Battling Weeds with Bison Manure


The Nature Center is always looking for natural ways to battle invasive species. Bison manure is probably one of the more interesting.
Road sign and mulch on top of the ground
Current status of the front entry island project, awaiting fall transplants. Photo by FWNC&R Staff.

If you visited the Nature Center in March, you may have noticed large piles of manure on the entry island. To some, this may be a little off-putting, but, under the surface, a lot is happening! Manure is very high in nitrogen, which is commonly added to landscapes as a fertilizer. But when used in high concentrations or in combination with other factors, such as shading, it can actually cause plants to die. That was the plan for the bison manure at the front entry island.

Many of you are probably familiar with Bermudagrass (Cynodon dactylon), a common turf and pasture grass that has aggressively escaped and invaded roadsides, coastlines, flowerbeds and landscapes. Bermudagrass is one of the many invasive species that we battle here at the Nature Center, and it was starting to take hold in the front entry island bed. Our volunteers with the Restoration Greenhouse program are very passionate about using natural processes in our restoration projects, which was the inspiration to find alternative control methods beyond herbicide. Bermudagrass is a beloved pasture/turf grass due to its ready response to fertilizer and irrigation; however, it is not shade tolerant. Applying nitrogen to Bermudagrass causes it to put all of its resources into above-ground growth. If sunlight is then restricted, its ability to photosynthesize is blocked, essentially causing it to grow itself to death.

Synthetic nitrogen fertilizer can be expensive, especially when working within a city budget. This encouraged us to find resources on site. Bison manure, like cattle manure, can be very “hot” (high in nitrogen). With the goal of “burning” the grass, this was the perfect solution! Our Restoration Greenhouse volunteers were very enthusiastic to ride around the bison enclosures to pick up as much manure as we could to spread atop the Bermudagrass. The bison manure took care of the nitrogen application, but we still had to shade it out; otherwise, it would be encouraged to grow. Using some weed barrier that we already had on hand from previous landscaping projects, Restoration Greenhouse volunteers covered the entire area and pinned down the edges to keep it tight. Another volunteer group, Natural Guard, helped by clearing Chinese privet (Ligustrum sinense, another invasive species on the property) along a fence line and chipped it to produce mulch. Natural Guard and Restoration Greenhouse volunteers worked together to haul the mulch and dump it at the entrance island for us to spread. We applied about one to two inches of mulch on top of the bison manure and weed barrier cloth.

People collecting bison manure in a field with bison
Nature Center Restoration Greenhouse volunteers gather bison manure in the East pasture. Photo by FWNC&R Staff.

Because the manure is so high in nitrogen, we are unable to immediately plant that area. For now, we must wait for soil microorganisms to break down the manure and “cool” down before we can do a full planting in the fall. Working with natural processes can take time, which can be frustrating. These days, it’s very common to want immediate results, but working with natural processes does not always allow that. Restoration can take time and requires patience, but in the end, it is worth the wait.

We appreciate your patience and understanding of our “messes” as we work with nature to restore what has been damaged. We also love and appreciate all our volunteers and staff who work hard and are always helpful and enthusiastic to try creative solutions.

Julia “Roze” Shipman, Naturalist Resource Specialist, Fort Worth Nature Center & Refuge

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9,800 Days Ago

We are sad to say goodbye to someone who has left an indelible mark on the Nature Center over the past decade. Please join us in wishing former Nature Center Manager Rob Denkhaus the best as he transitions to an exciting new role with the City of Fort Worth.

Thank You to Our Sponsors

A very special thank you to those who helped the Friends honor Bob O’Kennon and celebrate our 50th anniversary at Fort Worth Wild 2024.