Tuesday, May 20, 2008

Cotinus Care in Yonkers

Oh please tell me that it is still OK for me to prune "my baby" which is really starting to make me very worried. It is more like a tree than a bush/shrub and I've let it grow to high and I did not prune it hard by March 31. I did prune back the long branches but the base of the "shrub" is more like a tree shape having a right and left side with the middle having been destroyed in a hurricane two years ago. This year, only the left side is beginning to leaf with the right side still bare but amazingly, growth pushing up from the bottom. The leafless right side is alive - how do it know? - if I prune off a small branch, the smell is there and if you scrape the bark, you see green. I would estimate it's overall, crooked height to be about 5' tall.

So, after having read your article and only having about 10% of the shrub/tree in leaf, my question is:

Can I safely prune back now/today to approx 3' tall, fertilize and keep moist, and hope that it will begin to leaf more evenly?

This is the Queen of my Garden and I must save it and restore it to its overall beauty. I don't care if it flowers; I just want all the leaves to return all over the plant and enjoy them as they sway in the breeze and look like silver when it rains.

thanks for your help; it is greatly appreciated.

I asked if she could send me some photos to get a better idea of the situation and here is one:She also added:
Incidentally, I lost my first one. Following its demise, I sent a soil sample to Cornell in Illinois (I think) because I suspected verticillium wilt and I know this shrub does not do well under these conditions. I hope this one is not falling prey to the same fungus.

To date, I have fed it with Plant Tone but if there is something else that I should use to strengthen it, please let me know.

To all this I answered:
The left side I doubt is going to come back. There might be some green left in the tissue but it is not going to come back nearly as well as it once was, if at all. Cut the left side back to the ground and remove that dead stalk entirely. I also see that there is a stub in the middle which looks like it stands about 4”-5” tall with no growth. Cut that back to the ground as well. Since you are getting all that new growth from the bottom you might as well capitalize on that, even if it is not the ideal situation. It means in the long run the shape of your Cotinus will be quite different than the tree form it was, but it will certainly survive, and that’s the important thing. Cutting back that dead wood on the left side and in the center will continue to push out new growth from the base and you will end up with more of a shrub form. Ideally I would suggest cutting the right side stalk back all the way to the ground too, but since right now that stem has most of the plant’s foliage on it, I’m going to say hold off on that for now. In order for the Cotinus to have the best chance of survival, I am sorry to say it might look a little funny for this season, but with proper, spaced-out pruning it can still be a beautiful presence in your garden. On the right side I would remove any shoots that have no growth on them, of which I see a couple in the photograph. Prune them back to the next branch or trunk where there is healthy growth and foliage. While the shrub pushed out new growth from the bottom and establishes new leaf and stem tissue you want to remove as little living tissue as possible. As a general rule of thumb, you can always remove dead wood from a tree or shrub, but you want to allow the healthy parts of the plant to come out of dormancy and grow with as little stress as possible, especially early in the season. So, you will be left with a bunch of growth from the base and the “odd ball” stalk on the right side. Like I said, it will look funny, but if you remove the right side now the shrub might suffer too much stress. Therefore, I would remove the right stalk back to the ground, like the left and center pieces, but not until next winter. Next spring your Cotinus will then be a shrub form with new growth flushing out from all sides and you can prune it lightly to give it a better shape.

Regarding the fertilizer and verticillium wilt:
Do not go crazy fertilizing your shrub right now. If you have applied some Plant Tone to your garden this spring that is fine, but when it comes to perennials and shrubs, your plants are going to be happier if you don’t overdo it. Annuals and tropicals and turf can be “heavy feeders” as we call them, but over-fertilizing perennials and woody plants can force them to produce more stems and leaves than they want to and that can lead to unnecessary stress. Once established in the landscape shrubs have their own agenda and know their abilities and limitations based on the conditions they are living in, and often we should live with that instead of over-compensating to force what is not natural. Especially as a plant gets older it adjust to the nutrients in the soil and often does not want too much extra coddling. Also, regarding diseases, always be sure that you are taking care of the cultural needs of the plant before jumping to conclusions about dieback being the effect of a certain disease. Because a plant can be susceptible to a certain disease does not mean that that is your answer. I have been working closely with Cotinus for easily 10 years now and I can comfortably say that I have never seen one die because of Verticillium Wilt. Often irregular watering, soil that doesn’t drain properly, or being situated in an area without enough sun, those are often the culprits. If you do suspect a disease is present, be sure to familiarize yourself will all of the symptoms so that you can diagnose with the greatest degree of certainty. And either way, remember that proper plant care is always the best solution, disease or not.

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