Japanese Maple... needs help.

This tree is on a friend of mine's roof terrace. It's been declining now for a couple of years. It was in a fairly exposed and extremely sunny spot. I'm assuming it's a bloodgood, but I'm no acer palmatum specialist.... so I convinced her to move it to a sheltered corner spot where it will only get morning light, hoping that it will come back happier next spring. There are no signs of bugs and there are buds forming. It gets adequate water and has a large enough pot (maybe too large) and great soil. I'm not sure if she fertilizes. The wood appears green all the way through.

What do you think? Can we save it?
Is something else hurting it?
Could she have over fertilized?
What are the chances it will recover if it's happier in its new spot?

thanks so much for all your advice.

Photo #2

I think the move to a sheltered spot was a good idea. Some of that damage could have been caused by hot winds on a rooftop terrace and loss of leaves is a pretty common occurrence for JMs in the summer.

If the tree has been declining for a number of years in a pot I would suspect that some of the decline could be caused by less than ideal conditions in the pot. Is the soil retaining too much moisture? Has the tree become rootbound? Perhaps the tree could benefit from being repotted this winter and given fresh potting soil and some root pruning if it's needed.

Strange summer here in NYC, and I'm guessing elsewhere. Hot winds. Too much rain. High temps followed by rain. Who knows? It's all out of the books. And has been for three years or so. If anything the planter is too big, almost 36" wide, which is pretty big for a patio tree.

For those of you who aren't container people, 24" is usually more than enough.

Should say that still, I'm heartened to hear that you think moving it could be enough. I've asked her to replenish some soil each year and it's well drained so maybe it's just too much sun and hot wind.

Although you'll often hear that bigger is better for trees in containers https://sharepoint.cahnrs.wsu.edu/blogs/urbanhort/archive/2011/03/23/plant-containers-does-size-really-matter.aspx#postComments I've read many people on this forum and elsewhere say that they think Japanese maples grow better in pots that are maybe just slightly bigger than the rootball and my experience affirms that . . . no matter what the scientists say!

I would agree with that. I looked at taking it out but it's spread out so far that I didn't want to start root pruning while it was already under so much stress. My beni schischihenge is doing fine in a 19" pot. Let's hope that it likes its new home.

thx

I have taken maples out of pots every 8-10 years, washed the soil off the roots completely, trimmed back the large roots and repotted back into the same pot. I do this in the spring just before bud brakes and even when the plant has broken bud and is about an inch or 2 in growth. I like to use organic soil with aggregate of sand, pea gravel, or perlite along with quality top soil. This way the plant drains quickly but has moisture retention. I have had plants dated back 50 years in pots with no problem doing this.

Dave

Can you keep these trees in the pots through out winter, or do you bring them inside?

I leave them outside on the north or east side of a building away from the thawing and freezing that comes from the south or east side. Also most of the winds came from the south or west. I also had other in white plastic covered houses but they needed water once or twice a winter.

Dave

Ok, thanks, That helps me a lot. I know most of my winds come from the west side. That must be why I can have Inpatients come up from seed on my north side flower bed.

Dave--Just hearing you have a tree 50 years in a pot, makes my heart leap. I have, in the past, washed off roots with great success but a lot of people say not to do it, so I'm heartened to hear that as well. My trees are coming up on six years so I've got some time, which is just as well, as they are not coming out without breaking that planter. I use metromix for soil.

I would add one thing. I like to make sure my containers are either lifted off the ground or sitting on a piece of wood over winter. My containers sit on pavers and there is something about that combo that irks the roots. If they were on wood or the earth, I'd leave them, but if it's on a stone or concrete terrace, I lift them up.

This message was edited Oct 14, 2011 10:43 PM

I am not and expert by any stretch of the imagination but it does not look like an ideal location. What about Verticillium Wilt. I've had a few Japanese trees slowly decline and I think it was VW because they were in ideal locations and got good care. I see many large maples here with a portion of the tree dead and think it is VW. Never fertilize a sick tree. Fertilizer is not medicine. Just my opinion for what its worth.