Plum tree sap - Ask Extension
My plumb tree hass lots of sap coming out of its trunk snd I didnt get fruit last year or this year the tree seems healthy but I dont use chemicals ...
Knowledgebase
Plum tree sap #878923
Asked July 26, 2024, 2:36 PM EDT
My plumb tree hass lots of sap coming out of its trunk snd I didnt get fruit last year or this year the tree seems healthy but I dont use chemicals on it or my apple trees
Anne Arundel County Maryland
Expert Response
Oozing sap is called gummosis, and it can have several causes ranging from wood-boring insects, bacterial or fungal infection, response to an injury, or simply stress from environmental conditions like high heat or winter injury, drought, or over-watering.
Stone fruit trees (cherry, plum, peach, etc.) are unfortunately prone to gummosis, and are also vulnerable to borers and infection, especially if they are first stressed or damaged by cuts to the bark. We can't tell from the photos if the gummosis in this case is just stress or possibly due to borers or cankers (a type of infection of the wood).
Unfortunately, if borers or infections are involved, there isn't much you can do except to minimize tree stress and see if they survive, since pesticides will not provide any benefit at that point. Methods to reduce stress include just making sure that they are monitored for watering needs during dry spells and our ongoing drought, and avoiding having mulch piled against the trunk and investigating if the tree is planted too deeply (if the root flare is not visible, for instance) so it doesn't develop problems like girdling roots. We do see what appears to be landscape fabric or plastic around the trunk base in one of the photos, and this might be a contributing factor. If possible, since roots might have tangled with it by now, it should be removed, or at least as much of it taken out as is accessible.
If the canopy of each tree looks fairly normal and vigorous so far (the tree in the photo looks okay), then it might be okay, though sometimes canopy decline lags behind trunk symptoms of damage like gummosis. If a tree with persistent gummosis does wind-up needing to be replaced due to decline at some point, you can replant if you want, and early autumn is a great time to install trees if they are available.
Plum, apple, and other fruit trees can be high-maintenance due to the wide range of problems they are vulnerable to; refer to the linked pages for care and prevention tips. If you opt not to spray, be aware that sometimes serious issues arise that can impact tree health and fruiting, and sometimes entire crops are lost in certain years due to a pest or disease outbreak. Sprays are used preventatively, so by the time certain issues arise, it's often too late to intervene for that year. Links to a recommended spray routine can also be found in the pages above (even if you opt to use organic chemicals if they are available, though they tend to be less effective overall).
Lack of fruit can result from poor pollination, usually due to weather conditions (too cold or wet while the bees would have been needed during bloom). It can also be caused by the loss of a pollination partner plant (another cultivar of apple, plum, or the fruit type in question) if the tree isn't a variety that can self-pollinate. If the tree you're growing isn't self-pollinating but didn't have this issue before, maybe a tree that was providing pollen that whole time grew in someone else's yard and is now gone, or just didn't flower itself well in the past couple of years. If a tree becomes more shaded over time by surrounding trees, that can stifle flowering and fruiting; fruit trees like apple and plum need at least 6-8 hours of direct sunlight in summer to produce well. And lastly, a late-spring freeze or frost can damage or kill fruit tree flowers (open flowers, but also sometimes closed buds), so the weather from year to year can also influence how well a tree fruits, because if the flowers die or are too greatly damaged, they will not develop into fruits, even if they were pollinated before it froze.
Miri
Stone fruit trees (cherry, plum, peach, etc.) are unfortunately prone to gummosis, and are also vulnerable to borers and infection, especially if they are first stressed or damaged by cuts to the bark. We can't tell from the photos if the gummosis in this case is just stress or possibly due to borers or cankers (a type of infection of the wood).
Unfortunately, if borers or infections are involved, there isn't much you can do except to minimize tree stress and see if they survive, since pesticides will not provide any benefit at that point. Methods to reduce stress include just making sure that they are monitored for watering needs during dry spells and our ongoing drought, and avoiding having mulch piled against the trunk and investigating if the tree is planted too deeply (if the root flare is not visible, for instance) so it doesn't develop problems like girdling roots. We do see what appears to be landscape fabric or plastic around the trunk base in one of the photos, and this might be a contributing factor. If possible, since roots might have tangled with it by now, it should be removed, or at least as much of it taken out as is accessible.
If the canopy of each tree looks fairly normal and vigorous so far (the tree in the photo looks okay), then it might be okay, though sometimes canopy decline lags behind trunk symptoms of damage like gummosis. If a tree with persistent gummosis does wind-up needing to be replaced due to decline at some point, you can replant if you want, and early autumn is a great time to install trees if they are available.
Plum, apple, and other fruit trees can be high-maintenance due to the wide range of problems they are vulnerable to; refer to the linked pages for care and prevention tips. If you opt not to spray, be aware that sometimes serious issues arise that can impact tree health and fruiting, and sometimes entire crops are lost in certain years due to a pest or disease outbreak. Sprays are used preventatively, so by the time certain issues arise, it's often too late to intervene for that year. Links to a recommended spray routine can also be found in the pages above (even if you opt to use organic chemicals if they are available, though they tend to be less effective overall).
Lack of fruit can result from poor pollination, usually due to weather conditions (too cold or wet while the bees would have been needed during bloom). It can also be caused by the loss of a pollination partner plant (another cultivar of apple, plum, or the fruit type in question) if the tree isn't a variety that can self-pollinate. If the tree you're growing isn't self-pollinating but didn't have this issue before, maybe a tree that was providing pollen that whole time grew in someone else's yard and is now gone, or just didn't flower itself well in the past couple of years. If a tree becomes more shaded over time by surrounding trees, that can stifle flowering and fruiting; fruit trees like apple and plum need at least 6-8 hours of direct sunlight in summer to produce well. And lastly, a late-spring freeze or frost can damage or kill fruit tree flowers (open flowers, but also sometimes closed buds), so the weather from year to year can also influence how well a tree fruits, because if the flowers die or are too greatly damaged, they will not develop into fruits, even if they were pollinated before it froze.
Miri