“An Iconic California Tree”
An iconic tree of coastal California, redwoods are native to a thin coastal band from Oregon south through the Big Sur region of California, but are planted widely beyond that range also. Coast redwoods are the tallest trees in North America. The lumber is highly valued for its beauty, is light weight and resistant to decay. Its lack of resin makes it resistant to fire, so it is used extensively as building material. During the great fire in San Francisco in 1906, the use of redwood lumber in framing rendered some buildings fire resistant. In the past, railroad ties and trestles were made of redwood. While there remain pockets of old-growth trees, ancient coast redwoods are rarely found near urban areas.
Culture
- Performs best in deep organic soil with continuous summer moisture supplied by coastal fog; despite being native to a Mediterranean climate, this is a high-water-use species
- Canopy appearance is normally thinner in more southern and inland areas
- Very sensitive to salt spray, as well as to salt or boron in irrigation water – results in marginal scorching
Concerns
- Often topped and so may need redevelopment of leader
- Sensitive to soil moisture and heat stress
- Stressed trees often infested with spider mites and/or redwood scale; may show branch death due to Botryosphaeria canker
Bartlett Management Practices
- Prune to reduce the end-weight of extended branches
- Avoid raising the canopy; the root zone should be shaded and cool
- Creating ‘windows’ in the canopy to reduce wind resistance not recommended
- Provide 4″ to 6″ layer of organic mulch
- Ideal candidate for Root Invigoration process
- Irrigation and phosphite soil treatments during dry periods
- Mite treatments may be warranted for management of heavy infestations
