Just curious - why do you care which viburnums do well if they don't get enough sun to bloom?

I grow viburnum nudum, viburnum acerifolium and viburnum dentatum in shade. I'm always thinking to remove some small trees and give these guys more sun; they don't bloom but they grow fine.

From the perspective of interesting leaf shapes, I would pick v. nudum (glossy leaves) and v. acerifolium (maple shaped leaves) and they both have interesting fall color.

Other shade tolerant plants: native azaleas, native vacciniums (blueberry relatives) and Florida anise (illicium floridanum).

Just how dense is your canopy and have you thought of limbing up the trees to get more light down to the forest floor?

O.K. Part of my garden is "full shade", but there are so
many varying degrees of even "full Shade". . .some plants
I have had success with in "no sun" (but different levels
of full shade) include:

Abelia grandiflora (some bloom)
Symporicarpus albus laevigatus (very small pink flowers
and white berries)
Viburnum acerfolium
Dierevilla sessilifolia (great plant - some bloom)
Berberis thunbergii
Aronia arbutifolia (some bloom and red berries)

Carl

Kerria japonica will do very well, including blooming nicely, in even dense shade. Plus, the bright green stems make for nice winter interest.

- Steve

Some suggestions for shade..

Acuba japonica (vigorous grower)
Rhododendron (especially for lighter shade)
ferns

Fothergilla gardenii will grow in shade; so also will Clethra alnifolia (as long as the spot is at least dependably moist - don't count on Clethra in dry shade). They won't grow vigorously in heavy shade, but they'll grow. Witch hazel might be worth checking into as well.

I agree with Kerria japonica...I like the single-flowered one the most. IMO, it looks like a single-rose. It has just finished its abundant spring bloom flush but will throw intermitant flowers all summer. The bright green stems look stunning in winter against the snow.

Kerria japonica will grow & BLOOM even in dense shade & is quite resistant to dry conditions once established, grows to about 5', can be pruned hard to rejuvenate, and requires virtually no care unless you want to fuss with it. It's only drawback is that if given sufficient moisture it will sucker & form a thicket over time in the same way as clethra.

If you have some dappled sun/shade, then daphne is a beatiful shrub. Its white flowers (with a pinkish blush) brighten up a shade area & have the added benefit of wonderful fragrance. Mine are in bloom now & will throw smaller flushes of bloom about every 5-6 weeks all season. They perform best in soil that is organic & slightly moist...don't believe they'd do well in very dry soil.

Tricia

Acer palmatum
Acer circinatum
Symphoricarpus albus
Enkianthus
Daphne odora
Hydrangea
Tsuga canadensis - Wooly Agelid may be a problem in your area - I do not know.
Camelia - try 'Camelia Forest Nursery' for cold hybrids.
Fuchsia
Mahonia

Dax

shrubby variegated dogwoods, e.g. 'Ivory Halo', 'Cream Cracker', etc.

Also Caryopteris (sub-shrub) 'Snow Fairy' is fine in shade for the foliage. It won't bloom, but not a big loss.

Fallopia Japonica variegated can brighten up a shady area, but you've gotta watch out for runners. I had mine in a lot of shade and it did nothing for 3 years. I moved it to a spot with just bit more sun and it really took off. I am very afraid... I might move it back to the more shady spot. And in your zone, its even riskier.

Annabelle Hydrangea or even Paniculata, e.g. 'Limelight' will grow in shade. The blooms are bright and last a long time and even provide winter interest.

Camelia

If you opt for Camellia be choosy about your source. There's a nasty new disease in parts of the West Coast that grows especially well on Camellia, but also on jillions of other plants (especially Rhododendrons and Azaleas) that would not be something you would want to accidentally introduce into your garden. The affected West Coast nurseries are already well aware of the problem and are taking appropriate steps to control it, but I still thought it best to make you aware of the matter. This disease (often known as "Sudden Oak Death") is most prevalent in California, but also found in small parts of Oregon and also Washington.

Oh, and by the way, this disease is also found in parts of continental Europe. It absolutely does NOT require a Mediterranean or Maritime climate to survive. It could certainly survive just about anywhere else in the USA if there was enough moisture in the immediate environment to keep it going.

Thank you for all the great suggestions I appreciate it.To answer your question esh-Ga I like many of the Vibunums for their leaves and shape, most bloom so briefly that to use them just for their blooms would be a waste of precious space. But when they do bloom they are so very lovely.