I have grown this maple for eight years now. It was sold to me as Songo kaku. It has the bright red stems on young growth as expected, but growth is much less vigorous and in the autumn/fall it turns this pale bright lemon colour unlike other Songo kaku I have seen. Any ideas?
It should have been 'Sango Kaku', or less often 'Senkaki'. I think I read about a slightly different cultivar, but I'm not sure. Anyway, the yellow colour is what the leaves on mine and others I've seen here look like in autumn. Maybe a grafted tree from slightly different parent trees in different parts of the world?
As you say, maybe grafted on a less vigorous rootstock or weaker growing parent trees. This is my other Sango Kaku which is younger and more orange at this time of year. Thanks.
I've heard that, like in Brittany, it only rains twice a year in Ireland: from January 1st to mid-July, then from the end of July to Decembr 31st. OK, bad joke, but here it's been such a hot, dry summer. My potted 'Sango Kaku' was kept in the shade for most of the day, watered every day, and it's just beginning to show a pinkish colour before turning yellow:
Ken, it does look like 'Sango kaku' to me. My experience is that plants kept in more shade (or as in your second post, interior leaves that are shaded by outer leaves) tend to be more lemon yellow.
Through a variety of acquisitions I have four trees which are Coral Barks. Three of them had Sango Kaku tags and one was misidentified as a Higasayama. They all have different forms and coloring. I love them for their leaf color throughout the seasons and ability to handle full sun. #1: The first (and best) was purchased 11/16 and was glowing yellow when I got it and turned orange later. (See my avatar). It's vase shaped and densely branched. It's the only one that has shown significant fall color so far. Of all my JM's this one is my favorite. #2: The second I bought 11/17 and it had a Higasayama hang tag. But it has red bark and Sango leaves. It's mostly columnar. No color change at all yet. It's the only one planted in ground and gets the most shade. #3: The third I also bought 11/17 and it is tall and leggy with bright red bark. Leaves seem to be getting lighter. #4: The last one I just bought a couple of weeks ago and is vase shaped and very dense. Doesn't have obviously red bark. It was the last Japanese maple of the season in stock at a local nursery. So I can't speak to how it was treated. Leaves have some sun scorch but seem to be turning yellow. I've been trying to find out what the misidentified one was because it seems to be very different. I found information on line that indicated that there are several varieties of Coral Barks and I suspect many of them are identified with the generic "Sango Kaku" name. There are Aka Kawa Hime, Beni Kawa, Eddisbury, Winter Flame, and Sango Kaku cultivars all Coral Barks with descriptions that are very similar. I took pics today for comparison:
