Q&A with Michael Fleming: Garden Management Insights

Q: This garden is full of unusual plants. Which should be grown more in home gardens?
A: Red horsechestnuts (Aesculus x carnea 'Briotii') thrive in Northwest gardens, as do all Ceanothus—from 10-ft-wide 'Concha' to groundcovers gloriosus, griseus horizontalis, prostratus. Coast silktassel (Garrya elliptica) is an underused native that shines in winter. Among roses, 'Bonica' is free-flowering with wonderful red-orange hips in fall/winter.

Q: When replacing choice trees/shrubs, do you buy specimen-size or smaller?
A: I buy small: 1-gallon mostly, never larger than 5-gallon. Smaller plants grow faster and adapt better.

Q: Where do you shop for unusual plants?
A: Forestfarm in Oregon (541/846-7269). We also keep replacements in an on-site greenhouse/nursery; extra palm trees sometimes sold at visitor center (windmill palms this month).

Q: The garden has plants from 104 families, 299 genera, 573 species. How do you track it all?
A: For containers, bury one tag in pot bottom, attach identical tag to plant. For garden plants, bury tag on north side of rootball, second tag on branch. Number each bed, cross-reference in database. Computer replaced file cards—lost tags reprinted easily.

Q: Do you use chemical sprays for pests?
A: A little. Started IPM in 1989; reduced spraying increased bird populations, butterflies returned. Now spray only for spot weed control and major problems (e.g., tent caterpillars). Spray in still early morning when insects aren't active. For home gardeners, evening is best (bees inactive).

Q: How do you deal with weeds?
A: Mulch every bed with 2″ wood chips (free from tree trimmers). Spot-spray Roundup—biodegradable, breaks down rapidly on organic matter.

Q: Do you fertilize trees and shrubs?
A: Yes. In January, after renewing wood chips, feed. One 7-lb coffee can of 5-10-10 covers ~200 sq ft.

Q: What's your watering program?
A: Used to water weekly for an hour, but clay soil caused runoff, roots stayed shallow. After losing a Nothofagus dombeyi in a storm, switched to less water more often. Eliminated runoff, kept soil moist deeper. Haven't lost a tree since.