Gil, I have never seen an Acer pentaphyllum in our country so I have no idea about its waking up in spring. My seedlings passed their first winter indoor. You are probably right about its low vulnerability but in the meantime I cannot confirm it for our climate. Are your trees of A. pentaphyllum grafted? Ota
Ota, Mine are grafted. This is my second year with them. So far they are slow growing, about 8 inches of new growth per year and both get a bit of leaf spot or mildew. Overall they are holding their own and I think still settling in. I think they leafed out about about 1 month later than palmatums.
As I explained in a separate thread (Sam's dead 'Kasura' thread) my established A. pentaphyllum just passed away. It was grafted and the understock (A. platanoides) is now alive and well. I have heard of other people who have suffered similar fate. I am wondering about long term compatibility with the rootstock. Ota has been lucky to find seeds. Maybe other grafted trees in US or Europe have also given viable seeds. Does anybody know if this species is being proposed by some growers (US or Europe) as plants grown from seeds? Also, which would be the best understock?, from the Quarryhill article one learns that T. Domoto was very successful grafting them to A. saccharum, other experiences? Gomero
Dan, Maybe we should continue the discussion over here so it is easier for future consultation. What you say is interesting, I reckon that my pentaphyllum died of 'delayed graft failure'. I am not very familiar with that and I , like you, am wondering how prevalent it is. I agree that A. platanoides may not be the best understock for it. By the way, how did you get a seed grown pentaphyllum? Gomero
I lost a grafted pentaphyllum this spring. It was one of a pair I planted in 07. The rootstock came out swinging after the scion part died. I asked a question about its ID in this thread.
My acer pentaphyllum is 20 years old. In Australia they grow well though they are always one of the last to come into leaf and to change colour in autumn. Mine has had fertile seed for many years with seedlings germinating everywhere. I have attached a picture of the tree with some of the seedlings underneath. About 60% of seed are viable and in most seasons the tree is covered as shown.
Some Acer pentaphyllum seedlings grown over winter under lights, seeds from the southern hemisphere (thanks to a generous Australian). First plants germinated at the beginning of December, and after less than three months are over 30cm tall. No additional seed stratification was employed, as the seeds had already spent the Australian winter outside on the ground. Seeds were soaked for 24 hours at room temperature and planted. Germination has been about 50% so far but seeds continue to sprout occasionally, including two in the last week or so.
Cor, I want... ;) Any chance of popping one or a few in the mail at the end of the season... seeds would be awfully welcome too. I have one grafted penta still going, but feel as though I'm skating on thin ice. Nothing like seed grown, really. -E
Those are some big seedlings! I bought a seed grown one last year from Forest Farm in USA, west coast. So far it hasn't seemed to be fussy, fairly easy to grow. Would you agree? Kay
I received young plants of this species from a French supplier this year, the seed coming from Australia. Because I was unsure about its hardiness, I tried to find some more information. What I found out is that there is a tree in the Botanical Garden of Frankfurt/Main in the Western Part of Germany, near the Rhine Valley. The small plant suffered from frost damage several years ago but was replanted at another site where it withstood the last winter without damage. Frankfurt/Main is in Zone 8a, with temperatures normally not falling below -10 to -12 °. However, last winter saw a more than two-week period with permament frost down to below -15°C. So - together with Gomeros observation - this seems good news regarding the hardiness of this beautiful species!
Most, if not all, pentaphyllum seedlings commercially available come from the same adult tree growing in a garden outside Sydney ;-)) Interesting information that will increase our knowledge on hardiness of this endangered species. I know that in the UK it has suffered, and died, with temperatures below -18°C. Gomero
I have Acer pentaphyllum It is 35yrs old. Grafted onto what I do not know. It is higher than the house and about 15m wide. Autumn colour is nothing tho' I believe more recent selections are much better. It seeds heavily every year and numberless seedlings germinate every Spring. I have noticed this year that some appear to be coloured, and a few very bright red and bronze shades. There are several other mature *** maples nearby. Could hybridisation occur? Many years ago I sent large packets of seed to Homestead Division nursery at Chesterland, OH. I know they germinated well but I'm not sure what happened to them. As that nursery specialised in Hosta the seedlings may have been sold on. The owners had lots of connections with big nurseries around Kalamazoo.
Xerious, I would love to see pictures of such a large Acer pentaphyllum if you have any; would it be possible for you to post some on the forum please? I don't think it would be possible for A. pentaphyllum to hybridise with typical Japanese maples such as Acer palmatum because they are not very closely related. It might be possible with more closely related species, such as Acer buergerianum which is in section Pentaphylla, but I do not know for sure.
maf, Some pictures of a 12m (approx) tree in summer and a range of seedlings showing autumn colour. Unfortunately the larger trees don't colour as well. They are however sun tolerant and develop a weeping habit which always creates comment even from non-maple lovers.
Simon, that large tree looks amazing. Interesting to see the form it develops as a mature specimen. Acer pentaphyllum seems to be only marginally hardy grown here in the UK, at least when grown in containers. Out of a dozen or so seedlings I lost all the small and weak ones the first winter and then a couple more the second winter, leaving 4½ of them alive as of June 2013. They are very late to leaf out and following this year's late spring in the UK they did not even start leafing out till late May and are still not fully leafed out in mid June. I may try overwintering them in a greenhouse from now on. One question, do the seedlings and young plants handle full sun OK? I have been growing them in a fairly shady area but I am thinking of moving them to full sun in the hope of improving the growth rate.
maf, Yes they do. In front of the picture of the large tree is a seedling that has been growing in an area in sun almost all day without any shade including last summer that hit 40C. Not even any leaf burn. Even small seedlings tolerate the sun, the narrow strap like leaves may help protect it from water loss. They are late in leaf but also late to lose them in winter. The seedlings and large plants still have leaves going into winter but are last into leaf (mid November) in Australia. Your seedlings in shade, is the ground wet? They should survive even in shade as most of the seedlings sprout and survive amongst undergrowth. Their natural range is a steep slope so they may not tolerate water logging otherwise I don't know why they are dying. Simon
They are indeed very late leafing out this year. Even here in Southwest France about half of my 10+ seedlings are just barely breaking buds, quite unusual. Gomero
Thanks for the info re sun exposure. Will definitely move them into more sun this year. I am almost certain that the losses I experienced were due to winter cold. Talon Buchholz claims that Acer pentaphyllum is reliably hardy only down to 10°F (-12°C). We have had some cold winters recently and have experienced temperatures almost that low. Some natural variation between seedlings is a good thing and hopefully the ones that continue to grow are the strongest and most cold hardy; the least cold hardy having been weeded out by mother nature.
this is mine,is 5 years old,graft on platanoides is high 2.50 m, grown arouund 30cm/years.have a very good tollerance to clay soil and after 4 years good resistence to hot temperature (over 40°)but again the leaves in autunm are off without good colors.
http://www.bgci.org/files/Worldwide/News/sepdec09/maples_red_list.pdf this is the red list how Ron B write in first page Acer pentaphyllum is in this list