JARS v47n1 - RSF Displays New Alpine Garden

RSF Displays New Alpine Garden
A Convention Highlight
Steve Hootman
Federal Way, Washington

Attendants of the 1993 ARS Annual Convention to be held in Tacoma, Wash., are invited to study and enjoy the fascinating diversity of our high alpine flora. Don't bother with altitude sickness medicine, however, for these plants, usually found growing in the rarefied atmosphere above timberline, may be observed in the Alpine Garden of the Rhododendron Species Foundation in Federal Way, Wash.

Designed as a growing and display area for alpine rhododendrons and companion plants, the Alpine Garden was installed in 1983. Along with the gravel and sand added to improve drainage, over 200 tons of large granite boulders from the Cascade Mountains were incorporated into the site to simulate a natural mountain landscape. In this area the visitor can enjoy alpine plants from high mountain ranges all over the world, including Asia, Europe, North and South America, and even New Zealand.

A few of the more interesting alpine rhododendrons to be seen include: Rhododendron camtschaticum , R. nivale ssp. nivale and ssp. boreale , R. lapponicum , the distinct R. setosum , many forms of R. campylogynum , R. russatum , R. fastigiatum , and the rare R. collettianum . Prominent alpine companion plants include: dwarf conifers of many genera, Cassiopespp. , Phyllodoce spp., Saxifraga spp., Androsace spp., Campanulaspp. , Daphnespp. , Centiana spp., Penstemonspp. , Soldanellaalpina , Primula spp., Dianthus spp., and several outstanding specimens of the rare Kalmiopsis leachiana , endemic to the Siskyou Mountains of Oregon.

Recently, in an effort to maintain the quality and diversity of species grown, we have initiated major renovations of large areas in the alpine garden. As a result of our efforts this past summer we have completed a full inventory, relabeled each species, and installed three limestone screes.

The screes are ideal areas for cultivating demanding plants such as porophyllum saxifrages, androsaces, Raoulia spp., Campanula raineri , and Eunomia oppositifolia . Situated on sloping ground at the lower end of the garden and exposed to the bright but cool morning sun, the screes mimic the natural jumbled rock scree formations seen on high mountain slopes. Construction of the screes began with the excavation of the native soil to a depth of two feet. This was backfilled with a mixture of one part sand: one part organic matter: two parts gravel: and two parts limestone chips. Another three to four inches of limestone chips were used as a mulch to keep the soil cool and the crowns of the plants dry. This extremely well-drained media is a must if you wish to cultivate these plants outdoors in the mild wet winters of the Pacific Northwest.

One scree is devoted entirely to species native to the European Alps. Situated between plantings of Rhododendron ferrugineum and R. hirsutum , companion species such as Leontopodium alpinum (edelweiss) and Gentiana acaulis (stemless gentian) grow and flower. While R. hirsutum , a lime lover, is growing directly in the scree, R. ferrugineum , a lime hater, is restricted to the typical organically enriched, acidic soil adjacent to the scree.

We hope to see you at the Rhododendron Species Foundation this April and encourage you to spend some time in the Alpine Garden. It promises to be as exhilarating as a mountain hike but much less strenuous.

Steve Hootman, assistant gardener at the Rhododendron Species Foundation, is a 1987 graduate of the Public Horticulture Program at Purdue University and former curator of the Winkler Botanical Preserve in Alexandria, Va.