Top fruit tree growing advice and information from Real English Fruit

Monthly Archives: August 2019

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