Fearsome Threesome: What about weeds?

One of the biggest challenges in the ongoing care of outdoor spaces is the presence of invasive weeds. Here are three of the worst offenders at Waikiki Springs Nature Preserve. Remediation of these invasive and destructive plants is part of our ongoing stewardship of the Preserve.

Poison hemlock: Reminiscent (in my opinion) of east coast Queen Ann’s Lace, every part of this dangerous plant is poisonous. According to the Spokane County Noxious Weed Control Board, “Always wear gloves and protective clothing when working with Poison Hemlock. All parts of the plant are poisonous. It contains alkaloids which cause neuromuscular dysfunction and leads to death from respiratory paralysis. Do not allow animals to eat live or dry plant material. Do not let children play in areas with known infestations.” The plant can grow up to 12 feet tall. The leaves are shiny green and can be up to two feet long. The umbrella-shaped clusters of small white flowers have five petals and bloom from June to August.

Spotted knapweed: This is probably one of the most prolific and recognizable invasive plant species on many of the popular trail systems in the Inland Northwest. They can grow up to three feet tall. The leaves and stems are covered in coarse hairs that make the look gray-blue. The early June buds produce 25-35 flowers. Their sturdy taproot makes them drought-tolerant and the seeds can remain viable in the soil for up to ten years.

Diffuse knapweed: Similar to spotted knapweed, diffuse knapweed reproduces by seeds. The flowers are white and sometimes a pale purple. The bigger it gets, the harder it is to pull with its determined taproot. Mowing when the flowers are in their early stage can help reduce the spread of seeds, and pulling the plants when they are young nd in small patches helps reduce their prevalence.

If you see our stewardship crew out there mowing, spraying, or digging, know that they are doing it with the best interest of our native plant ecology, the quality of the water in the Little Spokane River, and the health and safety of our dedicated trail users top of mind.

Much of this year’s stewardship work at Waikiki Springs, from invasive weed removal to native plant restoration, has been funded by a generous grant from Clearwater Paper. This grant has allowed the Conservancy to purchase tools, trail and activate crews of volunteers, grow and transplant native plants and shrubs, and engage more Volunteer Land Stewards to help protect this beautiful place.

Thank you for recreating responsibly! If you notice issues with widespread invasive plants at the nature preserve, please let us know through this form.