Young Redbud Trees - Ask Extension
We have a tree planting program with our schools in AA county. One of my volunteers send the attached pictures of redbud trees, which were planted in ...
Knowledgebase
Young Redbud Trees #878292
Asked July 22, 2024, 3:01 PM EDT
We have a tree planting program with our schools in AA county. One of my volunteers send the attached pictures of redbud trees, which were planted in the spring.
The volunteer said they are watering 3x per week. I explained that may be too much or too little depending on the amount and how the watering is being done. I have asked for clarification.
For Tree pic #1. "Ants carrying white stuff were seen climbing up from the root."
Can you tell from these pictures what problems these trees might have?
Anne Arundel County Maryland
Expert Response
The yellowing older leaves are probably responding to stress, which could take the form of over-watering, under-watering, too little soil nitrogen (though we would not recommend fertilizing in summer), or similar environmental causes that aren't a pest or disease. (The exception being root rot from over-watering, but in that case, usually entire branches or canopies wilt and discolor.)
As you noted, make sure the trees are only being watered when needed, which would be when the soil around six inches deep next to the root ball has become somewhat dry to the touch at that depth. When watering, we would guestimate (as it's hard to tell the tree's size) that a minimum of 5-10 gallons of water per tree be applied so the root zone is thoroughly rehydrated. One way to do this passively while also keeping track of the volume of water applied is to use buckets with holes in the bottom to drip water into the root zone slowly. (There's a quick video about this on the bottom of the linked page.)
The leaf damage in the close-up photo is inconsequential, and might have been caused by minor insect feeding that does not need treatment. The leaf damage in picture #2 looks like just scorch from moisture stress and high temperatures. If it were a leaf infection, though, it would not need treatment either.
We don't know what the ants might have been doing, though if a photo or two can be shared, we can see if it looks like they're causing any problems (unlikely).
Another precaution would be to avoid herbicide exposure if any weeds are treated (any time of year) in the lawn surrounding the trees. Certain herbicide ingredients can damage tree roots or distort foliage and will not be curable; we have seen leaf damage to redbuds in circumstances where they were exposed to either soil-applied or airborne (evaporated from a treatment area nearby) herbicide. The symptoms pictured here don't look like herbicide injury, but we mention it for future seasons.
Miri
As you noted, make sure the trees are only being watered when needed, which would be when the soil around six inches deep next to the root ball has become somewhat dry to the touch at that depth. When watering, we would guestimate (as it's hard to tell the tree's size) that a minimum of 5-10 gallons of water per tree be applied so the root zone is thoroughly rehydrated. One way to do this passively while also keeping track of the volume of water applied is to use buckets with holes in the bottom to drip water into the root zone slowly. (There's a quick video about this on the bottom of the linked page.)
The leaf damage in the close-up photo is inconsequential, and might have been caused by minor insect feeding that does not need treatment. The leaf damage in picture #2 looks like just scorch from moisture stress and high temperatures. If it were a leaf infection, though, it would not need treatment either.
We don't know what the ants might have been doing, though if a photo or two can be shared, we can see if it looks like they're causing any problems (unlikely).
Another precaution would be to avoid herbicide exposure if any weeds are treated (any time of year) in the lawn surrounding the trees. Certain herbicide ingredients can damage tree roots or distort foliage and will not be curable; we have seen leaf damage to redbuds in circumstances where they were exposed to either soil-applied or airborne (evaporated from a treatment area nearby) herbicide. The symptoms pictured here don't look like herbicide injury, but we mention it for future seasons.
Miri
