I grow it in medium shade, mid-morning to very early afternoon sun, maybe 3-4 hours of sun off and on. I bought it 2 years ago and it is growing and appears healthy. I don't think it would do well in heavy shade.

Funny - I was just trying to find these locally. Not easy but finally scored! I planted two of them two years ago (I think, but maybe it was three) under a Kwazan cherry tree and they are performing beautifully. They get shade during the strongest afternoon sun but do sun get late afternoon through the end of the day and have not burned at all. The shade they do get is bright shade. The variegation is crisp in this location - not really sure how a shadier/less bright shade location would affect the variegation. They aren't putting on growth super-fast but they have gotten somewhat larger.

The three I just bought I'm going to plant in an area that gets less sun - maybe a couple hours a day at most - but is not a deep shade, so I'll see how they do there.

BTW: IIRC, the guy at the nursery said not to put in an afternoon sun location - will burn.

I would imagine that they do well in a lot of shade. The native plant from which it was selected, diervilla lonicera, grows and blooms well in the heavy shade of a hardwood maple forest. I have always been impressed to find them flowering away in the deep shade of the forest where few other plants or shrubs could grow.

Cool Splash is Diervilla sessilifolia, southern bush honeysuckle. Unvariegated D. lonicera is what grows in my woodlands and I'm not sure how similar they like their growing situations. I see it pretty much along shaded woods edges where it gets 2 or 3 hours of sun, either morning or really late afternoon, but not where it will get hot sun or where it gets no sun.

I have been growing the plant since I first developed it in 2005 while at Cornell. It will do fine in shade but from my experience the variegation might not be as spectacular in very deep shade. It will also have a looser habit and take longer to grow into a nice specimen. I grow plants here in California in full sun. As long as it gets regular water it's fine here right out in the open. In New York plants did just as well in part shade and full sun. I would not plant it in deep shade if I had a choice but if you do let me know how it does for you.

Variegated Plant Foliage, a nursery in Connecticut where I got my first
specimen a couple of years ago, was selling this new introduction as a
SHADE plant - mine has done all right in medium shade, but when I
visited VFN this Spring, I discovered they have changed their recommendation
to partial shade. So, my newest acquisition is sited in morning sun and
afternoon shade. . .by the end of the season I should be able give you a
definitive answer. From my experience with other variegated plants,
I suspect that half-sun will bring out the best variegation, while too much
sun (especially afternoon sun) will result in scorching.

Carl

well p podaris, you are one TALENTED fellow! I read the backstory on this and it was fascinating. What you can accomplish sometimes against your will, i guess!
thnx so much. i will be trying it under a J maple Katsura w/ eastern exposure and will report back. Congrats on this big time success of yours!
best,
mindy
www.cottonarboretum.com/

Now that the growing season is done can you update us re the success of this plant in 'Medium to Heavy Shade'?

It def did NOT work under that J maple. We moved it after it was clear that it was major unhappy and hopefully it will recover eventually.sigh. a laurel had also been v unhappy in that spot, so i guess it's just gotta be hostas there.

Mindy - I don't know if you've tried any of the following under the Japanese maple, but here are some things that have done all right for me with low light and relative dryness that maples can create (just to provide something in addition to hostas.)

Epimedium
Heuchera, Tiarella and Heucherella, particularly the gold ones that scorch in too much sun.
Iris crestata
European ginger
Perhaps variegated Polygonatum/Solomon's seal
Perhaps the slowly spreading form of Astilbe chinensis
Perhaps Veronica 'Georgia Blue' which grows for me in a lot of shade but not a lot of root competition

In late June/early July I planted a grouping of five on the other side of a Japanese maple - not directly underneath it - and under the shade canopy of a large, established sugar maple (about 10' from the trunk), which is the area I mentioned above. The soil is not great and on the drier side, but I do have sprinklers which hit the bed, so they did get supplemental water from the sprinklers, and I did hand-water occasionally just to be sure. I was going to go with three shrubs, but a grouping of five looked better.

Most of them seem to have done fairly well this season except one. I think the problem with that one is I may not have planted it deeply enough because of the way the sprinkler lines run (and I want it in JUST the right spot goshdarnit!), and it seemed to be slowly petering out over the season, losing leaves little by little.

Really, though, it's too early to tell how they will perform in that location, it's only the first season.

Deep shade is not good. You wont see the variegation develop to it's full potential. Here in California I grow it out in the full sun. On the east coast where I first developed the plant I tested it from North Florida to Upstate New York in full sun. The variegation might not develop well in cool spring but it will surprise you when the heat starts. It likes the heat and really shows off it's colors in warm bright places. It becomes too leggy in shade. It is hard to forget the dogma (no offense to garden writer) that Diervilla is just for the shade. It may tolerate it but in order for it to look it's absolute best. Take it from someone who has literally grown thousands of plants. SUN SUN SUN.......