Mike Waller wrote:

>Dennis,
> I've noticed a couple of comments disparaging "Rhoddies". I assume that
>those comments were aimed at the 600 species of Asian Rhododendron, and
>assorted gaudy hybrids, not our own Pacific Rhododendron, R. macrophyllum,
>or the misleadingly named White Rhododendron, R. albiflorum or cascades azalea.

Wild rhododendron species, wherever they grow, are among my favorite green
critters, but I'd probably disparage "gaudy hybrids" in any plant group.
However, I have rationale beyond my prejudices.

Although I assume the native rhododendron has its own herbivorous insects,
I'll bet they are a lot less common than those on various deciduous
species. One of the strategies of being an evergreen is to keep your
long-lasting leaves in good condition, and one of the ways to do that is to
devote a lot of metabolic energy into filling them with antiherbivore
compounds. The deciduous species put more energy into putting out that big
bunch of leaves every spring, and they aren't made to last a long time, so
they aren't so full of chemicals. A recent study in the Condor showed that
breeding birds in southern Alaska were considerably more common in
deciduous than in coniferous (evergreen) stands.

That's why it's better to go deciduous when planting for wildlife, except
for the obvious caveat that evergreens provide good cover in winter. Thus
I guess a mixture of plantings should be the best strategy, but I'd go
heavy on the deciduous, with strategically planted evergreens for cover.

Dennis Paulson, Director phone 206-756-3798
Slater Museum of Natural History fax 206-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416