Most JM's will take a lot more sun than you think, many dissectums among them :-)) However, all are happiest with some protection from hot afternoon sun so given the choices, I'd opt for the morning sun/dappled afternoon shade location.

Is this coming from a zone 8/9 perspective? If so it says a lot on how much heat and sun these guys can take.

I never had issues with any tree I've purchased, except a Shirazz a few years ago. I think it turned my wife off to gardening and made me rethink Japanese maples in our yard. But after talking with many of the garden centers around here it seemed almost all of them were lost around here and no one carries them any longer.

Currently, I have

two Emperor I

Autumn Moon

Crimson Prince

Skeeter Broom

They are all doing well and located in full sun or afternoon sun. I will put the Orangeola in morning sun. As I don't want it to burn. Thanks for your response.

Don't equate the zone designations with summer heat - that is very misleading :-) They only reflect the potential cold of winter, nothing more. While I enjoy very mild winters, I also have very mild, cool summers. And I am far enough north that summer sun intensity is low compared to more southerly locations.

Japanese maples are able to grow in some very hot locations and speciality JM nurseries in places like the central valley of California and Texas have compiled lists of heat and sun tolerant varieties, which includes many of the dissectums (especially red leafed forms). But all will state that some midday shade is preferred: "Japanese maples should always receive afternoon shade. These beautiful trees do well in high heat conditions but do not do well in high heat conditions if they are exposed to the Sun's direct rays after noon to 1 p.m. Tree placement underneath a larger tree's canopy or on the North or East side of your house is strongly recommended. "

Nope. It's been in the ground about 3 years. The first year I may have watered it a few times a week in the summer. It had slight burn the first year by the end of the year..... A tiny bit last year, and I suspect even less this year. I'm in PA btw.

I have an Orangeola in full sun in NC near Charlotte. 2 years in ground. I also have 2 Tamukeyamas, 1 Burgundy Lace and an Emperor 1 all in some degree of full sun. I really do not have much shade to plant in. I have had great success with JMs in full sun where I am.

I have one in full sun in the same zone. 5b, bordering zone 6 because my yard is very urban. It handles full sun beautifully.

Later in summer it tends to bronze out, probably from heat?, but in the fall it has one of the brightest, and longer-lasting, color displays of my JMs.

I would not put it in shade-- it will not keep its red color very well in shade.

You never want full shade for anything other than a variegated Japanese maple. But part shade or dappled shade or at the very least, afternoon shade is the preferred siting for ALL JM's. These are not full sun trees - they are by nature woodland understory plants and growing them in full sun is a stressful environment for them regardless of location. Just because you have one growing in full does not mean that's the situation the maple would like best!!

If you put a red JM in afternoon shade in 5b, most will quickly green. Full sun in zone 5 is very different than full sun in zone 8/9. When I talk with nursery owners on the coasts, many of them remark on this, and thankfully their expertise has turned out to be accurate. All but the most delicate JMs do well here in full sun.

My 'Orangeola' has no sun past noon and it stays red. It does affect the vibrancy of the fall color, however.

tj

Once again let me stress that you cannot equate summer conditions or intensity of sunlight to hardiness zone!! This is a very important issue that most seem to be ignoring. Hardiness zones only refer to winter temperatures - they have nothing at all to do with summer heat, humidity or intensity of sunlight. And you cannot make a correlation that higher zones are hotter or with stronger sunlight - this is not a north/south issue at all. My summers are never hot - a few days at 85F or more is considered a major heat wave - and because we are so far north, sun intensity is low. Still, many JM's will scorch in full sun here.

Folks grow all sorts of plants in situations that are not ideal for them. That doesn't mean the plants will die.....only that they may not grow as lush or as robustly or as vibrantly as they would in situations more to their liking, While many JMs can be grown in full sun, ALL will be happiest of out of the most intense and hottest of the afternoon sun. Every JM resource will state that - Vertrees, Van Gelderen, all the specialty nurseries, etc. If one has a choice between a full sun location or one that receives some afternoon shade or even full day dappled or filtered shade, it is strongly suggested to pick the latter.

btw, just as many red leaved JM's will bronze out or green up in full sunlight as others will do in shade. It is a matter of the specific cultivar, not just the color of the leaf that determines that so broad generalities about this are invalid.

Actually, if you reference Vertrees, his Guide to Characteristics rates most JMs as "tolerating ANY light conditions from partial shade to full sun" and rates many as plants that "benefit from full sun."

Vertrees' list of Japanese maples benefiting from full sun (the list of tolerating full sun is too long):

Amagi shigure
Aoba Jo
Aratama

Autumn Red
Beni hime
Beni yubi gohan
Bewley's Red
Bloodgood
Boskoop Glory
Chirimen nishiki
Crimson Carol
Deshojo nishiki
Dr Tilt
Dissectum Nigrum
Edna Bergman
Emperor I
Fireglow
Garnet
Glowing Embers
Green Tropenburg
Hagoromo
Japanese Sunrise
Kiri nishiki
Kogane nishiki
Margaret Bee
Masu murasaki
Matsugae
Oshu shidare
Otome zakura
Pendulum Julian
Pink Filagree
Red Filigree Lace
Red Flash
Samidare
Sekka yatsubusa
Shaina
Shigure zome
Shikage ori nishiki
Shojo
Shojo shidare
Stella Rossa
Summer Gold
Sunset
Taki no gawa
Tennyo no hoshi
Trompenburg
Vandermoss Red
Villa Taranto
Waterfall
Watnong
Yezo nishiki

....and the 4th edition was written before the explosion of new cultivars we've seen in the last 8 years. :)

Yes, straight Acer palmatum is an understory tree. Yes, it likes its shade. But it's no surprise that growers have field-tested many new cultivars that thrive in , and were selected for their performance in, full sun.

Another fyi....he recommends full sun for densely-leafed cultivars like
Behi hime, because it helps prevent the fungal infections to which these
dwarf cultivars are prone. That's definitely been true in my
experience. I keep my shade-loving JMs in shade or part-shade, but in
terms of growing the rest in full sun.... as long as their moisture
needs are met, they thrive.

My orangeola was originally planted in full sun. I moved it to a spot where it got mid-day sun. I moved it space reasons not because of growing problems. The tree did well in the sun and its current location. I'm in Zone 6a/6b

I have 3 Japanese Maples in full sun and they are doing great. I have a Crimson Queen, a weeping green Japanese Maple (Viridis), and another weeping red variety (I don't know the name).

I have two orangeolas that I planted
seven years ago. I'm in a NW desert... zone 7, but it is very hot w/
dry winds here in summer. Hot like... over 90f for months and up to
around 112f. Our soil is in the mild alkaline range. Both trees are on a
drip line since we get about five inches of rain a year. I have not
fertilized, mulched, trimmed or babied them.

1.) One gets morning sun/afternoon shade and is next to our house.
About three years ago, we did a horrible job of transplanting it a few
feet over. DH was certain it would die as we butchered the roots.
Surprisingly, it didn't even lose a leaf and thrived.

2.) One is almost in full sun in the summer but has a fence five feet
back that, perhaps, offers some wind protection. (In the spring, it has
shade until about 7 am.)

Despite transplanting one, both trees have grown equally and
beautifully. I also don't notice a difference (between the two) in their
coloring throughout the year. Neither have much, if any, noticeable
leaf scorch.

The below photos are of the full sun tree over the years. It is
green when it first leafs out each spring and then turns to red. The
leaves hidden underneath tend to stay green. The photos aren't exactly
the same month each year, but they are the best I could find:

Generally speaking, Japanese maples can tolerate more sun if they have adequate water. They come from southeast Asia with summer monsoons.

Our summers in the coastal Pacific NW are relatively dry and if a Japanese maple is in an exposed, dry location, it will have a tendency to burn.

The pictures I see above have green, irrigated lawns so I assume the maples are getting watered also. The one in the Zone 7 desert has a drip line.

I think this just confirms what everyone else is saying. Full sun is the way to go!

"Full sun is the way to go!"

That may be the consensus here for whatever reason but full sun is NOT the way to go and virtually every single Japanese maple specialty nursery and JM authority will clearly indicate that afternoon shade or partial shade is a preferred location for any JM variety. Here are just a few excerpts from the websites or text articles of some of the most well recognized growers of JM's.......

• Provide morning sun and afternoon shade - Mendocino Maples
• Morning sun and afternoon shade are ideal for Japanese Maple trees. Filtered sunlight is best. - Southern Living
• Japanese maples will grow best in a sheltered position. Red and purple leaved cultivars need some sun to develop fully their dark hues. Variegated Japanese maples need partial shade to prevent the afternoon sun from scorching the foliage. Green-leaved forms tolerate full sun, but are best in dappled shade as very bright conditions can sometimes cause scorch. - Royal Horticultural Society
• I will make this straight-forward statement here, that you will also see on many Japanese maple related sites. The best possible setting for any Japanese maple is: MORNING SUN AND AFTERNOON SHADE or ALL DAY LIGHTLY FILTERED SUN. Even plants that do okay in full sun or a lot of shade will benefit from this placement no matter where you live (the only exception are a very few extremely sun sensitive cultivars that should be in deep shade). They will generally have less leaf burn and better color throughout the growing season in this preferred placement. - Davidsan's Maples
• The Japanese refer to the maples as the ‘little girls’ and the pines as the ’fathers’. In their native habitat the pines provide protection from the intense sun and wind. Though most of the trees will do well in full sun in a mild climate where temperatures are seldom above 90 degrees Fahrenheit, the heavily variegated trees will typically burn even in milder climates if exposed to afternoon sun. All of the trees will grow well in partial shade or the dappled light in the under story of a large tree. - Essence of the Tree
• Even though 'Glowing Embers', 'Trompenburg', 'Emperor I', and many of our other cultivars do well in full sun, it is recommended that you plant your maple in a place that does not receive direct sunlight after 12 noon, especially if your summers have temperatures reaching above 100 degrees more than five days each year. - Pacific Coast Maples
• Ideally, provide dappled shade; if too much the plants grow slowly and the purple types become more green; too little and they may literally cook in the summer sun. - Michael Dirr
• Protection from late afternoon and evening sun will reduce leaf scorch, sun scald and reduce the amount of watering necessary to keep the soil cool and moist. Also plants under stress are more likely to develop diseases and insect damage. Having a property with large existing shade trees to plant your Japanese maple under makes a perfect environment. Such filtered or dappled shade is ideal for Japanese maples. - Japanese Maples online

Of course you can plant your tree wherever you like but making the assumption that full sun is the best or preferred siting is far from accurate and could lead to some unfortunate consequences depending on where you are located. That's one of the problems with these online forums......you can get a lot of anecdotal advice from hobby gardeners that really may have little to no practical application.

I'll add that out of the 8 Japanese Maples I have in the ground. the ones in full sun seem to do the best. I guess YMMV.

My Crimson queen grows best in full sun and has the best red color. On the other hand my Japanese Maple Ever Red is in partial sun and still burns badly by July.