Top fruit tree growing advice and information from Real English Fruit

Category Archives: Pest and disease control

Chainsaw surgery – treating bacterial canker. New video

Bacterial canker is a disease that usually kills a tree. In the latest video published on the RealEnglishFruit video channel, Dan Neuteboom explains how he treated a damson tree that was afflicted by bacterial canker, by cutting away the infected parts of the trunk with a chain saw, and painting the wounds with creocoat (a creosote substitute).

It’s easy to see when a tree has bacterial canker: dieback on parts of the tree, and dead areas of bark developing in spring and early summer, with brown gummy liquid oozing out of the trunk. Small round brown spots appear on leaves and later fall out, leaving small holes, known as “shotholes”.

It is an infectious disease, and so it’s best to prune stone fruit trees – plums, greengages, peaches, apricots etc. – only when the tree has leaves and is fully active, so during the summer, because in this period the tree has a degree of resistance to bacterial canker and can heal its wounds. By the end of August, no more pruning should be done on these trees.

Dan’s treatment of this particular tree was performed in July.

The disease is caused by plant-pathogenic bacteria Pseudomonas syringae, which exists in different forms specific to certain tree species. The bacteria land on the leaves where they reside on the surface, and can cause leaf infections in spring and early summer by entering the leaf spores, causing the “shothole” effect. Cankers develop when the bacteria exploit the wound caused by leaf drop or other damage to branches and enter the phloem cells just under the bark – the cells that transport sap rich in sugar and nutrients. The bacteria’s development here blocks the sap tubes causing the death of part or all of the tree.

Garden orchards, update for the month of August

This is a very important time in the fruit calendar. Many fruits are either close to picking or already being picked. The early plums such as Mirabelles, and likewise apricots, are being picked, and greengages, plums and early apple varieties will soon be ready.

Wasps are now very active and efforts have to be made to find the nests close by in order to reduce the numbers of these insects. The plum moth and codling moth have been a real nuisance this year. The lure and sticky pads in the pheromone traps in our area had to be renewed twice due to the large number of moths present. Woolly aphids have also been present in far greater numbers when compared to other years. Also bacterial canker, silver leaf and common tree canker in many cases have been a problem. Therefore, all considered, any wounds made during the summer pruning activities will need to be sealed with a wound-healing paint without delay.

Secondly it is most important that the essential summer pruning of peaches, apricots, cherries and plums is carried out and completed this month. The same applies to specially-trained apple and pear tree shapes such as fan, espalier, cordon and stepover.

Wherever possible, before pruning and picking, remove and destroy any damaged fruit such as fruit affected by brown rot. These fruits should be taken out of the orchard because they are infectious to other trees. If birds are a problem, nets will have to be put over the fruit to reduce any damage caused.

Apples this year are cropping irregularly in many places. Usually the young trees are fine and fruit needed to be thinned earlier in the year. This year, many older trees are showing a light crop. Pears on the other hand are doing well this year.

Finally, now is the time to prepare the containers that will be used for picking. In addition, check that the storage area for fruit is clean and free from mice, insects etc.

Video channel:

Here are some videos that may be useful this month:

How to control wasps in the garden

Pheromone trap for the sawfly

Summer pruning

Example of nets on a cherry tree grown on a wall

There is also a lot of information on the main website

dan neuteboom

Dan Neuteboom

Video: Ladybirds, great friends for fruit growers

A ladybird is the biggest friend the fruit grower can have. They inhabit fruit trees and eat the aphids. Unfortunately, this year – the video was filmed in May 2019 – there are far too many aphids when compared to the number of ladybirds, and so on their own the ladybirds can’t keep them under control. You can help by spraying the trees with a soapy liquid made with a washing-up liquid, at the concentration that you would use to do the washing-up. It won’t kill the ladybirds, nor the ants. But it will finish off the aphids.

Narration: Dan Neuteboom
Camera: John Paddy

Further information on the RealEnglishFruit website

Video: May – Mildew on fruit trees

In spring and early summer, mildew can develop on fruit trees very quickly, particularly in certain weather conditions. It’s a good idea to visit your trees every week, and when you do, be sure to bring a basket with you. Cut away mildew-affected shoots, and put then into the metal basket. From here, the shoots can disposed of, placing them into the non-recycling bin. The whitish appearance of mildew infection is due to the thousands of fungal spores on the leaves. Eliminating infected leaves and shoots helps control outbreaks of mildew.

Narration: Dan Neuteboom
Camera: John Paddy

Further information on the RealEnglishFruit website

Video: How to control aphids on fruit trees

This is a bad year for aphis. You can always see when you have an aphid attack because the leaves curl up. If nothing is done, the aphids will spread through the entire tree. There are ladybirds in the trees – these insects are predators of aphids and so help control aphid infection – but this year, the weather conditions have favoured the aphid presence and so the ladybirds cannot get rid of them. Ants are also a good indicator of aphids, as they milk them, using the sweet nectar that they exude as a source of food. To get rid of aphids on fruit trees there is a simple organic method. Spray the tree with a dilute washing-up-liquid solution, at the same sort of concentration that you would use to wash your dishes.
Narration: Dan Neuteboom
Camera: John Paddy

Further information on the RealEnglishFruit website

Video: Black aphids on cherry

In late May, we see a fan-trained cherry tree that has set a good crop and has healthy leaves, but it is also showing a problem. The young leaves are curled up, as a result of black aphids. These can be a problem because of the damage that they cause to the leaves, and in addition, the sweet nectar that the aphids exude also attracts wasps. Infected shoots should be cut right out and placed in a basket and eliminated. Don’t drop the cut shoots on the ground because ants will take the aphids back into the tree so that they can continue to use them as a source of sweet nectar. An organic treatment for cherry black aphids is to spray the tree with a diluted solution of washing-up liquid, the same sort of dilution that you would use to wash dishes, to the point of run-off.
Narration: Dan Neuteboom
Camera: John Paddy

Video: How to control aphids on apple trees

At this time of year (late May), you often see ants climbing up a fruit tree. They are there because they are looking after their herds of aphis. The aphids produce a sweet liquid that the ants collect and use as a foodstuff. So if you see ants going up your fruit tree, from the ground into the branches and then onto the leaves, you know that you have aphids. How can you get rid of the aphids on your apple tree? This depends. You may have enough ladybirds, hoverflies and lacewings to control the aphids naturally, and if the infection is not too bad, they will remove most of the aphids and the tree won’t suffer. However, if you find leaves completely folded up, there are too many aphids and it will be very difficult to do something about it. One way of controlling aphis attack is to spray the tree with a soapy liquid, with ordinary washing up liquid at the same concentration that you use to wash the dishes. However, this will not solve the situation when it has reached the stage at which the leaves are curled up. Another possibility is to use an organic spray called pyrethrum. This will be partially effective. The overall message is to make sure that the amount of aphis in your tree does not get too excessive, and take into consideration whether there is sufficient presence of predators to keep the aphis population under control.
Narration: Dan Neuteboom
Camera: John Paddy

Video. May: How to control wasps in the garden

We are not the only ones who like the fruit that we grow in our garden orchard. Birds, wasps and other things also like to enjoy the fruit. Wasps can be a real problem, particularly with plums and cherries. At garden centres they sell various types of trap, or you can use a simple home-made device. Just take a large jam jar, fill it half-full with a very sweet sugar solution in water, make a hole in the lid and place it near or in the fruit trees. The wasp will enjoy the sugar for the rest of its life. An easy solution of how to catch wasps in the garden.

Narration by Dan Neuteboom, camera John Paddy

Video: Plum sawfly treatment – pheromone traps

To watch the video, scroll down and click on the thumbnail. The plum sawfly becomes active in late May and the first week of June, and it stays active right up until we pick the plums. The sawfly itself is quite an attractive flying insect, with reddish head and thorax and a yellowish abdomen, but unfortunately it lays its eggs on the plum flowers, and the young plum sawfly larvae tunnel their way into the plums as they develop. So the net result is that when you are ready to enjoy your plum, you discover that someone else has got there before you. For plum sawfly control, you can use a pheromone trap to attract the plum sawfly. The pheromone mimics the scent of the male sawfly, attracting the female and preventing her from laying her eggs on the plum tree. The plum sawfly pheromone trap show here is triangular in shape, with a sticky cardboard base containing a lure that releases the pheromone gradually. It stays active for about 6 weeks, and then you have to replace the lure. This video was filmed on 28 May, so right at the beginning of the period in which these traps should be placed. Once the sticky board is full of sawflies, just pull it out and replace it. Garden centres sell packs of replacement sticky cards and lures which makes the process cheaper. So if you install a plum sawfly pheromone trap now, and replace it in six weeks time, it will greatly reduce the damage caused to your plums.

Plum sawfly life cycle

The plum sawfly life cycle begins when the female fly lays its eggs on the plum blossom. The larvae burrow into the young plum, which reacts to the attack by exuding a sticky resin – often the only noticeable sign of the presence of the sawfly. The larva eats some of the plum from inside, and the plum may drop to the ground early, or the mature larva may crawl out and drop to the ground. In any case, when in the soil, it forms a cocoon, well disguised by soil particles. It spends the entire winter in the cocoon at a depth of about 5 cm. It pupates at plum blossom time. Another method that can be used to control the plum sawfly is to gently loosen the soil around the base of the tree in late winter and early spring, giving birds the chance to locate the pupae and eat them.

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.