Hi Would be grateful for advice for my acer Osakazuki. I planted this tree in the ground last year in April. With hindsight not the best location as a bit too sunny & possibly a little exposed too, but have kept well-watered and especially this spring which has been bone dry (I am in London, UK). It started to leaf up nicely from this April, but a couple of the branches remain bare. They have tiny buds on them but didn't swell and still have not opened for around 5/6 weeks now. I'm worried because they now look like they are shrivelling up and the branches feel dry & brittle. The colours are an odd mix of pale/ white and brown/ dark red/ black - slightly burnt-looking. I snipped off the ends of a couple of them and they are still green...just. But can't tell further down the branch as the bark is too thick to scrape. Does anyone know what is happening here? Should I cut the branches off? If so, where - right at the base where it's growing off the main trunk which is quite thick and feels a bit drastic as it's so much off the tree or further along where the branches are smaller? Also can this be done now or do I wait till autumn/ winter/ early spring next year? Many thanks in advance.
those branches look dead. can't tell you what the culprit is but i would cut all of them, all the way back to viable tissue, and do it now. that's just me.
There's a lof of cutting to do. Asap, and clean your tools after every cut with rubbing alcohol. I would like to see another picture that really shows the base, and up to the low area where we see the main branch that is blckening join. I fear that entire central branch may be lost, and also wonder if it wasn't planted too deep, which is exacerbating the problems. What was growing there before you planted? -E
Thank you for your input. Now I'm not just worried, but very! It's planted in what was just lawn which was removed and turned into a big flower bed with free draining good quality soil improved with a little horse manure. It was planted level with the soil level in its pot which I now gather may well be too deep for an acer. I have attached 3 further pics: 1 of the soil level it's planted at and the other 2 are of the low part where the problem branches begin, from 2 different angles. Hope you can see ok? Would appreciate advice on which parts to remove. Also if it is planted too deep, does it need to be dug out and replanted (not something I wish to do) or is there a tactical remedy that has been known to work eg scraping off some of the soil at the top?
It was planted in its pot? If so, the roots may be strangling themselves. EDIT: Sorry, I misread your post, you said level with the soil in the pot, but presumably removed from the pot. The follow up pictures you sent don't look good, particularly that black ring at the base of the trunk.
Yes, removed from the pot & planted in the ground at same level that it was in the pot. The 'black ring' isn't from the plant. Looks like some kind of dark blue mark that the original grower put on it. Not sure what it means. Doesn't look like a graft union, & I don't think the plant is grafted anyway. I'm going to cut off these dodgy-looking branches this week & hope for the best. Before that hoping for a reply from Emery to get their thoughts too. Thanks
That seems like the best plan. I have had similar maples shed very major branches and stems in the years after planting and then stabilise and maintain a healthy condition going forward. So it is not all doom and gloom! I have also had maples marked with some kind of paint or whatever on the lower trunk. I don't know what it is for, but I know it is a thing. Also regarding the depth of planting; the site seems to have a gradient? If so that is an advantage - I have found that Japanese maples are more tolerant of depth of planting on a sloping site.
Thanks maf. That's so reassuring - now I feel more optimistic. I really hope it will survive... heart-breaking and depressing if not. Good to know you've had markings on the base of the trunk too. So it's a thing. And well-observed re gradient! I'm guessing from how the fence is constructed. Yes it's on a slight slope - glad to hear that's a positive thing for if it's been planted too deep. The soil is pretty free draining - no issues with waterlogging but means it needs a good drink regularly. I give it at least half a big watering can once every 3 days or so in this hot dry spring weather we're having. Not sure if that's good practice but feels right and the tree seems ok apart from these dead parts.
The way Japanese maples are grown commercially in pots is not always in a way that prepares them for a life out in the wild. Often they have been grown under glass or plastic, overfed with chemical fertiliser to bulk up the above ground part of the plant, and when planted in ground the root structure is not large enough to support all of the existing branches. The plant then has no choice but to shut down some of the branches. With luck the decay is compartmentalised and the rest of the plant remains healthy. With bad luck secondary infections set in and the plant suffers further dieback and/or death. Hopefully your Osakazuki is in the former category.
Yes I hope so too. If it can get through the summer without further signs of decay and also give us a show of its autumn colour I'll be delighted. And then fingers crossed for when the cycle begins again next spring. Thanks for the advice and much-needed encouragement!
Hi, I haven't been at a computer, so I looked at your pics on a phone, but was hard to see much. Now back home, this is what I would do if it were my plant. Firstly, I think it's too deep, but maybe not critically so, because it looks like I can see some flare. I'd dig down around the central stem, and find where the major roots come out. For all we know, it might be girdled already, which would cause this sort of behavior. So this will let you find out. If the actual root flare is a cm or so below the surface, it's OK. If it lower, and the tree has been in the ground for less than 2 years, I'd pull and replant after the first flush is done, or at least in the fall. Did you knock all of the nursery soil off, so the roots are in your native soil? Nursery substrate isn't suitable for the ground, and maples are almost always planted too deep at the nursery. So the nursery soil line is a bad way to get the planting depth correctly. The branches with red arrows are dead, and need to be removed to the branch collar on the clean wood. The green branches look fine. What worries me is the branch with the blue arrow, and the area I've "circled" in blue where the dead branch meets it. This branch doesn't look clean to me, and I would scratch (with a sharp knife) a tiny bit of the circled area, where it looks like the infection (if that's what it was) bleeds into the main branch. If that cambium (just under the cut) is discolored, brown, or anything but healthy green, I would also remove the branch with the blue arrow. The black around the graft is nothing to worry about. It looks like it was grafted at quite a large size, they make have used wax on the graft, which is done in Spain sometimes, and Eastern Europe, and leaves just this kind of mark. So worst case, you lose a big part of the plant. The good news is, a lot of it still looks OK. Acer palmatum (or in this case Acer amoenum) is actually a pretty tough plant, with the exception of certain weak cultivars, so you're in with a good chance. I have a large, spreading Ō-sakazuki that has been sick with verticillium wilt for 25 years. Every once in a while it loses a major branch, I hack it off, and it looks unbalanced for a while. But it's still a beautiful tree. HTH, -E
To echo what @emery said I was thinking the blue arrow branch was likely a goner too. And I also agree that nursery substrate is a bad idea in ground.
Thanks a lot for taking the time to be so helpful with your thoughtful advice. I'm glad and heartened to hear you're still enjoying your Osakazuki many years on despite suffering long-term sickness! So I dug around the central stem further and couldn't find any roots. It's clearly been planted too deep (not by me I hasten to add!). As of right now I have little inclination to dig it up and replant but may feel differently come autumn. Have to weigh up risk/ reward as it's already a sizeable tree and will require effort. It was planted straight into the ground from its pot, soil and all, like how it's done with almost all other plants so now I know for next time not to do so with acers. (Interestingly the RHS guidance on planting trees doesn't mention this specific detail with acers, or not that I could see anyway so how are novices like me meant to know?) Ok, I won't worry about the dark ring at the base. Yes, it looks like wax. I will cut off the dead branches marked red. One last further question if I may... where the white dead part meets a green part eg the top red arrow on your pic..is it best to ensure all the white is removed by cutting into the green, or best to avoid cutting into the green so take off as much white as possible without touching the green? I scratched a little of the blue circle and it was (surprisingly) greenish still so am going to leave the blue arrow part of the branch but cut the read arrow part above, hence my question. Thanks again, much appreciated.
Happy to help. Think of the RHS as a GP, who knows a lot generally, but typically not that much about specifics of nursery practices or Acer specific issues. As with your GP, there are times you need a specialist! If you join the Maple Society -- https://tmsbi.org -- you can get expert advice with a simple email. (If you click the link, you'll see our own Miles Heyward being interviewed by Monty Don at Chelsea last year). Plus lots of other great benefits. (This is actually the official forum of the Maple Society, which is why many of us hang around here). Nursery soil: Differences in soil density inhibit water flow. That's why you want to plant in native soil. So essentially, your maple is in a pot without drainage. Maple really hate "wet feet", by itself that could be causing a lot of your problems. WRT your question, you want to cut at the branch collar. Here's a link: https://www.thecelticfarm.com/what-is-a-branch-collar-2/ Disclaimer, I didn't read the whole thing, so maybe there are errors, but by-and-large it seemed on point. Don't cut inside the branch collar. This can cause your problems to increase if there is disease. What I would do: if the dead wood extends beyond the branch collar, I would cut to a one inch stub. If it doesn't I would cut to the collar, a normal/correct pruning cut. Do not use cut paste. I would also prophylactically pulverize copper solution on the tree every 2-3 weeks for the rest of the year. You can usually by Bordeaux Mix at Amazon or one of the online retailers. Don't over-water, that also could be the cause of many of your issues. Right now, your tree is playing against a bit of a stacked deck, I'm afraid. Good luck! -E
Thank you @emery - for the tips and for the helpful links. I'll take everything onboard (though you have definitely lost me at prophylac.....and Bordeaux Mix sounds like something you'd buy from a wine merchant :-)). I think I saw the interview with MD last year but will watch again, this time with renewed interest! Overnight the squirrels have helpfully dug deeper around the trunk and exposed some fine roots. Off to tackle some pruning now. And fingers crossed and some TLC after that. Thanks again all. May well be back again on here later for more hand-holding!
