cherries can also get spotted leaves caused by various fungal or bacterial infections. Again an application of a good fungicide in Spring is recommended.
Peach and Nectarine
Peach leaf curl is an almost certainty unfortunately with these trees. It is so widespread and the only protectant was removed from sale because it contains copper which is no longer authorised. Peach leaf curl is easily identified because of the characteristic blistered and curled leaves which become affected soon after they have matured in late Spring. It looks pretty unsightly but isn’t fatal. The only course of action to take is to remove the affected leaves and you will find later new growths come clean. Peach and Nectarine trees grown under cover – a greenhouse or conservatory – are less prone because the spores are spread by water, usually rain, so if you can water from the bottom rather than the top then this reduces the chances of infection. With trees grown outside drier springs with less rain usually see less of an occurrence with this disease. Apricots are not affected.
6. Growing Organically
It has to be said that having tried the various organic remedies on the market I haven’t found them to be very effective. So if you try to garden without the aid of chemicals your choice of options really is restricted to keeping the trees growing as strongly as you can to encourage natural defences and by making good variety choices in the first place.
With bugs and insect damage you can help restore the natural balance by encouraging beneficial insects to stay in your garden, you will probably still find populations of greenfly and other insects start to build up before natural predators start to do their work but over the course of the season they will often catch up. You can also buy biological controls– basically pots of young ladybird larvae as well as many other natural predators which can be released on to the trees to do their work.
