The main branch on my viburnum carlesii (I think it's carlesii) has turned dark brown. The leaves aren't brittle/crunchy. Instead their sort of leathery. There are several sprouts coming from the root that look healthy. Does anyone know what this might be? I'll post a closeup in Part 2.
tia
las
LAS14 you can post your pictures all in one thread/topic instead of opening a new one each time. Just reply to your own thread/topic for each picture you want to add.
As to the dieback, Viburnums are susceptible to two main diseases, verticillium wilt and botryosphaeria dieback. The first is usually fatal. The second is survivable. Did the leaves yellow, then brown? Or did they just blacken somewhat suddenly, maybe after heat stress? Cut off a dead branch and look for brown discoloration in the inner wood. If you see some brown discoloration it's probably verticillium wilt. It would be helpful if you could post a picture of the base of the brances at the ground ( in case of trunk damage) and a closeup picture of the cut end of a dead branch.
OK, here is the first of the pictures you requested - a cross section. I didn't cut the whole main branch because I have seen other trees/bushes recover after complete leaf death (birches and Siberian pea trea). So I have hope.
As to your other questions. My hubby and I both believe it just went black, but couldn't swear to it.
Definitely no heat stress. This is a record breaking cool summer in Maine. Our lettuce batch still hasn't bolted!! It's September 3rd. Also, remember that the leaves are leathery, not crispy.
Let me know if this close up isn't close enough. I'm still getting used to this digital camera.
This message was edited Sep 3, 2009 10:08 PM
This message was edited Sep 3, 2009 10:10 PM
Here's the first of two pictures of the base of the shrub.
It's difficult to tell if there is brown streaking from this photo. Please look at Figure 2 in the accompanying link. Verticillium wilt attacks a larg number of trees and shrubs. The brown streaking looks the same for all.
Also, if there is no green layer under the bark when the bark is scratched off then it's dead. The green layer is the cambium. The cambium is the essential business part of the plant transporting water and nutrients from the roots to the leaves and back. No cambium means no life activity.
http://www.ces.purdue.edu/extmedia/BP/BP_6_W.pdf
This message was edited Sep 3, 2009 10:13 PM
Here's the second of the base pictures.
Whoa! There's something that happened to the trunk(s) at the base. They look damaged. Possibly rabbit chewed. If a rabbit chewed off all the bark and destroyed the cambium that's the cause of the dead branches. It's possible you might get some sprout growth from the roots. I don't see any new shoots though.
Oh, wow, thanks! You spotted something in a picture that I couldn't see when I was staring right at it. Yes, indeed, there are sprouts coming up from the root. I learned a lot of stuff from this little conversation.
Thanks again!
LAS
We've never had this problem before, but I bet we had it on two viburnums this year (one has gone to the brush pile, so can't check.) We'd like to wrap something around the lower trunks of our other viburnums and specially loved bushes. Do you recommend anything? I looked in "Garden Products," but found nothing. We were thinking chicken wire, but perhaps there's some commercial product that is in some way better?
tia
las
There are a large number of products on the market for protecting trunks from those miserable rabbits. My favorite though is homemade. I use hardware cloth, instead of chicken wire, and make circle cages. The cages can be used over and over again. I peg them tight to the ground for the winter and store them during the spring & summer. What I like about hardware cloth or chicken wire is that they don't trap any moisture or provide a hiding place for bugs like wraps can do, especially if the wraps get a little loose over the winter. Plus you can make the cage tall enough to reach the lowest branches. If a rabbit can't get an easy meal at the base of the trunk they will snap off branches as high as they can reach. Hardware cloth will stand upright without any staking but it should be pegged to the ground. Good luck!
