Visit this page for frequent updates regarding Golden Gardens' Forest Health and recommended next steps that can lead to successful maintenance and restoration. We encourage discussion on these topics at our Discussion Forum! If you have a question or comment, please join our Google Group and post your feedback!
GSP has identified three target forest types to serve as a template for restoration efforts throughout Seattle. These forest types include: Conifer Deciduous Mixed Forest, Conifer Broadleaf Evergreen Mixed Forest and Riparian Forest. Based on these three target forest types, GSP has created specific thresholds for canopy cover, tree regeneration, species diversity, shrub cover and ground cover. A Restoration Site Report was developed for Golden Gardens to give Forest Stewards an easy to access status report on a specific GSP site and to help identify actions that will move their sites towards targeted goals. These target forest types are preliminary and will be adjusted as work on describing Seattle’s target forest types is completed.
Read Golden Garden's Restoration Site Report here!
The following information has been provided by Clay Antieau, Botanist and Horticulturist with Seattle Public Utilities. Contact Clay with questions at:
Clay Antieau700 5th Ave#4900 Seattle Municipal TowerPO Box 34018Seattle, WA firstname.lastname@example.org@netzero.net
critical to outcompeting invasives.
Evergreenness is an important survival and
competition strategy for plants living in the Moist Maritime Pacific Northwest
because it allows species to avoid/tolerate the natural summer dry period and perform photosynthetic work in the winter-wet period. It is also the
first-line defense mechanism in the resistance and resilience of these forested
ecosystems against invasive alien species. Note that most of our most
successful invasive alien plant species are evergreen. For a useful
discussion (and quick read) about resilience in ecology and social systems, see
“Resilience Thinking: Sustaining Ecosystems and People in a Changing World” by
Brian Walker and David Salt (available through Amazon). As a restorationist,
you need to consider how the restoration work you implement potentially
improves or enhances the resistance and resilience of your restored ecosystem in
the face of very real disturbance and uncertainty such as invasive organisms,
global climate change, increasing pollutant loadings, and so forth. You
should be able to clearly articulate how your restoration strategies at Golden
Gardens address these threats.
Recommendations: Pacific Yew, Sitka Spruce, Cedar, Hemlock, and Doug Fir (in full sun), fern, salal.
Any evergreen is a good evergreen as long as it is planted to match the site (i.e. growing conditions). Consider evergreenness at all canopy levels in the ecosystem (tree canopy, tree sub-canopies, shrub canopy, herbaceous canopy; moss./liverwort canopy….) Other native evergreen vascular plants to consider include, Mahonia aquifolium, Abies grandis, Pinus monticola, Linnaea borealis, Tellima grandiflora. Tiarella trifoliata, Tolmeia menziesii, Carex obnupta (wet), Carex deweyana, Geum macrophyllum, and the following species that are notably excellent candidates for your Golden Gardens site: Lonicera hispidula, Mahonia nervosa, western sword fern, Paxistima myrsinites, Carex hendersonii, Rubus ursinus…..
Witnessing slow growth when needed.
Because Douglas-fir is not shade-tolerant (unlike western redcedar and western hemlock), planting Douglas-fir in a shady understory ends up being a waste of your time and the nursery stock. Always match planted material to the existing growing conditions. The large existing Douglas-firs at Golden Gardens started there after some event that “cleared the way”—perhaps a logging show or fire many decades ago.
Preserve openings for conifers
Forest gaps are important places for increasing unique biological diversity in an otherwise closed canopy forest restoration. Douglas-fir is not shade tolerant, but is suitable for planting in the sunnier gaps. However, other species (such as bigleaf maple) like the gaps, too. To promote growth of specific diversity you may need to actively control growth of other native species more common through the project area. Once your desired plants reach a suitable size (“free to grow”) you can often ease up on managing the other species.
THE PLATFORM QUESTION
To build or not to build... a platform.
Platforms are not needed for blackberry (i.e. the blackberry does not re-root) based on my (and others’) experience. The point is that your energy (and the wood) in constructing the platforms can be put to better use. However, make sure that any blackberry is dug out from the places where you construct the piles. There is some real concern about English ivy re-rooting in piles without platforms, but, again, to save the Effort of building platforms, I just build a pile of blackberry first and then throw the ivy on top of that; no re-rooting. I do the same thing with cherry (English) laurel, Portuguese laurel, English holly, sycamore maple, and Norway maple. That is, for any individuals I dig out (usually less than 2 inches diameter at breast height), I lop (remove branches and cut the main stems into 4 to 8 ft lengths) and pile that material directly on the ground with the root mat usually the last to be placed on top of that pile; no re-rooting. The lopping is extra effort, but my goals there are to minimize pile size (and maximize planting area), and to get that material as close to the ground as possible for faster decomposition. For any individual plant removed, you need to make sure that you also remove any braches that have touched the ground and layered (ie formed roots). By the way, the AMS sharpshooter shovel is highly recommended for your planting and woody plant removal activity. To make it even better, have the transition between the handle and blade reinforced with a hefty piece of steel. That shovel will become your best friend...no kidding.
TAKING CARE OF BAREROOTS
Actually, my point here was that bareroot material—while inexpensive—has significant “labor cost” downsides such as requiring more careful handling and planting, potting up to grow them to size, etc. Also, on-site nurseries are labor intensive, subject to vandalism and disturbance, often in non-ideal sites (i.e. low light). I recommend you do not bother with bareroot material. I don’t have a cost:benefit analysis to show, but would bet much money that relying on container-grown material gives you better results (i.e. better diversity, less mortality, etc) for your labor and material dollars. That strategy allows you to focus on getting plants in the ground, developing an effective firewood sale program, etc (rather than spending much time on babying the bareroot stock).
During one visit to the Forest, Clay noted a couple very large Prunus laurocerasus ("cherry laurel") shading a young redcedar. Evergreen plants are able to conduct up to 50% of their photosynthetic activity during the fall/winter months. For that reason, this particular redcedar would benefit greatly from the immediate removal of the cherry laurel; it’s all about managing light to the understory and to the plants that will benefit from that light. If cut to stumps now, the cherry laurel will resprout in spring. Clay recommends sawing the laurels off at about 4 ft above the ground and then coming back in April—when the bark is slipping—to completely remove the bark (which contains the buds used for resprouting) all the way to the ground (to prevent resprouting and to kill the plants). Otherwise, cherry laurels (English holly, Portuguese laurels, etc., generally less than 2 inches in diameter at breast height) can easily be dug out. Larger individuals can be treated with herbicide—less labor intensive, obviously. For any individual plant, you need to make sure that you also remove any braches that have touched the ground and layered (ie formed roots).
SLOPE STABILIZING SPECIES
There’s disagreement among professionals as to the role of trees in preventing or causing landslope failures. I recommend avoiding that whole dispute and plant trees and shrubs as needed to support your forest restoration. Native shrubs with aggressive underground stem (rhizome) systems are ideal for stabilizing upper soil sediments on slopes. Such species include:
DRY / MOIST
Salal (Gaultheria shallon)
Thimbleberry (Rubus parviflorus)
Salmonberry (Rubus spectabilis)
Fireweed (Epilobium angustifolium)
Nettle (Urtica dioica)
Douglas aster (Aster subspicatus)
Goldenrod [Solidago lepida (canadensis)]
Hardhack (Spiraea douglasii)
Snowberry (Symphoricarpos alba)
Naked-hip rose (Rosa gymnocarpa)
Pea-fruited rose (Rosa pisocarpa)
MOIST / WET
Slough sedge (Carex obnupta)
Salmonberry (Rubus spectabilis)
Cooley hedge-nettle (Stachys cooleyae)
Hardhack (Spiraea douglasii)
Nootka rose (Rosa nutkana)