How OSMP Utilizes Native Seeds for Ecological Restoration
Open Space & Mountain Parks: Native Seed Program Overview
Helianthus annuus, or the common sunflower, seeds in development
Photo credit: Unknown
The City of Boulder Open Space and Mountain Parks Department (OSMP) uses native plant species in our ecological restoration program, as called for in the OSMP Long Range Management Policies and in support of the Master Plan ecosystem health and resiliency strategies. Over the years, we have used commercially available seeds for native species that occur in the Boulder area and have gradually expanded the collection and use of local native seeds on OSMP land. Purchased commercial seeds are often from seed sources in other parts of the western United States or even the eastern U. S. and Canada and may not be as well adapted to the Boulder area climatic conditions as local “ecotypes” of the same native species. In addition, seeds for many native species are not available commercially or can be very expensive. Our premise, based on experience in the field and scientific literature, is that locally sourced native plant material will have the best long-term success in restoration sites. The effects of climate change on Front Range ecosystems may have variable impacts on local native species, and our understanding of how species function in ecological restoration will likely change based on research, monitoring, and experience in the field.
Seeds collected with volunteers and other staff from more than 35 species of native grasses, forbs (broad-leaved plants), shrubs, and trees have been processed and stored for use in ecological restoration projects across OSMP. Examples include:
Wetland and riparian (streamside) revegetation following major flooding, non-native tree removal, trail construction, and as part of habitat enhancement.
Part of forest restoration after disturbances from tree thinning.
Prairie restoration following trail construction, undesignated trail closure, or mine and oil extraction closures.
New trail construction, trail rerouting, and undesignated trail (unplanned social trail) closures.
Invasive non-native plant removal areas.
Revegetation of agricultural old fields.
Post-disturbance revegetation in utility right of ways
Golden aster seeds and flowers. (Heterotheca villosa)
Photo credit: Unknown
Our restoration goals center around recreating or enhancing native plant species diversity and structure in disturbed areas so that they serve as good functional habitat for many wildlife and plant species and become resistant to non-native species invasion over time. Additional focus is on restoring appropriate hydrology, stabilizing and improving soil conditions, and managing non-native invasive plants. Species selected for seed collection are usually common on OSMP land and play a role in early plant establishment in disturbed sites or long-term plant community building.
Photo credit: OSMP Staff
Community Involvement and Partnerships
As mentioned, our dedicated volunteers and paid staff help acquire local native plant seeds and other materials. We partner and contract with Wildlands Restoration Volunteers (WRV) and organize seed collections through the OSMP Volunteer Services program. This volunteer work is a great way for community members in the Boulder Valley and vicinity to learn more about and to take part in caring for their Open Space. OSMP’s native seed program is possible due to this support from the community.
Photo credit: OSMP Staff
OSMP’s native seed program grew from partnering with Boulder County Parks and Open Space (BCPOS) on grants and learning from the County’s already established seed program. We continue to share knowledge and collaborate in ways that help strengthen both programs. OSMP has also sponsored agency partnership seed collections on OSMP land that provide seeds to sister agencies such as Longmont Open Space and Ft. Collins Natural Areas Program. These collections contribute to Front Range collaboration on developing local genetic plant material sources for ecological restoration.
What Happens to the Collected Seeds?
Wild blue flax seeds and flowers. (Adenolinum lewisii)
Photo credit: Unknown
Once collected, seeds are checked for non-native plant material and dried. Dried seeds may be cleaned by removing non-seed material so that the seeds can be incorporated into a restoration mix. Volunteers and other staff help clean seeds, and sometimes seeds are sent to a U. S. Forest Service cleaning facility. To determine the percentage of viable seeds in a seed lot, testing may be done at the Colorado Seed Lab, within Colorado State University’s College of Agricultural Sciences. Knowing the percentage of “pure live seeds” in a batch of seed allows us to calculate how much bulk seed of each tested species to include in custom seed mixes. Seed mixes are developed by staff.
Photo credit: OSMP Staff
Some collected seeds may be sent to a seed growing facility to be cultivated under contract in an agricultural-like setting. In this way, relatively small amounts of collected seeds can be grown out and result in large seed amounts. This is referred to as seed increasing. Seed increasing helped us acquire enough switchgrass seeds for the many riparian and wetland restoration projects after the 2013 flood. Recently, OSMP has started to contract small seed increase projects with agricultural lessees.
Photo credit: OSMP Staff
After drying and in some cases cleaning, collected seeds are stored in OSMP’s climate-controlled seed storage unit for future use. To help preserve optimal seed viability for as long as possible in this small building, the temperature is held constant at 50 degrees Fahrenheit, and the relative humidity is maintained at 20%. Currently, the shelves are brimming with bags of seeds!
More about OSMP Native Plant Use
Hand collected shrub and tree seeds, or cuttings are often sent to a plant nursery to be propagated and grown out. OSMP later purchases potted woody plants and maintains a small holding nursery for plant material. Management of the nursery entails the potting of purchased bare root shrubs, caring for shrubs grown under contract, propagation of hand collected cottonwood and willow poles, and the weeding, watering, and other maintenance of all plant materials. Cottonwood and willows pole cuttings are collected in the late winter or early spring before leafing-out occurs, held in water under dark conditions to prevent bud break, and then planted in riparian and wetland habitats. Woody material and wetland plugs are planted around the system in various restoration projects and used to augment previous seeding and plantings.
Seeds are also collected by the OSMP agricultural program to use for enhancing species diversity in agricultural fields. These projects are designed to improve soil health and create pollinator habitats, along with other ecosystem services.
Photo credit: Omer Pearlman
Protecting Native Plant Populations: Seed Collection Requires a Permit!
Please note that collection of seeds or other plant material requires a permit on Open Space and Mountain Parks and other public lands. In Boulder, municipal statutes prohibit collection of plants or other natural or cultural items. OSMP collection permits are typically issued for research purposes only. Some small native plant nurseries have been issued seed collection permits. Permits enable staff to coordinate and track collections, and to minimize negative impacts on native plants, wildlife, and other natural values. Boulder has many rare and sensitive plant species that are protected on OSMP land from off-trail trampling, displacement by noxious weeds, collection, and other threats. Over-collection of plants or seeds depletes seed banks (seeds in the soil) and can compromise the viability of local populations.
Additional Resources:
Information about OSMP Collection Permits:
OSMP Research Permits - City of Boulder
Some Resources for Using Native Plants to Conserve Water, Benefit Pollinators & Other Wildlife:
Gardening with Native Plants - Colorado Native Plant Society
