rhododendrons - Ask Extension
Hello - my question is threefold.
First, I have a small rhodo that was purchased and planted in the fall. It has been through only 1 winter, but I won...
Knowledgebase
rhododendrons #393959
Asked April 16, 2017, 6:01 PM EDT
Hello - my question is threefold.
First, I have a small rhodo that was purchased and planted in the fall. It has been through only 1 winter, but I wonder if this is winter burn or a disease. All the leaves have small faint blotches, the lower leaves are brown at the edge. The stems are a bit yellowish. It does not look a healthy green. There is leaf mulch at the base since we planted it. If it is winter burn, can we expect it to come back?
Secondly, we trimmed a few "water sprouts" and crossing branches from a tree. I dont know what kind it is, but it gets tiny, very fragrant white tubular blossoms. It has been a week since we trimmed this, and it is still oozing sap, to the point that you can actually see it drip from the branches. I hope this wont cause permanent damage, as I thought this would have wounded over by now.
Lastly, I am wondering to what extent is the emerald ash borer in this area. We have had prevantative treatments the past 3 seasons, and now we wonder how close to our area these are at this time. Thank you, and I look forward to your help!
Northampton County Pennsylvania
Expert Response
I would wait to see what kind of growth you get on the rhododendron. It looks like the shrub wasn't well hydrated before it went into winter. With a new shrub, you need to keep watering right up to the first freeze. That's a good plan to continue for the life of the shrub because winter wind does more damage than freezing temperatures. Next winter, you might want to put up a burlap wind baffle around the shrub. Keep is a foot away from the shrub on all sides. This spring, put an inch of good compost on top of the soil in the root zone. I would repeat the spring compost into the future as a way to help the plant get started in the spring.
The reason the tree is oozing is it was coming out of winter dormancy when you pruned and the sap runs hard in the winter. Don't put any wound dressing on the pruning cuts. The tree will heal the cuts in time. Unfortunately, we had warm weather sporadically through the winter and are still unseasonably warm. Trees that you need to prune are best done in late winter dormancy, but this year I'm not sure when that would be. Friends of mine who tap maple trees found sap running in January. However, it stops running when the temperatures dip.
Pay attention to the wounds to make sure they start to heal. You will see the bark on both sides of the wound starting to grow over it like a callus. If you want to identify your tree, take a sample when it's flowering to your local Penn State Extension. It will be easier to care for the tree if you can find out what it is.
The reason the tree is oozing is it was coming out of winter dormancy when you pruned and the sap runs hard in the winter. Don't put any wound dressing on the pruning cuts. The tree will heal the cuts in time. Unfortunately, we had warm weather sporadically through the winter and are still unseasonably warm. Trees that you need to prune are best done in late winter dormancy, but this year I'm not sure when that would be. Friends of mine who tap maple trees found sap running in January. However, it stops running when the temperatures dip.
Pay attention to the wounds to make sure they start to heal. You will see the bark on both sides of the wound starting to grow over it like a callus. If you want to identify your tree, take a sample when it's flowering to your local Penn State Extension. It will be easier to care for the tree if you can find out what it is.
