Hi there, this year my cherry tree started out very well but then branches on on side started drying up, now other branches are drying up on different parts of the tree. The leaves starts wilting and then drying out. Is there any hope of saving the tree? will it be ok next year or should I just cut it down? should I try taking a good branch and propagate it? Please help.
Thank you for contacting the Toronto Master Gardeners with your question.
Cherry(Prunus) trees are subject to several bacterial or fungal diseases which could cause the general symptoms you have described. I will provide you with the most likely suspects , along with their descriptions of the symptoms, which hopefully will enable you to look for details that will enable you identify which disease. For example, several of the diseases on cherry trees present lesions or cankers on stems or trucks, which should be a clue to help you to either eliminate or hone in on the proper disease.Once you best match the symptoms , please refer to the recommended treatments where applicable.
But in all cases, when trees have dead branches they should be trimmed off back to healthy growth.
Trim the dead material back to the main branch where there is living tissue. Dispose of the branches and make sure there is no debris around the tree that could be causing any disease. If you need to do any pruning to restore shape or increase air flow through the canopy, it is best to do the pruning in the winter when the tree is dormant.
- Bacterial Canker
Description: Bacterial canker is caused by the bacteria Pseudomonas syringae. that causes the bark on affected limbs turns brown and those limbs or trees may refuse to bloom or leaf out in the spring. Sometimes though , the trees will leaf out, but these new leaves quickly wilt and die . Severe winters seems to enhance this disease.
Mechanical removal is recommended for any affected branches. Cut at least 6 inches below where you see any brown spots or lesions on branches, and keep going until you find healthy wood in case the infection is spreading inward. Disposing of infected tissues immediately can also help stop the spread of this disease.
There are no chemical controls registered for control of bacterial canker which is of
significant concern to cherry growers.
Please refer to following link for more details on bacterial Canker;
2. Twig Blight
Brown rot infection occurs through blossom parts and progresses into the twig, killing blossoms, spurs, and associated leaves. Small cankers on twigs form below infected spurs; gum may be present at the base of flowers and dead flowers remain on the tree. Beige-colored spore masses develop on diseased flowers under high humidity.
Rainy weather during bloom promotes the infection of flowers and young shoots, but severe blossom infection is uncommon.but remain in the tree to spread the disease to fruit.
Removing infections as they occur reduces the spread of this disease. Infected fruit shrivel into “mummies”, but remain in the tree to spread the disease the following spring. Mummies can be easily removed when pruning in winter or early spring.
Fungicides (where available) can be applied before bud break.
3. Cytospora canker
Cytospora canker is a significant disease of all stone-fruit trees. Cankers are
produced on scaffold limbs or trunks of infected trees. The primary symptom is the
presence of dead twigs or branches after the tree has leafed out in the spring. Closer
examination of dead limbs often reveals slightly sunken areas in the bark. Cytospora
canker may often be misdiagnosed as bacterial canker.
Small, black, fruiting bodies of the fungus often develop under the bark in the
sunken areas. Later in the spring, masses of spores are extruded from these structures.
Conidia (spores) are most abundant in the fall and spring. During rain or irrigation, spores
are splashed and blown around the orchard. Infection occurs through injuries to the bark
such as pruning wounds, leaf scars, winter injury and sunburn.
There are no known effective chemical controls available.
4. Black Knot (fungal disease) Black Knot is a fungal disease of cherries which causes causes twig and branch swelling and discoloration, resulting in girdling and dieback of branches and sometimes the main stem. Infection can occur on both healthy and mechanically injured woody tissue of the current season’s growth. The infecting spores arise from the black knots and spread by wind and rain.Brown, black woody swelling, knots on the branches of cherry.
Where possible, prune out and destroy newly forming galls to reduce their spread in the future. Avoid pruning when the spores are out between March and June. When removing woody galls, employ good pruning practices and make branch cuts at a distance from the gall. Disinfect pruning tools between each cut.
5. Phytophthora Root and Crown Rot
Leaves of infected trees wilt, dry, and remain attached to the tree. Chronic infections, usually of the roots, cause reduction in growth and early senescence and leaf fall. In an effort to distinguish a diagnosis, a key difference would be the absence of stem cankers and ozzing sap, in which case this fungal disease is more likely he cuprit.
Heavy or poorly drained soils , or extended soaking periods can be contributors to this fungal disease. Fungicides are effective in controlling this disease when used preventively, but they are seldom effective in reviving trees once the crown has become infected and moderate symptoms of decline have appeared.
Boscalid, captan, chlorothalonil, fenbuconazole, fenhexamid, ferbam, iprodione, myclobutanil, propiconazole, sulphur, thiophanate-methyl and triforine are registered in Canada (although not some are only available to commercial operations). Sweet cherry fruit appears to be susceptible throughout the entire period of development and continuous protection of the sweet cherry crop from bloom to harvest is required.
Please refer to following link for more details on bacterial Phytophthora Root and Crown Rot;
Other useful references:
General sanitation for removal:
When removing infected tree or branches, be careful not to expose other neighboring fruit trees in the removal process. Ensure that you are very thorough in sanitizing your pruning equipment (with rubbing alcohol or bleach), so as not to spread disease. It is also advisable to refrain from re-planting another fruit tree in this spot as a replacement, because these pathogens persist in the soil for several years, and will infect a new fruit tree.
Propogation of your cherry tree is very possible . You should use either semi-hardwood or hardwood cuttings. Semi-hardwood cuttings are taken from the tree in the summer when the wood is still slightly soft and partially mature. Hardwood cuttings are taken during the dormant season when the wood is hard and mature. First, fill a 6-inch (15 cm.) pot with a mix of half perlite and half sphagnum peat moss. Water the potting mix until it is evenly moist. Select a branch on the cherry , (ensuring there is no sign of disease, especially within the bark), that has leaves and 2-4 leaf nodes, and preferably one that is under 5 years of age. Cuttings taken from older trees should be taken from the youngest branches. Using sharp, sterile pruning shears cut off a 4- to 8-inch (10-20 cm.) section of the tree at a horizontal angle.
Strip any leaves from the bottom 2/3 of the cutting. Dip the end of the cutting into a rooting hormone. Make a hole in the rooting medium with your finger, then insert the cut end of the cutting into the hole and tamp down the rooting medium around it. Either place a plastic bag over the container or cut the bottom out of a milk jug and place it over the top of the pot. Keep the cutting in a sunny area with a temperature of at least 65 F. (18 C.). Keep the medium moist, but not too wet. Also provide some ventilation , o as not to attract fungus.
Check the cutting after 2-3 months to see if it has rooted by pulling on it lightly. If you feel resistance, continue to grow until the roots fill the container. When the roots have encompassed the pot, transfer the cutting to a gallon (3-4 L.) container filled with potting soil.