We have a seed-grown 'Bloodgood' that is on a well-amended mound that has about 8" of mulch protecting moisture loss. It is underneath an Austrian pine on the north side of the house, gets about 3-4 hours of sun and partially protected from prevailing winds by a fence and neighbor's house.

Even with all this, we lose about 15% of the branches each winter and the infamous bunnies have - in desperation - nibbled the trunk for nutrition, weakening the tree (albeit some dim-bulbs up the street are practically feeding them in winter so bark munching is avoided as long as they continue).

Seedlings are tougher, and this is one tough little tree in as favorable environment as it gets around here, and this one is still scraggly. I like it because it is one tough little tree, not because it is beautiful.

Dan

It sounds as if you have a worthy tree, Dan - tough and determined to live.

I have placed them under my spruce trees (protection from sun) on the north side of my yard in a corner with a shed on one side and a 6 ft fence on other (wind protection) plus they were planted on a mound with lots of mulch.... and they still die. The tiny 10" tree is basically in this same area, though not on the mound, and it is still fine (I think it is staying small to hide from all of the bad Colorado things around it.)

The other tree that has survived several winters and actually looks pretty good all summer long is basically protected from the wind on four sides and probably gets less sunlight than the area under the spruces. I may try to plant one in that area except I don't have a lot of room left in it.

The other thing I was considering was trying to grow one in a container; this would eliminate the problem caused by our alkaline soil and would enable me to move it if necessary if it was getting too much sun, etc., but I am not sure how I would overwinter it as I have no garage or basement...

Holly

What I try and do Holly is ensure consistent soil moisture. The mound under the pine was made with much steer manure and some sulfur and also compost, to hold moisture and make less alkaline (we're pretty high pH out here). I'm not exaggerating when I say I put 8" of mulch on the mound. Its packed down now, but still dense. Still I'm not going to cry if it dies, but I will miss the red through the needles.

Dan

Thanks for this discussion. I am considering Japanese Maples for an upcoming garden project. I realize they are marginal for our area.

The Denver Botanic Garden has several nice Japanese maples growing in their gardens.

How cold hardy are they? The place I've been looking at online lists them as zone 6. But surely Denver gets colder than that.

It's good to know that the wind, low humidity, and alkaline soils might need to be taken into account. Sigh.

How cold hardy are they? The place I've been looking at online lists them as zone 6. But surely Denver gets colder than that.
Cold hardiness is somewhat debatable. They really are marginal here, as you mentioned, polygonum. The Denver metro area is in Zone 5 - actually zone 5A for the most part I believe, which is rated at -20 to -15 degrees F. (You can use this site to find out your zone by zip code: Hardiness Zone by Zip code I even use this applet to find out what zone the nurseries are in when I mail order from them so I know what zones the plants are used to before they get to me. Of course, this method lacks in accuracy if the plants have been grown and kept in a greenhouse....)

As for what the Denver Botanic Garden is able to keep alive...well, they have a lot more experienced people to watch over their plants, site their plants correctly and take care of them after the planting than you and I do, but seeing what grows and thrives there does give us all hope of having equal success!

I actually did manage to have one weeping lace leaf cultivar of JM survive for one winter, the Acer palmatum dissectum 'Viridis' (green leaved of course.) There was a lot of die back but I was thrilled. And then it died this winter.

As already stated, the problem with growing Japanese Maples here in Colorado is not just the cold, but the alkaline soil, wind, aridity, and intense sunlight. This is a list of JMs that are hardy to -20 degrees (normally Denver doesn't get that cold): Cold hardy Japanese Maples As you can see, there are quite a few choices of very nice trees, but... 'Autumn Moon' is one that I tried; it died. Others may have better luck with one of these cultivars, of course. When I dug my poor 'Autumn Moon' out this spring, the root area was very dry so I may very well have killed it by not giving it enough winter water - even when dormant, I guess they shouldn't be allowed to dry out....

There is only one JM that I have heard of that is rated to Zone 4, Pseudosieboldianum ssp Pseudosieboldianum, the Korean maple. It has red and green colouring in the spring, yellow and green summer colour and orange, yellow and red colouring in the fall. It supposedly can handle full sun as well, but I don't know if it can handle full sun in Colorado! Anyway, that tree is definitely a possibility; it gets a bit bigger than I want (12-16' tall) but it might just do for others - and I might try it as well. With all of the "anti-JM" conditions it has to contend with here in Colorado, it might not get that big!

Bob - have you tried growing container JMs? Just curious as to what you did with them in the winter.

I do have a sun room that I could put the tree in for the winter, but there is a small heater in there. I have my orchids, non-hardy cactus and non-hardy perennials in there for the winter and they need temps to remain in at least the 60's(F.) I have been told that this might work if the tree is allowed to stay out in the first couple of weeks of cold (pre-20 degree F temps) in order to make it go dormant, but won't it come out of dormancy with such high temps?

Whew. Sorry for the long post; hope you were all able to wade through it!

Holly

The Colo Front Range Tree Recommendation List says A. palmatum more hardy than A. pseudosieboldianum (albeit JMs are short-lived). I wouldn't try any variety with dissected leaves, as the more dissected you get the more sensitive they are, and any variegation will do the same.

Dan

Wow, that surprises me, that palmatum is considered hardier here than the species pseudosieboldianum. That contradicts everything else I have read about hardiness comparisons between the two - not that my reading has been all-inclusive, of course.

Holly

Well, darn. I like the lacy-leafed varieties. I guess I won't waste my money. Or rather, if I do plant one, I'll have it in a large container and wheel it indoors over the winter. Or plant it somewhere very protected and realize that I may not have it for a long time.

Another really interesting maple I saw at the Denver Botanic Garden is the paperbark maple (Acer griseum). I'm definitely going to include that for my gardening project whether or not I try any Japanese maples. The leaf shapes aren't as attractive to me as the Japanese maples. But the bark is very cool and they do seem to have colorful leaves in the fall. Also, they are more cold hardy than Japanese maples. It looks like they too might need some protection from wind and some attention to their moisture requirements.

Since we had an extended period of temps below -15F this winter with under -20F overnight, I definitely consider us to be a solid zone 5.

I own several Japanese Maples and they are all doing great.

I have a Red Emperor, Tamukeyama and Crimson Queen in the south side, protected by a 6 ft fence. A Crimson Queen in the north side -in a corner of a fenced in area and a Tamukeyama facing east but with protection from the winds. All have been thriving. I always add coffee grounds to the soil around them and that seems to keep them happy. I make sure each tree has its own drip & use a tree wrap from Thankgiving till Easter, especially for the first year or two. I also have a Red Dragon -not really hardy to Zone 5- that I overwinter it in the garage.

What about Acer japonicum 'Aconitifolium', the full-moon maple cultivar known as the fern-leaf maple? It seems sufficiently cold-hardy. Does anyone have experience keeping it alive here?

Another alternative is to take that cute little 10" tough JM and turn it into a bonsai!

http://www.wikihow.com/Create-a-Bonsai-Tree

Sadly after about 5 years in the Denver metro, my Japanese Maple succumbed to an early freeze last October/late freeze this April. Not sure which did it in but I'm afraid it's toast. There are around 5 in the neighborhood, I don't see any of them leafing out.

I've given up on JM here, near Fort Lupton. I have 2 Acer pseudosieboldianum x palmatums, Arctic Jade and Northern Glow. Arctic Jade has survived an open north exposure for 5 years. We have open farm fields for miles to our north, so no wind protection. It hasn't grown a lot and had some die back on its leader the first winter but has survived. Northern Glow was planted last fall, just before the October freeze in a more protected, east facing exposure. Neither has leafed yet, but buds look good and the bark is green so I think they made it. I think it's worth trying these hybrids if you want that look.

I had two different ones (Bloodgood and another) that survived for about 3 years and then last year they didn't make it through the winter. It was pretty sad. I do love them so.

One of my neighbors has one and his always looks amazing. He has it up very close to his house on the North facing side. He has it pruned small and wide. I am crazy for it! But I believe my attempts are now concluded.

Japanese Maples can live a long time.

The pic below is one at our previous house that I planted over 30 years ago.

Oh wait, that was in North Carolina.

Never mind.

Very funny, Jerry!