Hello! I planted this Acer Japonicum Yama Kage around a month ago. Before I planted it the trunk was a green color (pictured on the left next to a Twomblys Red Sentinel), now it’s red (which I am sure is fine), but it has developed a dark coloration where the branching starts(shown in second photo). Is this normal? I don’t think I’ve seen any of my other maples do this, but I’ve never had a Japonicum.
Hello. Not normal, I'm afraid. Your japonicum has had a big stress, and that has proved too much for it. Some structures beneath the skin (xylem, cambium, phloem) are dying, which is causing the blackening. (We often just say cambium, which provides the cells for the other two and enables the bark to grow). These structures govern flow of water and nutrients to the leaves -- winter reddening can often occur as the sap descends for dormancy -- and sugars to the roots, so the tree can't live without them. I don't think this is verticillium, I can't say what's causing it, so I hope maybe someone else will chip in. I've seen heavy overfertilization with associated root burn cause these symptoms. Or even improper planting, too much water, etc. You can treat it with a pulverization of copper, but I fear it's a goner. Sorry. There's nothing japonicum specific, that part's just the luck of the draw.
Interesting. Yeah no fertilization was done by me. We were very dry till this past week. I’d go check it with my moisture measure every 4 or 5 days and water as needed.
The graft looks pretty low in the pot. You sound like you know what you're doing, but by chance did you check for the root flare, and get rid of the potting soil when you planted? Of course the nursery might have dosed it: I got a few maples in about a month ago, I'd swear the soil was 50% osmocote granules.
On this one I don’t recall checking for the root flare, just planted at the depth it was potted in. I’ll have to check that. Better not be like an inch or two below the soil line. Haha
Heh. Yeah a different batch, all JMs, there were some that were easily 3 inches high. The roots had grown upwards, so I actually had to remove root mass to get them to the right level. It was from a good nursery, but I guess that whenever the bare root understock came in, it was potted up by temporary help.
Took a look and it seems to be ok as far as the root flare goes..? It wasn’t too far below the soil. I can actually see what I think are feeder roots right there at the top along with a thicker root barely exposed above the dirt, I guess rain eroded some dirt there to expose it because I don’t remember seeing it when planting. I’ve included a new photo, not sure if the roots I describe are as visible in the photo as they are in person.
Yeah, I can't really make it out, the label blocks the view a bit, too. But it's a dire photo: that immediate blackening above the graft union, and right down into the V, makes it look as though the whole graft is just rejecting. I'd think for it to do this within a month of purchase would justify either refund or replacement. I'd try contacting the seller to see what they say, because I don't think it's going to recover, sadly.
Yeah, I contacted them. I appreciate everyone’s input! Everyday is a chance to learn something new. :)
@Aspen21 : If the tree had no black spots when you received it the chances that it got sick after you received it is rather high and I don't think that the root flare might be the source of the problem. Just the other day a friend asked me about an online order he was planning to make. I told him that now, when I receive trees I always take photos when I open the package so that, in case of any sign of disease I can show that the tree had the beginning of a problem when I received it, because of a previous unpleasant experience.
