Starting with seeds for an imperiled butterfly

Restoring Mardon Skipper Habitat at Vesper Meadow

by Tuula Rhebhan, The Understory Initiative

and Jeanine Moy, Vesper Meadow Education Program

Project Area and Context

Vesper Meadow is one of the many highland meadows strung across the Cascade-Siskiyou mountain region, sitting at approximately 4,500 feet above sea level, at the headwaters of Little Butte Creek, which flows north and west to meet the Rogue River at the valley floor.

Like most of the meadows in the region, it has been severely impacted by cattle grazing and water diversions over the last century, but is now a demonstration site for community-led restoration and education programs. A variety of scientific, artistic and biocultural restoration efforts meld at the Vesper Meadow Restoration Preserve, a community hub since 2019, with the goal of restoring a seasonally wet meadow, Tribal camas tending and harvest practices, and habitat for a multitude of plant and animal species.

We have a special emphasis on rare species like the Oregon Vesper Sparrow and Klamath Mardon Skipper butterfly, both species that are declining and imperiled. Intensive work has taken place around Latgawa Creek (formerly Dead Indian Creek) to restore riparian habitat by mimicking beaver activity, planting willow, and re-starting natural ecosystem processes that existed before the property’s 150-year tenure as a cattle ranch. The wet meadow conditions are crucial for many species, including the Mardon skipper that requires plants that like living in wet meadow conditions.

A Klamath Mardon Skipper documented in early monitoring at the Vesper Meadow Restoration Preserve. pic 2018 John Villella.

In addition to restoring the wet meadow conditions required by the Mardon skipper, we continued to develop specific efforts to restore host plants in meadow areas to support Mardon Skipper at Vesper Meadow.. The current Mardon Skipper restoration project area is situated between the property structures (barn and cabin) and (Dead) Indian Memorial Road, a main road that connects Ashland to Hyatt Lake, Lake of the Woods and other higher elevation areas. The area is approximately 4 acres in total, includes seasonally wet areas, and dominated by non-native meadow foxtail grass (Alopecurus pratensis). However, some of the original native plant populations remain in this area, including yampah (Perideridia spp.), biscuitroots (Lomatium spp.) and camas (Camassia quamash). Crucially, neighboring areas within Vesper Meadow have similar habitat with a much higher proportion of native plants and greater species diversity. Mardon skipper are sometimes seen in these places, though they are in very low numbers.


Restoration Goals

Observing the plant communities and habitat structure in the Vesper Meadow “intact” areas of Mardon Skipper habitat provided some key insights into the needs of Mardons and other butterfly species. Over the last several years we have been working with local biologists to monitor Mardon skipper populations and the state of their meadow habitats. Biologists from the Medford District BLM and local biologists partners like John Villella, Norman Barrett, Dianne Keller, and Jeanine Moy have made key observations about Mardon habitat requirements and a list of plant species that the Mardon needs for egg-laying and nectar (food!). 

Native bunchgrasses are essential food for Mardon skipper caterpillars. As adults, they need the space provided by the open growth pattern of bunchgrasses to move about close to the ground – they don’t fly high. Small native wildflowers become crucially important when Mardons enter their adult stage; they feed or “nectar” on species like Plectritis congesta (seablush) and Bistorta bistortoides (bistort). Critically, Mardon Skipper can not live in meadow foxtail grass, which was planted at Vesper Meadow as food for cattle and grows very tall and dense. 

The dimension of time is another important consideration of this habitat – the Mardons fly and seek nectar in June, so only flowers blooming during that time window can be utilized. They overwinter as pupa, again on bunchgrasses and near the ground (Life Histories of Cascadia Butterflies by David G. James and David Nunnallee, Oregon State University Press, page 388).

Understanding Mardon Skipper habitat needs helped us answer the question “What are we restoring?” In 2024, with support from the Greenfield Hartline Habitat Conservation Fund, Vesper Meadow Education Program and The Understory Initiative were able to develop a seed mix and restoration strategy to make more suitable habitat available for the Skipper, with the hope of stabilizing their population and allowing them to thrive once again in the southern Cascade mountain range. 

Site Preparation

The first step toward building Mardon Skipper habitat at Vesper Meadow was to eliminate the existing vegetation cover, especially meadow foxtail grass. Rather than using herbicide, we opted to use plastic tarps to smother the grass, leaving the tarps in place for a full year to kill not only the green, growing part of the grass but also its extensive and persistent root system. These silage tarps (example here) are black on one side to absorb solar heat, which raises the temperature under the tarp high enough to kill vegetation but not sterilize the soil. They are thick (5 millimeters) and UV-coated, which extends their lifespan to about five years. Under normal use they will not disintegrate into microplastics like woven tarps. They are effective in killing most annual weeds and lawn grasses. 

Silage tarps have been used at Vesper Meadow since 2019 to convert pasture areas into pollinator meadows and native plant demonstration gardens, starting close to the barn and house structures and moving outward on both sides of the driveway. Each fall the tarps are removed, areas are reseeded with native plants, and the tarps are placed in a new area. In fall 2023, tarps were placed in the Vesper Meadow pasture area described above to cover about 18,000 square feet (0.41 acres) for future Mardon Skipper habitat.

Other resources describe how to smother invasive plants with tarps, so we won’t detail the process here. However, we should note that meadow foxtail grass provides a specific challenge to the tarping method of invasive plant control, with its large volume of biomass forming a thick layer of thatch underneath the tarp. Because native seeds need to contact bare soil in order to germinate, the thatch must be removed before seeding can take place in the fall. In most years, this has involved hand raking, and many hours spent by employees and volunteers to do the hard work of thatch removal. Depending on conditions, thatch can be raked into piles and burned. An experiment with burning the thatch in-place in fall 2023 resulted in fire catching onto un-tarped, dry standing dead grass – a 3-acre grass fire that fortunately did not spread. 

In the future, Vesper Meadow may be able to implement a prescribed fire or cultural burn to remove meadow foxtail thatch, but it wasn’t logistically possible in the fall of 2024. This effort also represented the largest square footage we would attempt to seed in one year, and at Vesper Meadow, the seeding window can be very narrow, occurring after the first fall rains but before the first snow. To save time, avoid missing our opportunity to seed, and reduce labor costs, we decided on a tractor-mounted rake as the best solution available. 

Utilizing a landscape rake to remove invasive pasture grass thatch and prepare for seeding.

This rake has a nine-foot span and was mounted on a vintage International Harvester tractor that was able to navigate the tarped areas nimbly to keep soil compaction in the meadow to a minimum. We found that the rake attachment was the perfect tool to lightly remove the long strands of dead grass, exposing the rich soil beneath. Once we got the hang of moving a maximum amount of organic material off the area with each tractor pass, the areas we raked with this method were available for seeding within less than an hour for each of the three areas tarped. We estimate that this saved about three days of labor by a 2-person team.

To summarize, site preparation for this seeding effort consisted of tarping the 18,000 square foot area for one year with silage tarps, and raking thatch with a combination of tractor and hand rakes to expose bare soil. No herbicide or other control methods were used. Because of previous efforts, we are confident that this preparation method is sufficient to reduce meadow foxtail and other invasive plants significantly, allowing native plants to establish. 

Seed Procurement

Seeds are essential for landscape-scale understory restoration projects; planting containerized plants over such a large area is costly and would result in lower species diversity in the end project. Based on the existing research and observation at the Meadow, we developed an ideal seed mix to balance the Mardon Skipper’s need for native bunchgrasses as nesting habitat and caterpillar forage, as well as small early/mid-season native wildflowers for nectaring adults. 

From the longer list of desired species, seed procurement limitations determined what actually went on the ground and in what quantity. With advice from Vanessa Robertson-Rojas, who procures plant material for restoration projects across the Rogue Basin with The Understory Initiative, we were able to obtain the necessary volume of bunchgrass seeds from Pacific Northwest or Northern California sources, and planned to wild-collect as many seeds as feasible from the local area to introduce local genetics. While large seed suppliers like Larner Seeds and Pacific Northwest Natives are great for supplying things like Festuca romerii (Romer’s fescue) and Danthonia californica (California oatgrass), two of the Mardon Skipper’s favorite bunchgrasses, they don’t typically carry a large diversity of wildflower species. 

Fortunately, the Rogue Native Plant Partnership had available a few pounds of Plectritis congesta and Wyethia angustifolia (compass flower) seed sourced from regionally local genetics. Another must-have forb on our list was the Bistorta bistortoides; this is not available either from larger suppliers or the local RNPP sources. Fortunately, this plant grows in abundance at Vesper Meadow. We focused our available budget on wild-collecting this seed, as well as seed from local Plectritis and the bunchgrasses. Volunteers and our summer Healing Landscapes intern played a critical role in getting the seed collected. 

Tuula guides volunteers in preparing the Mardon skipper seed mix for sowing in the prepared meadow area.

[table of seed mix with quantities]

In addition to this base mix, some additional wild-collected seed was added to some of the areas to increase forb diversity with species like Potentilla (cinquefoil), Perideridia (yampah) and Lomatium (biscuitroot).  

Overall, this seed mix was grass-heavy, and applied lightly. This seeding strategy will attempt to replicate the structure of habitat areas utilized by Mardon skippers, where plenty of open space allows them room to take off, land and complete their bunchgrass-dependent life cycle. There will be some downsides to this strategy: The perennial grasses are much slower to establish than forbs and annual grasses, creating an opening in time when undesirable plants may re-colonize the area. While Plectritis is an annual forb that establishes quickly and reseeds readily, Wyethia is a large perennial plant that may take years to grow and produce flowers, and not much is known about Bistorta’s time to maturity or pioneering abilities in a restoration context. This combination of forbs will, for the first few years after seeding, only provide nectar to pollinators during the short early-summer window when Plectritis is blooming.

To mitigate these risks, Vesper Meadow staff and volunteers will keep a close eye on the seeded areas, practicing early detection and rapid response to invasive plant infestations. And continued maintenance of existing restored native plant meadows at Vesper Meadow will ensure that all pollinators, including Mardons, will have access to nectar and habitat resources across the entire bloom season. (Starting in April and wrapping up in October, often with snow falling on some long-lasting Madia blossoms!)

Seed Application Method

Community volunteers spread the Mardon skipper seed mix on a rainy fall day 2024.

As described above, this seed mix was applied at 20 lbs/acre. To avoid overseeding (“streching” the mix) and to provide seeds with some protection from birds, the mix was mixed 50% with granulized clay, sold as “pure clay” cat litter in stores. Teams of 5-10 volunteers assisted with seeding, so some additional accommodations were made to ensure that the seed mix was applied evenly across each of the three rectangular areas that had been prepared for seeding. 

First, in each area, we marked out transects for individual volunteers to walk. These were evenly spaced 5-10 feet apart, depending on the number of volunteers. Each person was given a small bucket containing an equal proportion of the seed/clay mix, and provided a demonstration of how densely the seeds should be scattered. We found that by emphasizing a “light hand” method, we could avoid overseeding and ensure that each individual’s bucket was distributed evenly across their transect. Volunteers took less than five minutes to walk their transect, throwing handfuls of seed. If seed was left in the bucket at the end of the transect, they were instructed to go back to “fill in” areas that appeared to have been underseeded.

Seeds were then hand-raked in. This was the most time-intensive part of the seeding process, taking 1-2 hours of work by the team. The final rake is crucial, however, to ensure seed-soil contact and protect seeds from predation. Because some of the thatch material inevitably remained in the seeded area, we did not mulch over the top with straw or other material. 

Lessons Learned and Future Actions

Preparing these areas for seeding and procuring the seed mix provided an excellent learning opportunity for restoration practitioners at The Understory Initiative and Vesper Meadow. Here are some of our key take-aways:

• Labor needs are always greater than expected, even with low-input methods. Although spreading out a tarp and leaving it in place for a year seems like an easy task, many staff hours were required to check on the tarps and manage them, especially during the high-wind seasons of winter and spring. Moving a 50x100’ tarp (plus several dozen sandbags) requires muscle and strategy to coordinate a team of six or more people. Habitat restoration without herbicide will always rely on low-cost or free labor, which may not be available in all situations. 

• More local seed sources are needed. Farming native seed on a large scale greatly reduces the costs and increases accessibility of native plants for restoration work. However, all plants adapt to their specific habitat; using seeds that are adapted to different temperature regimes, soil types, pollination timing and more means that those plants will forever lack certain competitive advantages at this particular location. Restoration practitioners need to leverage funding and plan ahead to improve the availability of locally adapted native seed to ensure restoration success.

• Embrace Adaptive Management and Risk Preparedness: Field restoration is inherently unpredictable. Our experiment with burning thatch—which led to an unexpected 3-acre grass fire—underscored the importance of conducting thorough risk assessments and having contingency plans. Environmental conditions, including narrow seeding windows and variable weather patterns, remind us that flexibility is key. Being prepared to adjust methods and continuously monitor outcomes is essential for navigating unforeseen challenges and ensuring long-term restoration success.

Conclusions

Our work at Vesper Meadow demonstrates that restoring habitat for the Mardon Skipper is both a challenging and an hope-giving endeavor. By employing non-chemical methods to remove invasive meadow foxtail using silage tarps, and through careful seed application, we have laid the groundwork for re-establishing native plant communities critical to the butterfly’s lifecycle. These efforts, while labor-intensive, have proven effective in preparing the land for a carefully crafted seed mix designed to meet the specific needs of the Mardon Skipper.

Throughout this project, we have seen firsthand the value of collaboration. The integration of expertise from the Bureau of Land Management, The Understory Initiative, Vesper Meadow stewards, Rogue Native Plant Partnership, independent researchers, and dedicated volunteers has enriched our approach. By combining commercial seed sources with wild-collected material, we ensured that our seed mix not only met the ecological requirements of the target species but also reflected the genetic diversity of the local flora. This blended approach is essential in creating resilient habitats that can withstand future ecological challenges.

While the initial outcomes are promising, we recognize that long-term success depends on continuous monitoring and adaptive management. Future efforts will focus on maintaining the balance between native plant establishment and invasive species control, refining seeding techniques, and exploring additional management practices such as prescribed burns. These steps will be pivotal in ensuring that the restored habitats not only support thriving populations of Mardon Skippers but also contribute to the broader ecological integrity of the region.

Big thanks to the Greenfield-Hartline Foundation, and the local BLM Resource Advisory Council for supporting this work!