Category Archives: Special Topics

Recommendations for Using Bare-Root Wetland Plants

by Julie Whitacre, Fourth Corner Nurseries

Fourth Corner Nurseries offers 74 species of herbaceous wetland plants available as bare-root divisions. These include several species of Carex, Juncus, Scirpus, Aster, Eleocharis palustris, Typha latifolia, Oenanthe sarmentosa, Deschampsia caespitosa, Glyceria grandis, Sparganium, Distichlis spicata, Mimulus guttatus, Potentilla pacifica, Lysichiton americanum, Veronica americana and Stachys cooleyae. Many of these species are available in large quantities (40,000-100,000). These are all grown from seed, not wild collected. Our seedlings often have higher survival rates than wild-collected plants due to less stressful harvesting techniques, and natural wetlands are not impacted. Continue reading

Elwha Revegetation Project

by Joshua Chenoweth

The historic dam removal on the Elwha River, the Elwha Ecosystem Restoration Project, is well underway. The Elwha Dam, the older and smaller dam (originally 105 feet), has already been removed and its reservoir, Lake Aldwell, has drained. As of July 1, 2012, seventy-five feet of Glines Canyon Dam, the larger of the two (originally 208 feet), has been removed. The reservoir formed by Glines Canyon Dam, Lake Mills, is more than halfway drained. As a result, we are witnessing the first full growing season in the newly exposed lakebeds! Continue reading

Biofiltration Systems for Stormwater Management

The Vegetation Component

by Julie Whitacre, Fourth Corner Nurseries

As our landscape becomes more developed, management of stormwater runoff is a crucial part of maintaining the health of natural water systems. Diminishing natural streams and wetlands are increasingly important for beleaguered wildlife populations, and we should do all we can to ensure that clean water enters these systems in natural flow patterns. Stormwater runoff often contains high sediment loads and many types of pollutants, including oil and grease, chemicals, pesticides, heavy metals, bacteria, viruses, and oxygen-demanding compounds (Interagency Workgroup on Constructed Wetlands, 2000). Treatment facilities are engineered to capture and transform pollutants in water running off roads, parking lots, and roofs so that they will not reach natural wetlands and other ecologically important habitats. The time over which water from a storm event enters streams can be extended to prevent flooding and, depending on the engineering design and site conditions, groundwater recharge is also possible. Over time, however, pollutants will concentrate in the sediment and vegetation in these facilities, creating an unhealthy environment for aquatic life. Wildlife exclusion devices may be necessary. The loss or damage to wetland habitat incurred during development should be replaced with mitigation wetlands, providing the same functions and harboring the same species diversity and biotic richness as the wetlands they replace. Mitigation wetlands require different designs and may not be used as stormwater filters due to pollution concerns. Continue reading

Rain Gardens: A Low Tech Approach to Stormwater Management

by Angela Nelson, CESCL

Thanks to Angela Nelson and 2020 Engineering for sharing their expertise on this emerging approach to stormwater management. At the end of the article, we offer a list of plants we believe would be well suited to rain garden plantings based on our experience of field growing them in our sandy loam soil.

What They Are

Raingardens are landscaped depressions designed with specific soil characteristics that are gaining popularity as stormwater filtration and retention devices in lieu of more traditional civil engineering methods. They are a part of a new approach to stormwater management termed Low Impact Development (LID). In low impact development, the landscape component of the project is integral to the stormwater management design, enhances water storage, and attenuates storm flows (Low Impact Development Technical Guidance Manual for the Puget Sound). Rain gardens are aesthetically pleasing, providing beautification to commercial and residential landscaping while at the same time treating and slowing down stormwater flows in a way that mimics natural systems. Continue reading

Native Pollinators

Matthew Shepherd & Mace Vaughan, The Xerces Society

“The conservation biology issues are not simply esoteric concerns relevant only to middle-class bird-watchers and bug-netters. These issues should strike a chord in every person who cares about where our food comes from and whether it is wholesome to eat.” — Stephen L. Buchmann and Gary Nabhan, The Forgotten Pollinators

Pollinators are among the hardest working creatures of the natural world. Pollination, the transfer of pollen grains from the anther to the stigma of the same or another flower, is necessary for plants to produce seeds and fruit. Up to 80 percent of the world’s flowering plants rely on animals – pollinators – for this transfer. Insects pollinate two thirds of the world’s crop species, whose fruits and seeds together provide 15 to 30 percent of the foods and beverages that we consume-approximately one out of every four mouthfuls. Continue reading