The redwoods native to California have a mountain species called giant sequoia and a coastal species called coast redwood. Giant sequoias are the most massive single-stemmed trees on Earth, while coast redwoods are the tallest. Each species is best suited to different conditions because of their specific adaptations. Below is a table of their most important attributes that is useful for understanding if they will do well for your needs. This table is a supplement to the FAQ below for growing redwoods in the Pacific Northwest (PNW).
Planting, establishment, and growth
In general, the western slope of the cascades, the Puget trough, and coast range will work for either species (with some limitations below), while the eastern slope of the cascades and intercontinental mountains are better for giant sequoia. The dry pine forests, shrub steppe, and deserts of eastern Washington are poor places for either species without supplemental water.
Coast redwood: Is harmed by aerosolized ocean water, so is best planted away from first contact with ocean winds coming from areas with strong wave action. Outside of the ocean spray zone, proximity to the ocean or other large water bodies will assist coast redwoods by reducing freezing temperatures and increasing summer moisture. It is sensitive to prolonged hard freezes (below 10 to 15 °F), so should not be planted at high elevation (1500 to 2000 ft) or areas with cold air pooling. Coast redwood does best in deep moist soils and can tolerate hot and dry conditions if it has access to water. This species can meet 30% of its water needs from fog, so if your climate is dry in the summer but has frequent morning fog, coast redwood is a great species for you. Coast redwood can grow well in the shade, so it can be planted alongside previously established trees or in the open.
Giant sequoia: Can grow poorly in foggy coastal climates, although it will still live. This species tolerates snow and hard freezes as well as dry hot summers. In its native range, it is often restricted to well-watered areas, so should be planted in soils with summer moisture (avoid dry ridges) or be provided with consistent water until it is established. The soils in its native range are often derived from decomposed granite which are well-drained soil types. Giant sequoia does not tolerate shade well, so make sure to plant it in full sun and control competing shrubby vegetation until it is free to grow.
Both species of redwoods produce potent compounds that are deposited in their wood and foliage. This makes them unpalatable to most insects and even deer and elk. While they are browse-resistant, this depends on the local ungulate (deer and elk) population pressure. Giant sequoia foliage is spiky, which deters browsing. Male ungulates will rub on trees during the fall, maiming them.
Bears can be problematic for both species in their native range. In areas of California where many young trees have regrown following logging, bears climb them and strip the bark to reach the underlying soft tissue. This appears to be a learned behavior, so the presence of bears does not mean they will be a problem. This is not a problem reported by people growing redwoods in the PNW. Bears prefer to strip trees from 6 to 10 inches DBH but will climb larger trees and strip the tops down to this diameter.
Redwoods will do well nearly anywhere west of the cascades in the PNW, but you will need to be mindful of their specific attributes. Both species do well with lots of water and sun. Only coast redwood does well in the shade. Giant sequoia will do better than coast redwood in well drained pumice soils and at higher elevations that experience hard freezes. Although elevation in their current range is not directly comparable to elevation in the PNW (temperatures decrease with latitude and elevation), a good rule of thumb is that above 1500’ elevation in Washington and above 2000 ft elevation in Oregon is going to favor giant sequoia.
If you are interested in growing lumber, then coast redwood planted in areas that are protected from hard freezes (<10 to 15 °F) is best. Planting this species close to large water bodies or as an understory species in a mixed planting will protect it from top damage from hard freezes. If you are interested in complex crown architecture or carbon capture, then you can plant coast redwood in hard-freeze-prone areas, recognizing that you will likely end up with a tree with multiple tops.
Giant sequoia naturally grows with trees like dry-type Douglas-fir, ponderosa pine, Jeffrey pine, sugar pine, and true firs. It will do quite well in many of the same locations as coast redwood, but will do better than coast redwood in drier climates as one moves east of the cascades and in more well-draining soil types.
Both species can benefit from early watering until they are established. They should not need any fertilizer. See the question below about planting redwoods near structures.
Redwoods can be planted with many other species, but be aware of how they will affect the local soil and light conditions. Conifer foliage tends to acidify soils, so good companions include plants that tolerate low pH such as rhododendron and huckleberry. Coast redwood creates heavy shade, so can kill sun-loving plants. Giant sequoia should not be planted under the canopy of other trees because it does not tolerate shade well.
Coast redwood understories in California commonly include maples, tanoak, bay laurel, sword fern, deer fern, sorrel, salal, rhododendrons, and huckleberries. Giant sequoia understories commonly include true firs, white alder, dogwood, beaked hazelnut, and bracken fern. This list is only partial.
The foremost concern is their large eventual size. Small properties with many structures are not good places to plant redwoods. We recommend planting redwoods no closer than 35 ft to buildings or walkways. Branches on mature trees can easily extend 18 ft from the trunk and the roots will damage foundations and sidewalks. Redwoods of both species with good access to sunlight and water can increase their girth 0.5 to 1 in per year and their height more than 2 ft per year for the first 35-50 years. Try to imagine how a tree 2 to 3 ft diameter, 70 ft in height, and with a 30 ft crown spread will fit into your property in as little as 35 years, or even how a 10 year old tree that is 20 to 40 ft tall will fit.
Coast redwood in particular, produces very deep shade with dense flattened leaves. If you value winter sun, do not plant redwoods to the south of windows. Each fall, older clustered units of stems and leaves are shed and replaced the next spring. These will clog gutters and form mats of debris on flatter roofs.
In areas with hard freezes, coast redwoods may develop multiple tops. Such “candelabra” trees can develop weak fusions between multiple trunks where bark gets encapsulated between the trunks. These areas can be prone to failure and damage to vehicles and structures below them.
Redwoods planted now will only reach a tiny fraction of their potential size in a full human lifetime, so it can be hard to accurately imagine how they will fill a space when you are long gone. Consider what the consequences of planting such a huge tree will be for the tree and for the people that come after you. It may have to be removed, and a great expense, to minimize branch fall hazards and foundation damage, or one may not be allowed to remove it due to heritage tree rules that forbid cutting down trees larger than a given diameter. PropagationNation’s mission is to have more redwoods, and planting them in locations they will eventually have to be removed from is not in-line with that mission!
Ecology and Ethics
Whether redwoods are native to the PNW depends on what time frame one chooses to look. Since Europeans arrived in North America, the natural range of giant sequoia has never extended beyond the Sierra Nevada nor has the coast redwood range extended north of southern Oregon. However, both redwood species will likely shift north naturally in the distant future and their common ancestor has been in the PNW in the distant past.
The current range of a species is often thought of as being climatically limited, but this can be deceiving along the front edge of a shifting population. The climate patterns within the range of redwoods do not tell you where it cannot grow. If it did, we would not see redwoods more than 6 ft diameter and 100 ft tall in Seattle, WA! The current range is due as much to historical events that may have limited a range in the past that are no longer present (e.g. glaciers). The only reason some species do not have a larger range is because they are unable to disperse into new areas and establish at the same pace these areas are becoming climatically suitable habitat.
The PNW is predicted to have warmer wetter winters and hotter drier summers, more like the climate of most redwoods in their current natural range. Those on the southern boundary are limited by drought, while those on the northern boundary appear to be unlimited. Additionally, all the major tree species we associate with the PNW already occur alongside redwood in their native range. This suggests that redwoods may already be moving north at rates imperceptible on a human timeframe.
Fossil records show that both redwood species once ranged more widely and at one time also included the deciduous dawn redwood (Metasequoia) now occurring only in China. Likewise, modern coast redwood analogues likely occurred in China. We generally do not find fossils resembling coast redwood north of Washington or Montana, while we do for those of giant sequoia and dawn redwood. Fossils of their common ancestor have been found in British Columbia, northeastern Washington and many locations throughout Oregon.
There is some confusion about the terms non-native and invasive. Non-native plants are simply those that occur outside of their natural range. Invasive plants are those that can escape cultivation and take over areas to the extent that they reduce plant diversity. Himalayan blackberry and scotch broom are good examples of the latter, while Japanese maple is an example of the former.
Redwoods are unlikely to become invasive for two reasons:
- Redwoods naturally occur with nearly all PNW forest tree species within their natural range and do not extricate these species where they co-occur. Coast redwoods only reach nearly 100% of the tree species in small pockets of narrow valleys with deep saturated soils (e.g. Montgomery Woods State Natural Reserve in CA) and giant sequoias never do.
- Redwood reproductive strategy is not conducive to rapid and long distance reproduction. Coast redwood seeds have low viability and only produce consistent cone crops in the drier parts of their range. The seeds of both species are small, so sprouting seedlings are unable to outcompete ground vegetation unless mineral soil is exposed after a fire or if they land on plant-free decaying logs.
Although redwoods will not spread uncontrollably, they will be a more-or-less permanent tree once they establish themselves. Coast redwood resprouts from its roots if it dies and neither species are likely to die from disease, wind, or fire.
Planting redwoods will generally increase the resilience of PNW forests by providing a forest tree that is long-lived, is impervious to many diseases, and responds well to fire. Despite their height and shallow root systems, they are also remarkably wind resistant. This means that when a forest is exposed to disease outbreaks, fire, and wind, redwoods provide two additional species to the forest community uniquely suited to resist these disturbances or re-establish after them.
Both redwoods can live more than 2000 years. This gives them time to develop uniquely complex structures within the tree that provide habitat in the canopy, including soils and dead wood that supports plants and animals well above the ground. The only species in the PNW that compares to redwood in this way is western red cedar, which is much smaller and slower growing.
Both redwoods can be important on and below the ground as well. Large logs serve critical functions in the forest and in streams including but not limited to: increasing water storage in the summer, providing nurse logs for new tree regeneration, diverting deer and elk browsing, and creating salmon habitat. Redwoods produce the largest and most decay resistant logs of any species. They also form fungal soil relationships that are distinct from those of the PNW’s most dominant species (Douglas-fir and western hemlock), which will enrich the soil biota’s diversity.
Some possible negative effects are that when coast redwood dominates, such forests tend to have lower biodiversity. This is likely because coast redwood is unpalatable to almost all insects and casts very deep shade making it hard for many understory species to grow. The density of the largest trees in a forest play a dominant role in how a forest ecosystem can function, so redwoods should be included in the forest with some amount of prudence.
To maximize forest ecosystem functions, redwoods should be incorporated as a component along with tree species already present in the PNW such as Douglas-fir, western hemlock, Sitka spruce, and western red cedar. There are few, if any, major tree species in the PNW that redwoods do not already grow next to in their native range, showing that they can coexist.
Coast redwood has the unique ability among western conifers of being able to resprout after fire or logging. The roots then fuel the growth of resprouts beyond that of seedlings. This makes coast redwood a persistent species that can provide nearly uninterrupted hillslope stability and tree cover. Because they tolerate shade and those in the shade can be supported by the roots of those in the sun, redwoods can exist in the forest as large and small trees at any given time in dense or more open-canopied forests.
Giant sequoia has green long-lived cones that accumulate over decades and are held high above most other trees. Therefore, this species is less dependent on the quality of the cone crop in any given year if there also happens to be a high-severity fire. If there is a severe fire, a literal rain of accumulated seeds showers to the forest floor and re-established on exposed fire-scorched soil.
Benefits: Both redwoods will grow in very wet soils where Douglas-fir will not. They also produce very large and durable dead wood that can increase the complexity of stream channels and slow water flow. The roots of coast redwood are more or less immortal, so will provide long term bank stability even if logged. Coast redwood also casts deep shade, so it can be used to strategically shade vulnerable portions of streams (e.g. sunny bedrock channel with little cold ground water). In foggy coastal areas, redwoods can contribute water to the ecosystem because its large size and dense foliage catches fog that then drips to the understory.
Concerns: Redwoods consume a lot of water, so may not be the best choice close to small headwater streams where summer low flows are important (this goes for Douglas-fir as well). They, like all conifers, produce acidic foliage that may not be the most nutritious source of leaf litter to stream ecosystems. They also produce dense shade, which can reduce streamside herbaceous and shrub cover.
There are few natural diseases of redwoods. Both are resistant to common root pathogens such as laminated root rot, phytophthora, armillaria, and others. There are some redwood specialist wood decay fungi that are slow acting, so are only a problem in very old trees. These are heart rots (they eat the red heartwood of trees) in the genus Poria.
Young coast redwoods in plantations can be harmed by a twig/branch canker (Coryneum species), and there are a few insects that cause only minor damage. Giant sequoia can be minimally affected by annosus and Armillaria root rot, and are only killed directly by these pathogens when young. It appears to be more susceptible to disease at lower elevations in their native range.
Silviculture (the combined process of preparing a site, planting and tending trees, harvesting trees, and selling the logs)
Although both species are resistant to browsing, no trees are immune if ungulate (deer and elk) pressure is intense. Many folks have planted redwoods without any protection and have had no issues. Some folks have had small numbers of trees killed by deer or elk rubbing on them and there is at least one case of bears stripping some giant sequoias.
If one chooses, there are plenty of solutions for protecting larger plantings. These include solid translucent or mesh tree tubes that a tree can grow out of with no further maintenance.
Both redwood species are resistant to these and other common diseases in the PNW. Coast redwood is as resistant to laminated root rot as western redcedar and slightly more so than giant sequoia. Both are also resistant to phytophthora root disease.
Young coast redwoods in plantations can be harmed by a twig/branch canker (Coryneum species), and there are a few insects that cause only minor damage. Giant sequoia can be affected by annosus and Armillaria root rot, and are only killed directly by these pathogens when young. It appears to be more susceptible to disease at lower elevations.
Your objectives will determine your planting density. If you want large spreading tree crowns, plant either species more than 20 ft apart or even further if planting a grove where interior trees will be shaded by neighbors. As with any tree, closer spacing concentrates growth into height rather than girth or crown spread. Larger spacing creates shorter trees with wider crowns, lower branches, and more tapered (less columnar) trunks.
Coast redwoods grow well at operational spacings commonly used in the timber industry (10’x10’ to 12’x12’), however, one should plan for lower mortality and poorer branch self-pruning than for Douglas-fir. Denser planting can force self-pruning, but may also require more pre-commercial thinning because the trees are less likely to die from competition given their tolerance for shade.
Giant sequoia lumber is hard, if not impossible to market. Old trees have a reputation of producing brittle wood, although there is some evidence younger trees are usable. Lumber may be susceptible to carpenter ants. This species will likely be used in a tree farm setting as a carbon sequestration species. Given its eventual large size and shade intolerance, it probably should not be planted closer than a 20’x20’ spacing (~100 per acre). Larger spacing will also allow later planting of understory shade-tolerant trees that can be harvested.
If you would like more wildlife habitat and biodiversity in your forest or want to plant alongside other species, you should reduce the overall tree density, but vary it locally. Plant 100 or fewer redwoods per acre with no more than 15% dispersed as individuals. The rest should be in clumps of varying size to allow for future canopy gaps and dense clusters of interacting tree crowns that will create within-crown habitat diversity.