Video: Peach-leaf curl – prevention

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.

Peach leaf curl disease

Peach leaf curl disease (Taphrina deformans) is the main issue you have to be aware of with peach, nectarine and apricot growing. I f you follow my guidelines you will have no trouble with this fungal disease.

Apricot has the same trouble, but in a milder form. However, if you cover your peach tree or your apricot tree with a double layer of garden fleece from late January until the middle of May, every year, or bring the potted tree indoors during the winter months, the disease cannot develop.

Peach leaf curl, photo courtesy of Scot Nelson/flickr.com

The fungus Taphrina deformans attacks the tree species of peach, nectarine and apricot.

The symptoms are the development of large reddish blisters on the leaves. The tree is seriously weakened as photosynthesis by the leaves is seriously affected.

Eventually the tree is starved to death as it is no longer able to make essential carbohydrates through photosynthesis. Leaves tend to fall prematurely and growth comes to a full standstill.

The fungus attacks the tree from early February until the middle of May. After May the fungus is no longer producing spores and therefore cannot cause new infections.

How to avoid peach leaf curl disease

There are various options for controllilng this fungus. Some varieties are more resistant than others. However this is no help if you already have to cope with this problem.

Actions to be taken immediately are the complete removal of leaves affected. This applies to the fallen leaves as well as the affected leaves that still attached to the tree. Make sure the leaves are all collected up, put in a plastic bag and then put in the non-recycling bin. Make sure the tree is well watered and does not stand in a carpet of weeds and grass. Apply a full watering can of water once or twice a week, particularly during the summer months. Mulch the tree with well rotted farmyard manure. The area to be mulched must be of a minimum size of one square yard.

Never let the tree go short of water! By late January cover the tree with a double layer of garden fleece. Fasten the fleece securely. Make sure the wind cannot affect it or lift it off. Keep your eye on the tree and if a tear develops in the fleece after particularly bad weather, repair the damage properly. This fleece needs to stay in position until the second week of May. After that time, carefully remove the fleece.

Never prune the tree during the autumn and winter months when the leaves have fallen. It is at that time that new infections occur very quickly. Prune during the middle of May or during late August, making sure the old wood is removed to make room for new shoots to form. This is essential as the fruits of peach and nectarine are formed on one year wood only. Seal the pruning cuts with “Prune and Seal”, a compound available from your garden centre. The foliage of a well pruned tree dries up quickly, with less chance of new infections.

If it is not possible to cover the peach tree, to avoid the disease you can spray with copper during the first week of February and repeat the spray 14 days later. Follow the instructions on the packet in detail. Garden centres stock it. At leaf fall in late November put on another spray of copper.

Peach leaf curl disease is spread by rain droplets. The fungus over-winters and is hidden in crevices of the bark and between the bud scales. Therefore consider planting a peach tree in a 15 to 18 inch diameter pot. By the end of January, wheel the potted peach tree into a cold shed or a cold green house or a cold poly tunnel. In that way no fleece is needed as the tree is sheltered from the winter rains. By the middle of May it is safe to take the pot outdoors again. Then position the tree in a warm sunny place and water it weekly or twice a week when very warm weather is occurring. Never let the tree go short of water as it will surely die.

Feed the tree monthly with a suitable foliar feed , obtainable from garden centres.

Read more about peach leaf curl disease.

Watch a video on how to prevent peach leaf curl.

Fruit tree maintenance in May and early June

Frequent visits to the trees at this time of year will prevent problems later.

Pests

Fruit trees are now well into the various stages of flowering and or growth. Lots of new green leaves are forming. These are very important for the trees’ wellbeing. At the same time, the leaves are excellent indicators as to how the trees are coping with various pests and diseases, which are also making their presence felt. Look at the growing points of the rapidly expanding twigs and shoots. If green fly or aphids are in the process of curling up the newly developing leaves it is important to remove the aphids with the use of non toxic fatty acid sprays or horticultural soap mixture. The garden centre stock various brands to deal with these problems.

If there are lots of ladybirds, make sure you choose a method of control which does not kill them. Ladybirds, lacewings and hoverflies are all very active predators of aphids. Caterpillar damage will be very easy to see this time of year. Remove if excessive numbers are present.

This time of the year the small song birds such as bluetits are consuming a large number of small caterpillars and feeding their young with them. These little birds are therefore a great asset to have aroud. Small nest boxes in the vicinity of the fruit trees encourage them to stay in the trees, just when you need them most.

Disease control

It is a very good routine to cut out and burn any foliage affected by peach leaf curl disease, apple mildew and scab. Do not leave it around on the ground as it will cause you even more trouble next year.

Tree canker must be cut out now, as at the moment you can still see it clearly. The same applies to silver leaf. Affected branches in plums need to be cut out and the wounds painted to prevent new infections.

Moths

Various moths that cause damage to fruit trees are becoming active from about now over the next couple of weeks. For example the plum fruit moth, whose grubs will live in the plum and greengage fruits, will cause a lot of damage. Now is the time to hang a pheromone trap in the tree. The lure will need to be replaced by early July to make sure the plums stay grub-free.

Fruit set and thinning

In spite of some earlier spring frosts, fruit set looks good in apples. It is variable in the earlier flowering trees such as plum, cherry, peach, apricot and pears. Trees of these varieties on frost-free sites, or that were adequately protected with garden fleece, may even have an excessive fruit set. Thinning should be carried out over the next 3 weeks to be effective. For example, apricots have set quite heavily and thinning is strongly recommended: it should be done now if you would like a good crop next year. The set on plums is variable. It would be best to wait a little longer before thinning, performing the operation once the level of fruit set is clearer. The same applies to peaches and nectarines.

Later on, after natural drop in June, it would be advisable to reduce the number of fruitlets in a group like this

Read our month-by-month fruit tree care calendar.

The effects of a Mediterranean climate on fruit trees in the UK this year

Moorpark, photo courtesy of sarahjb2007/flickr.com

Fruit trees have enjoyed above average rainfall and higher than average temperatures. The winter months were practically without frost and therefore the season started earlier. Most types of fruit ripened earlier than usual as a result of these weather patterns.

There are some negative effects as well. There is a lot more brown rot to cope with. Also various fungal diseases such as scab and mildew have caused problems for many people. Orchard hygiene is therefore very important. Removal of rots and scabby leaves from the orchard area is very important. If this is not done then next year the problem is likely to be even worse. This also applies to peach leaf curl. Do not store any affected fruit. Only store clean undamaged fruit.

Click here to read an article on dealing with peach leaf curl.

How to deal with peach leaf curl

Peach leaf curl, photo courtesy of Joel Ignacio, flickr.com

Did your peach, nectarine or apricot look odd with reddened, screwed up, puckered leaves?. Or no crop or very little? That’s most likely the result of the fungal disease “peach leaf curl” and frost damage. To begin with, now is the time – late October/early November – to collect all those leaves, infected or not. Do NOT compost them. Put them all in the non-recycling bin. Once the soil underneath those trees is clear of all litter, cover the soil with a 4 cm-deep layer of straw-based farm yard manure. Leave no gaps uncovered.

Phase 2 is equally important; it has to do with making sure that the “Peach leaf curl” fungus no longer has a chance to disfigure your tree. Make yourself a framework, as illustrated by the picture below, to stop the new young foliage becoming wet. Cover the wood frame with plastic or garden fleece. The framework is needed to stop the plastic or garden fleece cover, touching anywhere any limb or branch or  twig of the tree. By keeping the young newly-emerging foliage dry, the spores of the fungus are unable to germinate on the newly emerging foliage. Don’t forget these trees flower very early in the season. The new cover will also protect the blossom from damaging spring frosts. And finally when the fruits are nearly ready, the wooden frame is also very useful to fasten on to some netting, to stop the birds eating your peaches or apricots, before you had a chance to taste the fruits.

Frame for fleece on an espalier tree

Peach leaf curl disease

Peach leaf curl

If you grow peaches, nectarines and apricots, this is the main problem. It can be avoided bycovering your peach tree or your apricot tree with a double layer of garden fleece from late January until the middle of May, every year.
Peach leaf curl disease is caused by a fungus, Taphrina deformans. It will attack the tree species of peach, nectarine and apricot. The symptoms are the development of large reddish blisters on the leaves. The tree is seriously weakened as photosynthesis bythe leaves is seriously affected. Eventually the tree is starved to death as it is no longer able to make essential carbohydrates, through photosynthesis. Leaves tend to fall prematurely and growth comes to a complete standstill.
The fungus attacks the tree from late January until the middle of May. After May the fungus is no longer producing spores and therefore cannot cause new infections.

How to avoid these troubles

Actions to be taken immediately are the complete removal of leaves affected. This applies to the fallen leaves as well as the affected leaves still attached to the tree. Make sure the leaves are all collected up, put in a plastic bag and then put in the non-recycling bin. The fungal spores survive over winter on the fallen leaves!
Make sure the tree is well watered and does not stand in a carpet of weeds and grass. Apply a full watering can of water twice a week, particularly during the summer months. Mulch the tree with well rotted farmyard manure. The area to be mulched must be of a minimum size of one square yard.

Never let the tree go short of water! By late January cover the tree with a double layer of garden fleece. Fasten the fleece securely. Make sure the wind cannot affect it or lift it off. Keep your eye on the tree and if a tear develops in the fleece after particularly bad weather, repair the damage properly. This fleece needs to stay in position until the second week of May. After that time, carefully remove the fleece.

Never prune the tree during the autumn and winter months when the leaves have fallen. It is at that time that new infections occur very quickly. Prune during the middle of May or during late August, making sure that the old wood is removed to make room for new shoots to form. This is essential as the fruits of peach and nectarine are formed on one year wood only. Seal the pruning cuts with “Prune and Seal”, a compound available from your garden centre. The foliage of a well pruned tree dries up quickly, with less chance of new infections.