Impatiens do really well in shade but I see you don't like them. They can be really lovely and colorful. Try some nasturtiums if it doesn't get to hot. Begonias like a shade. My geraniums do pretty well in shade w/ morning sun.

Coleus, torina, double begonias, browallia, caladium, to name a few.

* Browallia
* New Guinea impatiens
* Wax begonias
* Tuberous begonias
* Caladiums (for colorful foliage)
* Elephant ears (for large, tropical foliage)

I have to third on the impatiens. I have used them for my containers for years and love them. I plant 3 of them in my 18" container and they overfill it easily while hanging over the sides. I planted with ivy in the front this year and you can add a spike plant in the middle for some added height. There is different colors to choose from and I like the coral colored ones that would go with your color scheme. When they get leggy cut them back and they will be very bushy for you but mine only have to do this about twice a year. Sorry, I know you weren't partial to them but thought maybe you may be willing to give them another try. They are also great sources for hummingbirds and mine would come and sip from mine 2 feet from me where I have my bench.

Another here who loves impatients....the clue to making them look good is to have a great abundance of them....not a few....and I add stuff like heliochrism petiolare, browillia and some tahitian bridal veil....doesn't bloom well in the shade but cascades and looks great with it's delicate foliage.
Linda C

Fuchsias might be an option. They are great trailers and definitely fit the color schemes you're looking for.
Also, I have found that my impatiens do the best when they have LOTS of compost/organic fertilizer. A friend explained to me that they are native tropical plants that grow in the sahdy undergrowth areas where they live on the decaying matter that is constantly breaking down/accumulating around them. Boy, that made sense - the one year i used my own homemade compost and lots of it in my impatiens bed, I ended up with a massive covering of flowers that grew nearly 18" high. Both my neighbors and myself were astounded. I have never repeated those conditions and I have never gotten anything more than a low growing mound of impatients again either. (Why I haven't given them more compost love, I don't know). Anyway, just a thought. :-)

IME allysum needs a fair bit of sun to do well.

You might try polka dot plants [Hypoestes phyllostachya]. It does quite well for me in shady spots.

Caladiums are terrific in shade. I can picture them in each of your bench-boxes, and edged with a fast-growing silvery lamium cascading over the sides to the ground. If you do use caladiums, put in twice as many bulbs as suggested---I did that last summer in containers and the display was downright luxurious. And none of the plants seemed to suffer for sitting cheek-by-jowl.........Good luck!

The maple off the patio may be problematic because maples tend to be shallow rooted and very thristy. Haven't found very many annuals that do well under those conditions. That aside I'll tell you that I'm not a big fan of mass planting of impatiens either. Some of my favorites for shade are:
Coleus
Rex Begonias
Dragon wing Begonias
Browalia
Balsam
Lobelia
Torenia
and Snaps and Nicotiana (which can both take quite a bit of shade in my experience)

After reading this in more detail....I have more comments...
I still love impatiens....but they do need a certain amount of sunlight. My deck is so shady that even impatiens won't bloom....not will begonias.
I grow green plants ivies, wantering Jew...Tahitian bridal veil etc. I* have several pots of impatiens and begoina that I rotate in and out of the sunnier spot....and that gives me blooming plants on my deck.
If I had that bench round a tree and the planters in the corners....I would fill them chock full of impatiens on the 2 sides with the most sun, and have a bit of bacopa trailing down...and maybe some heliochrysm in that lovely lime green. For the less bright spots I would fill the planter with more heliochrysm....and maybe some of that curry plant ( tall, gray soft pointy leaves) and get some red leaved coleus un there.
As for the oval bed that had the rock on top....I would think of perennials....hosta, astilbe, thalactrim, pulmoneria, browalia, brunera....and impatiens for a bit of color....
Linda C

No to the hydrangea because the maple will pull off all the available water and especially so in an enclosed space. I was just looking at the Fine Gardening site and they have an issue with container gardening that looks wonderful. Maybe you could use some containers?

Here is a link that might be useful: Fine Gardening Magazine

Snapdragons might do okay for you since you are in a cooler zone. They die around here when it gets hot, but in the shade where you are I bet they'd do well.

I just picked up some torenia today that would be right up your alley! I too love purples, and the type I got is dark purple with accents of lavender and yellow -- it looks like a mutation between a Johnny Jump-Up and a Snapdragon!

Check these out:

http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/annuals/torenia_fournieri.html
http://www.gardenerspath.com/plantguide/torenia.html
http://community.webshots.com/photo/60424801/60424801uLtNUX
http://davesgarden.com/pf/showimage/17955/
http://davesgarden.com/pf/showimage/40497/

Lindac - have you considered having some of the trees around your deck professionally thinned? A good tree person can thin the branches and maintain the natural shape of the tree and let in 20-30% more light. By this I mean preserve the tree just thin out the branches a little. Just an idea to consider if it is too shady...

I've always found that lamium does wonderful under trees, so there is another option for you too :)

I am trying white nancy lamium interplanted with hostas in my shade spots. It is very pretty, and the white nancy just mingles among the hostas in a very friendly manner! I also have a tiny plant, not a clue what it is, but some kind of wandering jew type that has tiny double white blooms..it looks lovely in and around hostas. In pots of dragon wing begonias it holds its tiny white double blooms above the foliage and blooms and looks for all the world like babys breath. I would love a name for it, and it does come back after winter..does well inside and out.

Check out the perennial Corydalis lutea, small yellow flowers and lovely ferny foliage.