JPM - too much or too little?

I have a small Japanese Maple in a wooden box (2.5 x 2.5 x 2.0) on my deck. The tree is about four feet tall. Drainage is good (gravel about 3 inches on botton) and potting soil to the top. It has an eastern exposure and some wind from the north. Overall, tree has done well all summer, but lately I have noticed leaf burn on some of the branches. On these affected branches, all leaves are curling and and turning brown on the edges. On the unaffected branches, leaves are fine. I believe this could be from either too much water, too little water or wind burn. How to you know which is the case?

At this time of year some burn just happens on most trees. Containerized trees are the most likely to burn I've found and wind is hard on them. Do you know what kind of a maple it is? A photo perhaps? Some of them go dormant earlier than others. The Japanese Maple man locally says that overwatering causes leaf burn but since I don't change the watering over the summer time it doesn't make sense to me. I'm sure that there will be opinions. :-)

I had a seedling in a pot for years and every year the leaves would be dead by now. Stayed there for 30 years. To my shame I never even repotted it. It's in the ground now and never burns.

Also, trees are more likely to burn when they are in their first year I think.

Here's my Butterfly right now. It does this every year. I have another tree where the leaves are quite brown.

All in all, I wouldn't worry about it. You must be doing something right to only be getting leaf burn now. Keep up what you've been doing. Don't increase water though, it won't help. Don't fertilize, the tree needs to become dormant now, and next year you may want to try a product called Protek before you get leaf burn.

I noticed that you said that the soil was to the top of the box. Is any part of the trunk under the soil? If this is the case, that needs addressing.


This message was edited Sep 10, 2006 1:19 PM

Thanks Doss! Regarding the trunk, how do you identify the bottom of the trunk and the top of the roots? How should I correct if planted too deep?

If you scrape some of the soil gently around the trunk, you should be able to feel roots immediately - fine roots. If the dirt is above the roots, you can scrape the dirt down and when you do, the trunk under the ground looks damp then you have planted the tree too deep. If you did plant it too deep, at least remove the dirt that is laying against the trunk. If you can, remove the dirt to grade level with the new level of the dirt around the trunk. The most important thing though is that dirt not lay right against the trunk and that water not pool against it when you are watering.

If you can't do this now, repot it when it's dormant - I don't know how to treat trees in pots in cold places. Hopefully someone will come along and say.

Thanks again!!

IAplowboy, another term for used is the root flare of the tree. I have bought many Acer Palmatums and when I checked them they were planted 1" to 2" below the root flare. it's amazing that nurseries and landscape pros don't know not to do it. I'm surprised that they don't loose more young trees. I had a cousin call me about his trees dying and I looked at them and all had 2 problems. planted to deep and they were root bound. so we dug them up and cut the roots so they were spread out and planted above the root flare. now they are all thriveing. these were originally planted by a professional landscaper. Jim

I like the rootflare term. Very descriptive. I had a tree buried too deep from a good nursery but when I told them they had to replant every tree from the same supplier. Do you have this problem plowboy?

doss, I've seen this thing quite a lot myself, visiting local nurseries, I always pull the plant out of the container and look for root bound stock and planting depth. I've been scolded a few times, the way I look at it is, it's my money. good luck, Jim

You are a stronger person than I Jim. Maybe I should take you along on my next shopping trip??? :-) My nursery is very good and promised to replace the tree if it didn't do well. It was a field grown tree and hadn't been in it's container very long. The nursery said that they wouldn't buy from that supplier any more. I generally don't worry about root bound maples though. The bonsai people root prune them regularly and mine always get too big anyway. Now if it were another plant or if I wanted it to get big..........