Please help me save my Japanese Maple!

Hi all,

I bought a Japanese Maple earlier this year (early summer) and am experiencing some sort of a problem, possibly some form of dieback. I am not sure what the age of the tree is, but I do know it is in a 25 gallon pot and cost about $330 from Home Depot.

I still have not planted this tree yet because I had read that you should wait until fall to plant these trees in my area due to high summer heat. I live in Alexandria, VA (hardiness zone 7b).

The problem I'm having is that the branches (and subsequently, the leaves) seem to be dying from the tips of the branches inward. The affected branches also may be turning a darker color, but since this is my first time owning this tree I'm not sure if this is a normal branch color or if this is also part of the problem. The color they are turning is maybe purple or brown, I am a bit colorblind but that's what my wife says.

There are also some signs of leaf scorch but I'm not sure if this is related, and if it is due to underwatering or sun/heat exposure. I have maybe not been as judicious as I should have been with a watering schedule, but I had also read that these trees are susceptible to root damage from over-watering and to therefore err on the side of underwatering -- I have since read contradictory information saying that they should be well-watered, so not sure which source to believe.

My plan had been to cut off all the affected branches to stop this problem from spreading and begin watering more frequently. However, when I went out to begin trimming today, I realized that the problem is a bit more widespread than I realized. Not only am I worried about shocking the tree in a major way with the extensive level of pruning that would be required (followed by a necessary ground-planting before temperatures drop too far), I'm also worried that if I cut off every branch showing discoloration that I will be left with hardly any tree.

Therefore. I turned to online messageboards in the hope that I could get an answer from someone more knowledgeable about A) what problem I have and B) the best way to proceed.

I greatly appreciate any and all help, and thanks so much in advance.

Since it's still in the pot, it seems very unlikely that you could over-water it. Under-watering seems more likely. The leaves are being sun scorched. It is preferred to plant the Japanese Maple where it gets protection from the intense afternoon sun if possible. In other words, plant it where it gets morning sun but some afternoon shade. Since yours is still in the pot, it should be easy to move it to such a location.

BTW, you should probably get it out of the pot and into the ground.

Thank you for your reply! Yeah, I was going to plant it soon, but wanted to do the pruning and planting all at once so that the stress occurred at the same time instead of spreading it out over time. So step 1: identify the problem. Step 2: fix the problem. Step 3: plant the tree.

I had a large collection of Japanese maples. Oh how I loved them! Then 1 year, 1 by 1 started getting die back and black areas on their bark. Most were in pots. Out of 25 only 2 survived, A 'Shishigashira' and a 'Sango Kaku' which was in the ground and now years later is a huge tree.

At the time, I was told it was Verticillium wilt which attacks JMs, supposedly coming from the soil. Though in my case it was highly contagious jumping from potted tree to potted tree. I can't remember if I sterilized my pruners between trees way back then, but after I sure did. So maybe I spread it. Or maybe the potting soil I bought was contaminated and that started it.

Some trees would die in a couple of weeks, others took much longer. After a certain amount died, I started disposing of them as soon as the blackened areas appeared. I was so heart broken! I had some wisterias that I was training to be trees that caught it too and died quickly,
https://www.mortonarb.org/trees-plants/tree-and-plant-advice/help-diseases/verticillium-wilt

Yours might also be a bacterial blight like Pseudomonas Tip Blight
https://homeguides.sfgate.com/pseudomonas-tip-blight-japanese-maple-69781.html

https://www.mendocinomaples.com/black-stem-bad-news

Or it could be lack of water. Here is a good general article on JM in pots which discusses rootbound maples.
https://www.mercurynews.com/2019/08/28/bay-area-gardens-how-to-cope-with-japanese-maple-dieback/

I would wait to plant it in the garden until you are sure it is not diseased but do to your watering habits. If you notice black areas in between normal bark, I would say for sure it is diseased and not due to watering. And sterilize your pruners between cuts, I carried a spray bottle of bleach in water and would spray my pruners between cuts, alternating between pruners. It does ruin your pruners after awhile!

I might try to take it back to Home Depot, I think they have a return policy on plants. Some places have a 1 year return policy. If diseased, I would not be surprised if it was already infected when you bought it and the stress of moving it weakened it enough it became symptomatic.

Good luck!

PS
Google Japanese Maple die back for there are so many articles on it. JMs are prone to diseases sadly. I never bought 1 again.

This message was edited Sep 28, 2019 3:18 PM

I hope there is a warranty on it. You may be taking it back in a year or two if it dies.

I always get the one gallon sizes (15 to 20 dollars) and move them to a 3 gallon pot, after one year they go in the ground, and I get another 3 to 4 one gallon sized plants and repeat. If I lose one here or there, then I haven't lost a lot of money or a lot of work digging a hole. In a few years you will have some big JMs that would be hard to dig up.

I hacked my 15 year old weeping cut leaf JM this past winter so it would not block the dining room windows for Xmas wreaths. It has come back fairly nice but eventually I may have to get rid of it completely as this extreme pruning is a lot of work.

You can hardly see the top of the windows in May 2017 (and I do prune the side limbs and top every year). Pruned hard in early December 2018. Further pruned later on and new growth coming out in April this year. A month later. Final picture was the third week in July.

This is super helpful, thank you. Though I must admit, it is sad to see that some of these are fatal!

Ah, the life of a gardener. More plants have died in my yard than I care to remember. Maybe it is the life of a poor but ever hopeful gardener. LOL

Geez, Butch. You are so brutal. I could never do that. Put Christmas lights on it and forget the wreath!

My wife has mentioned (kinder word than complained about) this JM for years so last year I gave it a drastic haircut. Sometimes they need a crew cut?

At least the ones in the backyard have only dead limbs cut out as needed. Now if it would only rain (it has been weeks and we've had record breaking temps in September - we've had 85 days this year over 90 deg and we are expected to hit 94 today)

They look beautiful! Poor us, our spouses just do not understand the need! LOL

I’m not a Japanese maple expert but I would tend to think a combination of under watering and heat / sun. One of mine that’s in the ground for 10 years now is doing that same thing. We’ve had incredible temperatures this year. I would suspect disease less likely. I would go ahead and plant it within the next 3-6 weeks - not full sun. I would plant as is and wait until spring to see what leafs out before cutting anything back.

Thanks, all! I planted this and am hoping for the best! The branches do still seem healthy after the fingernail test and some of the darkened branches even started sprouting leaves.

We're zone 5 and planted a pair when starting our landscaping. Both made it through the first few winters, then one did not. We moved the survivor to a sheltered spot below the deck in a southwest exposure. It did well for several years and finally bit the dust. They are not hardy and it sounds like yours needs to be returned to Home Depot and replaced. This is too soon for it to be failing and too much money to spend on a dying plant. I do not think this is your fault. Those big chains sell substandard trees, shrubs expect that the customer will just sit back and not take action. Be assertive.