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Leaves will probably drop next week. I love this beautiful GGW I have been raising from a 1gal.

I’m new to all of this, got this cultivar last month and repotted. It’s been a couple of nights that the temperatures dropped to 34-36F. I’m impressed how tough this little thing is. I hope to make through the first winter season.

Hi everyone. Just showing off a bit even though there isn't much to show yet, but I'm excited anyway. I recently got an Acer shirasawanum 'Moonrise', my fourth Japanese maple ever and the first one in quite a while. After some international travel from the Netherlands to South Africa she's taking a bit of a break from growing, lost a few leaves and is hopefully currently gathering her strength for new leaves and growth. 26 days since planting, and she will be the focal point of the little terrace area.

Zone 5 east coast. About 13 feet tall. Taken Oct 27 2026.

Since May I’ve been volunteering at a local nursery (Mid-South, humid, Zone 7b/8a). One pattern kept showing up this fall is that powdery mildew appeared on the red dissectums first, then moved to the green laceleafs.

The ones I noticed first: Inaba Shidare, Tamukeyama, Red Dragon, and Crimson Queen. After that, the green laceleafs nearby.

To be clear, it hasn’t been a problem at the nursery. It’s managed with a proper spray program. I just think the pattern is interesting and want to hear whether others see the same thing.

I got my hands dirty and did some research and I don’t think “red laceleafs are more susceptible” is the best explanation. Here are the explanations I think are in play, from most to least likely:

1. Canopy shape. Powdery mildew is unusual among fungi because it doesn’t need water on the leaf to infect. It likes high humidity, shade, dense foliage, and still air. A weeping dissectum is about the most mildew-friendly shape a maple can have, a thick mound of lacy leaves draped over the pot with humid stagnant air trapped underneath. Sources specifically note that the disease favors lower plant parts and dense foliage, which matches where I’ve seen it start.

2. Red leaves make it easier to see. White fungus on burgundy is high contrast. On green lace, the same infection can be there and go unnoticed. This has been noted in other plants with ninebark, purple-leaf cultivars get mildew but are rated resistant and the disease is described as more noticeable on purple foliage.

3. Sample size. Those four are some of the most commonly grown red dissectums, so any nursery has a lot of them and they’ll show up first in anyone’s observations.

4. Proximity. The nursery tends to group dissectums together. The green laceleafs have the same dense-canopy microclimate and sit right next to the first infections.

Evidence against the “red = more susceptible” idea - In a Wisconsin outbreak on Norway maple, the dark-leaved and variegated cultivars were barely affected while the green trees were hit hard. That’s a different maple and a different mildew species. So, it doesn’t settle the question for Japanese maples, but I couldn’t find any research showing red palmatums are more susceptible.

On fallen leaves in the pot - Some of the affected trees had leaves sitting on the soil. I first thought that was the cause, but I now think it’s mostly a sign of a dense, low canopy rather than the source of this fall’s spread, which travels through the air. Leaf debris matters more for next spring, since the fungus can overwinter on it. So, cleaning up fallen leaves in fall is still worth doing.

Why now: Mid-South fall is ideal for powdery mildew. Warm days, cool nights, and heavy dew are exactly what it needs.

What I’d like to know from you all

• Have you seen red dissectums get mildew before green ones? Or green uprights before red uprights?
• If you have red and green laceleafs side by side in the same light, which one gets it worse?
• If you check the lower leaves and undersides of your green laceleafs when the reds first show symptoms, are the greens already infected?
• What’s your climate and humidity?

Sources:

Clemson - Powdery Mildews

University of Arizona - Powdery Mildew

PNW Handbooks - Ninebark Powdery Mildew

Plant Disease - Sawadaea tulasnei on Norway Maple

Connecticut Agricultural Experiment Station - Powdery Mildw of Woody Ornamentals

The first of my Japanese maples to put on autumn color.

I often take a walk on the local cemetery (Zurich, Switzerland) and they have a substantial collection of Japanese maples － star shaped, linear, dissected, hundreds of different colourations... you name it. But one of them seems different to me.

While the tree itself is about 4-5 m/13-16 ft tall, the leaves are smaller than those of the others (maybe 4 cm/1.6 inches; I have very small hands and fingers btw) and very feathery with a noticeable overlap between the individual lobes. Almost reminds me of certain types of ferns and there's a smoke-like quality to it from a distance.

The foliage is medium green throughout the summer months (last picture) and turns into a nice coral red towards the end of September.

There's a dozens of lacy and serrated cultivars in this garden but none like this and I've never seen a similar one in our local garden centres either.

I would be grateful for any lead!

Starting to colour up nicely after finally some warm weather in Melbourne. Pink days ahead!

I almost forgot to take JM photos before the rain this weekend, that we definitely need in the PNW

Hi, fellow japanese maple enthusiasts. I'm here to ask for some advice.

My 'Shishigashira' has grown too large for it's container (honestly it's overdue), and I want to free it from it's prison, this fall.

I live in Denmark.

The soil where i live consists of a thin to medium layer nutritious top soil, and beneath that it mainly consists of clay, that gets more compact the deeper you go. The clay goes from red, to very compact blue.

How would you go about this, to ensure that the tree has the most optimal start?

This is how i considered going about it:

- gently smash the container to free the tree - hose down the rootsystem and untangle as best i can - dig a hole roughly 3-4 times larger than the container in surface area, and 2 times as deep - mix the clay with 50/50 hummus, and fill the hole halfway, before plantning the tree, and filling in the rest, while making sure to not compact the soil too much - lastly i would put down a thick layer of woodchips, while also making sure to keep a small distance to the stem, as to not suffocate it.

Thanks in advance!

It is not easy to get foreign origin varieties in Japan. "Atropurpureum" is a frequent topic of this subreddit. I purchased it last summer. I noticed that when it is grown in the shade of summer, its beautiful leaf veins become clearly visible. Unfortunately, they did not appear this year. I will try again next year.

Hi, i got this grafted tree back in spring, it's been repotted 2 times this year and is this a good time to get these to ground?
PNW zone 8b

Winter season with expected temperature of 0 - 5°C is expected soon in my region. Based on my research, this will be the time to do my first major pruning on my plant.

About the plant:

• I purchased it around May, so this will be it's first winter.
• The summer heat and my recent negligance caused many branches to have many brown leaves and some even to be (almost or completely) bare. In my case, bare means that these branches are still alive.
• My plan is to have some kind of Y-shape with two major direction of growth.
• It is placed on a North-eastern , so between March and October it receives direct morning light. (I didn’t rotate its orientation at all)

How would you approach the topic of pruning in my case?

• I’ve read that you shouldn’t remove more than 20% of it's canopy at any one time. Does it also apply to my very juvenile acer as well? (I imagine the 20% less than necessary to achieve the expected shape)
• Also, canopy in this context means the total ammount of bare branches without the fallen leaves, right?
• If you have some free time on your hands, I would appreciate to receive some ideas edited in Paint or anywhere else showing what you think would be the best places to make the cuts.

Please also let know if you wish to receive further pictures for a decent analysis!

Thanks in advance!

After seeing an earlier post, I learned about these beauties! The are delicate and upright, which is ideal.

Adding 1-2 of these would be wonderful additions to my landscape. I have some other Japanese Maple (planted in the 70's, with volunteers placed thoughout, along with other red, silver, Amur, ect. that would blend sooo well with the Seiryu.

I'll pay more attention to nurseries for this variety. Are these common or hard to come by? Are they difficult to propagate? If anyone can offer up something or a US source for small starters that would be super appreciated.

I planted a 15 gallon container mikawa from Iseli nursery in the ground today(Massachusetts zone 6b). The tree still has all the leaves. The root flare is exposed.

After exposing the root ball, I scraped the roots gently on all 4 sides with a hand cultivator tool and then planted the tree. Pics of the root ball shared.

I did NOT root shave 1 inch on all sides and bottom of the root ball as I have read some instruction to do so.

From my limited experience, I would say the tree was root bound. The soil was not crumbly and quite compact and dense.

Did I make a mistake by not root shaving 1 inch on all sides and bottom?

1. I can dig the sides out and root shave it tomorrow. Should I do it? I was reading that if the tree has all leaves intact then it should not be root shaved all the tree would go in shock and there might be die back. Also it might be too late in fall for the tree to recover should I root shave now. The new roots might not establish before the winter. So root shaving now is a bad idea?
2. should I wait and dig it out and root shave late winter/eRly spring? I am reading that might be the right time to root shave? Would it be ok to dig the tree out of ground and shave roots then?

Or should I leave the tree alone as I have planted it by just scraping the outer roots gently?

does one of these root need to be cut?