Wednesday, May 13, 2009

Knowing Northwest Natives

The stampede to native plantings is a good thing overall, but there are misconceptions about how to use native plants and what to expect from them. Some people adore all native plants simply because they are ours; others dismiss them as so much brush. Many people would never buy what they could supposedly drive into the countryside and dig up. Let's look at the facts.

A native plant is a species that has grown wild in your climatic region since before settlement. With a tremendous variety of climate and terrain, the states of Washington and Oregon have many natural zones and well over 3,000 native plants. Species from high mountains may not grow in low elevation gardens; those of the sagebrush deserts may rot if planted on the coast.

Similarly, each zone has various habitats- wetlands, dry bluffs, alluvial valleys, north and south exposures- and most plants have strong preferences. It is dangerous to assume all native plants are drought-hardy, though many are quite adaptable.

Nor are native plants all easy to grow. Many Northwest natives, even common ones, are challenging to propagate and establish. Plantings of salal (Gaultheria shallon) are usually riddled with casualties. Low Oregon grape (Mahonia nervosa) and blue elderberry (Sambucus caerulea) are notoriously difficult to propagate, as are most of the lily family. Native plants fall victim to pests and diseases just as much as most introduced plants. Deer, especially, are fondest of the plants they know.

Then there is lack of selection. While we have a large flora because of climatic diversity, in any one area the variety of native plants is low and, for many of the reasons above, some of the plants we have are impractical for landscape use. We have almost no trees suitable for streetside or patio, few showy flowering shrubs, few evergreen screen plants. Most of our conifers are too towering for smaller landscapes.

But the good of natives outweighs the bad. First, they simply belong here. Native plants should always be considered first as candidates for any landscape role. If a native plant makes sense, it should be used.

How sensible any plant choice is depends on the situation. For rough and wild areas, natives are a must. Closer to civilization, the matter is more complicated. Considerations of wildlife value and native purity may clash with the desire for showy flowers, fragrance and architectural forms that may not be offered by any native plants. Most successful plantings manage to combine native and non-native just fine. Some beautiful gardens are made of Northwest natives alone.

Next time, I'll try to make a list of the most useful Northwest native plants for gardens and commercial landscapes.

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