Root weevils are the most common pest attacking Rhododendrons in the Pacific Northwest so they can only be temporarily eliminated from any garden. If the environment is right and their food source returns, so will the root weevils.

If you want to keep your current Rhododendrons, the weevils can be controlled if you’re diligent (forever!?). However, it sounds as if you’re willing to remove them and start fresh. Some of the most susceptible (host plants) are Rhododendron and Azalea, Heather, Salal, Manzanita and Kinnikinnick, Pieris, Maples, Viburnum, most Conifers, Astilbe, Cyclamen, Helleborus, Hosta and Primrose.
(Source: Root Weevils in the Nursery and Landscape; Identification and Control, by J. DeAngelis and G. Garth, EC 1485, Oregon State University Extension Service).
http://extension.oregonstate.edu/catalog/pdf/ec/ec1485.pdf

The following website has an excellent list of resistant Rhododendron varieties: http://cru.cahe.wsu.edu/CEPublications/eb0970e/eb0970e.pdf.

Season All Season
Date 2008-01-24
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The short answer is to plant shrubs and groundcovers.

The long answer is that slope stabilization is a serious concern and deserves expert advice. Get started in your research by reading the articles on the WA Dept. of Ecology site:
Controlling Erosion Using Vegetation.

Your condo association may want to hire a consulting arborist and/or a civil engineer ("To locate technical experts such as experienced registered engineers specializing in geotechnical and/or drainage projects, use local telephone directories or call the Seattle or Kitsap branch of the American Society of Civil Engineers (ASCE) for membership references." from DOE site)

For an arborist referral try:

Plant Amnesty

Pacific Northwest International Society of Arboriculture has a list of certified arborists, as well as a set of guidelines for hiring an arborist.

The following site can help to narrow the search to your area: www.isa-arbor.com

Season All Season
Date 2006-11-14
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There are a number of conifers listed on the locally developed web pages of Great Plant Picks.

I would suggest looking at some of these, and then checking the web page of SelecTree, where you can select trees for low root damage potential.

For instance, if you are interested in planting a fir tree such as Abies grandis or Abies pinsapo, you would find out from SelecTree's full tree record that both of these have moderate root damage potential. Calocedrus, Picea orientalis, Sequoiadendron and Cryptomeria are also rated as moderate. Cephalotaxus fortunei is rated low, as are Pseudotsuga menziesii, and several Chamaecyparis species. The following conifers rated as having high root damage potential:

Picea abies NORWAY SPRUCE

Picea brewerana BREWER'S WEEPING SPRUCE

Pinus cembra SWISS STONE PINE

Pinus nigra caramanica CRIMEAN PINE

Pinus taeda LOBLOLLY PINE

Season All Season
Date 2007-01-25
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I am really not sure what their rationale might be. I agree with you that planting in the fall is preferable. Here is information which supports this:
Brooklyn Botanic Garden booklet on conifers
Excerpt:
"Across most of the country, spring (early or late, depending on how far north you are) and early fall, when temperatures are cooler and rainfall more abundant, are the best times to plant conifers. To reduce transpiration or water loss from the tree, plant on an overcast day when there is ample soil moisture."

I don't know if your tree was a bare-root specimen or container-grown. Here is what Keith Rushforth says in his book Conifers (Christopher Helm, 1987):
"Bare-rooted stock can only be planted during the dormant season. This restricts planting to the period November to April. Planting during midwinter is better avoided, because cold, dry winds during the winter can desiccate the young plants before the roots have been able to make new growth. Planting after April is only feasible if the plants have been held dormant in a cold store.
Container-grown stock can be planted out during most of the year, although the period of maximum growth from late May to early August is better avoided unless watering is no problem. A check should be kept on whether winter-planted stock needs watering; it is very easy for the compost to dry out during dry periods in the winter."

Based on the above, it seems like a good idea to plant now (fall).

Season Fall
Date 2009-10-29
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