This summer has been particularly sunny and hot in my area. We have had daily highs above 30°C (86°F) for 90% of the days since July 1st, with many days above 35°C (95°F). It has been a testing time for Asian maples. I would like to share the extraordinary behavior of Acer shirasawanum 'Johin' which is shown in the first two pics. It is in a wooden pot and is exposed to full sun all day next to the swimming pool. It has taken this heat and sun without any signs of leaf scorch whatsoever. By comparison I am showing Acer shirasawanum 'Jordan', also in full sun but planted in the ground, the leaf scorch for this reputed sun loving cultivar is quite obvious. Based on this experience I would give a top rating to 'Johin' for sun and heat resistance. Most other cultivars in pots had to be moved to a place with afternoon protection because they were showing signs of leaf scorch, including 'Emperor I' for instance. Gomero
Yes, I'll echo Alex' comment. I will certainly add Johin to my garden. The species A. shirasawanum did very well for me this year, during the many days of ferocious sun, both in a pot and in the field. I expected the water constraints of being newly planted (this spring) to be problematic but it came through with flying colors, no more burnt than a well established A shirasawanum in partial shade. I have a healthy young graft of Jordan, in afternoon sun most of the summer but now moved to shade, which looks just like yours. Curiously a very young 'Aureum' didn't burn nearly as much as 'Jordan'. A relatively large 'Autumn Moon' did quite well in the sun all summer, with the fantastic color this cultivar gets with lots of sun. As this one is scheduled to go back into the ground this fall I've moved it into the shade for a de-stress period though, the outer leaves were getting a bit bleached looking. -E
Emery, I agree with your assessment on the species A. shirasawanum , I have one planted in the ground in full sun all day (next to a Fremontrodendron!) and has never shown any scorch. I am also very impressed by their drought resistance. If we remain with the species, I have found that, in my climate, A. shirasawanum and A. palmatum show a remarkable heat, sun and drought tolerance. Other Japanese maple species like: A. amoenum, A. amoenum var matsumurae, A. sieboldianum, A. tschonoskii,...show significant leaf scorch if planted in full sun. Gomero
I find the coloration of Johin to be much more impressive when exposed to more sun. Now I live in the north so our full sun is not as intense so I have never seen leaves burnt on the Johin I have owned. I find the tree to be best in a garden as a shorter tree. Sometimes during the summer the coloration can go to a olive green which has people pass by without noticing it but come fall it is outstanding. My one is currently going to fall color so I will add a photo of it.
Not alaska but it felt like it this year. i have an Acer japonicum 'Otaki' which went from its spring peach color to its fall red/orange in July. you can see the colors in this video http://www.youtube.com/watch?v=4LymWPRixKQ My second garden is not as far along in fall color http://www.youtube.com/watch?v=I13xQxOIsq0 My one garden in is a micro climate different than most since it is very close to the Puget Sound (cold saltwater). I do not understand why there is so much difference between the two location but i can say that the one by the water stays warmer but cools off faster at night with teh cold air off the water.
Amazing colours ;-) Thanks for sharing - but my bank account won't thank you: this makes me feel like adding new ones to my small collection!
oh, I try and close my eyes when i look at all the financial commitments I have made in getting these trees. Since 2007 I have purchased over 2800 japanese maple trees. 150 are planted in my two gardens and 700 are in pots. The remaining trees are in other gardens or the burn pile. Then there are the conifers. On the note of johin, it is a great small container tree.
Fall color starting here too Gomero, with trees that are stressed by drought and sun. I'm surprised you're not seeing some too actually. I find sieboldianum does well in full sun here, but obviously that's not the same as Toulouse sun! I also don't water these plants once established, which maybe causes less transpiration. Sieboldianum gets reddish undersides to the leaves which is very attractive in a breeze.
In Rome not see again fall colors only "dry"colors:) however old maples are without burned leaves Akane of course is only with reserve buds ...no one leaves is on branch.
Not at all, the first maple fall colors I see here are mid-October and the peak is in mid-November. Sometimes, under drought stress, some trees lose their leaves earlier (like Alex's), however I would not label those ugly, shriveled, brown leaves 'fall colors' Gomero
Gomero, thanks for the sharing. I put it on my list for this automn. Is palmatum Johin from Esveld the same plant ?
FWIW I'm not talking about shriveled brown leaves, but large sweeps of yellow in the silver maples, and red and orange leaves in negundo 'Senstation'. (Some tattered brown leaves too, of course). Christophe, Esveld guarantees all trees as true to name, so if it's not really Johin you have a legitimate complaint! :) -E
I am not familiar with Esveld's plant. Mine comes from the U.S You would have to complain Very hard... Gomero
well based on this I would say the Johin is a US tree. Acer shirasawanum 'Johin' Johin Full Moon Maple Plant Description A compact upright deciduous tree having plum-purple leaves with prominent light-green veins in spring. Fall color is orange-to-red. An elegant addition to any landscape. Name means "elegant" in Japanese. Prefers sun/partial shade in well-drained soil. 6' tall x 4' wide in 10 years. Hardy to -20 degrees. USDA zone 5. Discovered and introduced by the Flora Wonder(tm) Collection of Buchholz Nursery
Yes !im one follower of Talon s blog, i ask this,maybe is one hybrid between palmatum and shirasawanum ?
Yes Alex, it is very likely a hybrid. Leaves are not typical A. shirasawanum leaves. I believe that most A. shirasawanum cultivars in the trade are hybrids. To be fully correct, if both parents are not known for sure, it should be named Acer Johin Gomero
We are seeing the start of early fall colors here too. But we had a pretty moist growing season, followed by a couple of dry weeks in late July that lead to a very cool start to August. We usually have overnight lows in the 60's, but we had a couple of weeks with highs in the 70's and lows dropping into the upper 40's. This is weather that is common for late September and October, but not August. The cool sunny days, followed by cold nights, brought out hints of fall colors in many varieties. The first to show it was the japonicum (aconitifolium and Green cascade) Some varieties were unaffected, but others like Koto no ito are putting on a pretty good early season show. Now the heat and humidity are back its leading to powdery mildew outbreaks on a few problematic varieties in my collection, a couple will defoliate if left untreated. Back on topic.. Acer shirasawanum 'Sensu' is one that stands up to heat and full sun too. I have two growing as bonsai and they bake away all summer in full sun, with no wind protection, and look great (which says a lot, since the pots are only 2-3 inches deep). They also did great last summer which was one of the hottest and driest Summers on record. 'Sensu' is another "Discovered and introduced by the Flora Wonder(tm) Collection of Buchholz Nursery" both of mine came from Buchholz as little 3 gallon size in their assorted maple program. With my experience with this variety, I now I wish I had a 10 gallon for the patio or landscape instead, and maybe 1 as bonsai.
Yes, slow growing here too and even slower as bonsai. The tree is in it's thirds season (second season as bonsai) and the distance between leaf pairs narrowed from 1.5" down to .5" as bonsai. It put off 3 new pairs of leaves this season in new growth measuring only 1.5" of total new growth. The leaves have reduced their size by about half in this short time too. I find it so interesting how well these beautiful trees adapt to their growing conditions in just a couple of seasons.
Is this thread out of place? I didn't find it in the Acer shirasawanum section of Maple Photos. I found it through the search option.
