While a group of us were hiking in Red Buttes Wilderness last weekend, we were talking about the range and introduction of species. Japanese maple came into the conversation too. I have never seen a Japanese maple growing in the wild in our area yet. On the other hand, I have not seen a Butterfly Bush growing in the wild, nor in a landscaped yard as a volunteer. But I have seen Japanese maple seedlings in landscapes, as many as 200 under a single tree. Has any area along the west coast ever had a problem with Japanese maple moving into wild forested areas, or parks? Has anyone ever seen any Japanese maple volunteer trees in a park or woodland area? The one below in the photo is a 3 meter tall Japanese maple that sprouted in a Portland landscape be beneath some weeping Japanese maple limbs. There were a few other volunteer trees between 8 and 24 inches tall too. Its just so common in landscaping, I'm surprised to have never seen on in any forested area.
Not seen any in Britain either. Oceanic west coast climates are probably not right for its successful naturalisation. I'd more expect it to happen somewhere on the US east coast, somewhere like New York or Washington DC, where the climate is more like the Japanese climate.
Yes, seedlings appearing in numbers in gardens here are liable to be getting some summer irrigation or responding to other modification of the site. Any popping up in the wild would have to survive the summer climate without assistance. This barrier is so consistent that the tree does not even appear in Wild Plants of Greater Seattle - Second Edition (2008) - even though A.L. Jacobson lists 7 other maple species he has seen coming up in varying states of wildness there (including the closely related vine maple). There has been for some years a tree of some size in the I-5 median just north of the Nisqually Delta that appears - from a speeding car - to be a Japanese maple growing outside of cultivation. It is on the edge of an open place, that might have been used as a staging area at one time. So, it is possible it got heeled in there during highway department operations and never removed later. Stock beyond the seedling stage is less vulnerable, this one - if planted by man - might have even been installed when several feet high, on what turned out to be a favorable enough site for it to persist and develop.
Just a few quick thoughts - interesting topic here. Years ago I thought it was possible for palmatum seedlings to be found in the wild but am not so sure what I've seen in the past were not transplants or had some man made help along the way. I've seen palmatum seedlings in some parks but not in wooded areas as of yet. I suspect some naturalized seedlings can be found in some areas of Oregon but I also feel that a parent plant cannot be too far away due to seed dispersal limitations. Palmatum seedlings just do not get wind dispersed very far from the seed bearing parent. We do not see seed dispersal a mile away from the source like we can with some other Maple species might and in some cases do. It might be novel to try to disperse seed on our own in naturalized settings and see if we cannot have a tree develop over time but we are indeed limited here in California as to where we can attempt to do this and pull it off as too many variables such as climate, soil temperatures, salt or even acid imbalance in our soils and soil borne fungi may prevent the seedlings that do germinate from ever becoming a a juvenile tree. One constant is that the newly germinated seedlings will require a steady, uninterrupted, supply of water when young. Thus parks such as Golden Gate Park in San Francisco is more apt to be conducive for seedling germination than any park around here will be as we are forced to supplement water during a larger portion of the year than some Northern Coastal and inland Coastal areas will. The tough part is how to get these seeds to germinate on their own and sustain themselves on their own without our help in some way. Even a park near me here that does have some Acer palmatum seedlings arising near parent trees still has enough supplemental water through sprinkler irrigation year round to better sustain the seedlings. Without the permanent water, I doubt those seedlings could have lived very long after the seed germinated. I'll add that I knew of two foothill nurserymen that wanted to naturalize palmatum type seeds in remote settings hoping to succeed but I felt then and warned them that they probably could not fulfill their wish without them giving their seed sown and later germinated seedlings some added water, give them a drink, at intervals during the warm and dry Summers. I'd like to say these two men were successful but for many years it was a "pipe dream". If we had 50 years to work on it we might become successful but still it would entail us to baby the first plant along and hope that we can get enough viable seed from it and successive trees to get a stand started and be sustained. Then see if we can get better seed dispersal in distance from then on. Even East Coast seedlings were dispersed by man much of the time but it was also known that some seed bearing trees in let's say Maryland could have their seed collected and then sown in Pennsylvania or North Carolina and see some of those seedlings survive to become naturalized trees after that. Jim
I doubt you would see any naturalization here in the South as we are prone to summer droughts as well. A few years ago we had one that stressed and killed mature oaks and hickories, which are deep-rooted and adapted to those conditions. A Japanese Maple would have no chance unless it had the luck of growing near a permanent water source like a spring or lake. Northeast or the Smoky Mountains would be the most likely spots for naturalization east of the Mississippi. And as was mentioned - how would the seeds get to these ideal locations? They don't seem prone to wide dispersal.
Tree has the limiting combination of needing soil that remains moist yet drains very well. Many cultivated examples become visibly distressed on local sites during summer. This does not, however prevent the species from being one of the most common in plantings here.
Well just stumbled on this thread following some other posts....... and I would not be so sure these days, that JM's wouldn't naturalize here along the 'northern left coast'.... in a sheltered area, receiving typical coastal rain, quite possible.... too the point of being invasive, well not so likely...... I have not seen any as of yet...... but with increasing landscape plantings, the wind born seed has potential for striking a suitable site...... and I have seen prolific germination of Acer palmatum, in poorly irrigated local landscapes.... I had rarely seen escaped Buddleia sp until a couple years ago...... but have now seen dense patches competing with willow on gravel bars along the Middle Fork of the Willamete River.... It appears to be a dwarf Nanho Blue strain, which I think comes from crosses of the numerous hybrids..... I have mostly seen it seed in gravels along roads, RR tracks, and now gravel bars...... and of course Cortaderia sp have found their liking in the coastal clearcuts.... As for the stray JM plant noted above, along the interstate.... that could be Acer circinatum 'Monroe' on close inspection..... I have seen wild seed grown varieties of this, that I could not tell from a 'dissectum cultivar' of Japanese maples.... wheter Monroes are just relic gene expression, or perhaps hybrids???..... from outward appearances hard to tell.... anyone seen any genetic analysis??
Small seedlings abundant in cultivation here, larger, persisting examples of clearly spontaneous origin not so much. Buddleja davidii is not a woodland tree, it is natural for it to come up in disturbed or barren places. And it produces vastly more seeds per shrub than Japanese maple.
This 3' maple that i just transplanted, i found growing in the woods, here in Maryland, a good 200' feet from the supposed parent tree. http://www.botanicalgarden.ubc.ca/forums/showpost.php?p=273404&postcount=1
Different climate back there, much more like eastern Asian homeland. Some of the most vicious exotic weeds in eastern North America originate in eastern Asia.
Yeah Ron Buddleja sp more a shrub, and I have several relic plants about 10-12 years old, that likely produce abundant small seed, and they seem to prefer that moist gravel mulched seed bed to get started, ......and they have rarely seeded in my crushed gravel driveway....moisture and bed likely critical..... as on the river gravel bars whereas for the Acer palmatums... I find prolific seedlings in bark mulch surrounding the parent trees, in poorly irrigated landscapes--as likely watered by our NW rainfall as by irrigation.... most of these in the understory of the parent, .....but will admit have yet to find many made it thru the season.... due to nature or landscape maintenance hard to say...... So Weedbender, what was the water supply for that volunteer, and the groundcover...... yeah I have little doubt it came from the parent 200' away, a good gust will do that.....and in fact our native Acer circinatum has virtually the same plant and seed structure as A. palmatums.... usually the samara is slightly heavier in the A. circinatum cotyledons in my experience....... but in fact much of the A. circinatum in the wild seems to propagate from layering by snow loading, or suckering, generating the dense thickets typical to species..... I suspect many seedlings are starved for light, as much as any other factor...... as they propagate well in the open nursery environment.......yet not even in the well watered thickets have I seen many seedlings........ Maybe someone has or will do a genetic comparison of the two species... be interesting to see how altered they have become, they may in fact still cross...... and surely there are a number of relic genes in A.circinatum just waiting for Vertree's successor to come along...... The real shame is the hundreds of selected varieties Vertrees developed, go largely unknown in the landscape industry...... most landscape architects have no clue what a 'linear lobe' maple variety is......... Another tectonic divide of sorts........
Jimmer Ground where i found it is leaf littered, not marsh. Sandy/clay soil. Its been very dry last few summers. But I can dig 5' and hit water any time of year. I found a whole bunch of very small volunteers in my yard this morning : )
Hey Bender Yeah that sounds and looks like pretty ideal seedbed.... that sandy clay probably encourages root development, while the clay retains moisture as the surface starts drying..... and with that water table at 5', sounds like it gets a constant supply of water once the roots get some depth..... yet still getting air in that drier sandy soil...... In the nursery we like to forego watering just to the point of leaf collapse, that really encourages the plant to drive deep roots..... sounds and looks like you have an ideal spot to encourage good root development, and a steady supply of water once the roots get some depth....... and at the same time looks like nice filtered sun in that tall light overstory...... Yeah it'd be interesting to coddle that progeny, maybe in some containers or a tended bed, and then plant them out this fall.... see what variations you get.... I don't know if A. palmatum is self fertile or needs another to pollenate..... think self fertile, as my atrolineare has started a bunch of early seed, while I had it tucked under the house this winter, in isolation, so maybe self fertile... we'll see if produces any viable seed..... I don't have any other flowering maples on my place, but I suspect there are plenty of wild big leaf, A. macrophylla, and vine maples, A. circinatum, on the hill above me.... doubt the macrophylla crosses with palmatum, but the circinatum just might.... Curious aside... I found a fella tapping our native A. macrophyllum for maple syrup a few years ago..... never thought of any maples other than A. saccharum as source of maple syrup...... he said not quite as tasty as traditional A. saccharum, but still sweet....... when you get a grove of A. palmatum in your old age have to see what they produce!!! The largest A. circinatum I've ever seen had one trunk about 6" caliper... possible..... but the older A. macrophyllum here have 4-5' diameters, some maybe close to 10'...... later
