Establishing Native Wildflower Cover Crops in Virginia Piedmont Apple Orchards

Commodities

• Fruits: apples

Practices

• Crop Production: cover crops

Native wildflower cover crops can represent the foundation of a new vegetation management program in orchard floors, solving the challenges of intensive orchard floor management while creating additional benefits for producers, ecosystems, and communities. Native wildflower ground covers would transform orchard floor management by allowing growers to plant selected native wildflower species that are adapted to local growing conditions and have life cycles that integrate with orchard management (ideally senescing ahead of apple harvest and leaving few crop residues in the fall through mid-winter). The proposed project would directly address the program focus areas of beneficial insect habitat, alternative (cover) crops, soil organic matter building/protection/management, increasing the sustainability of existing farming practices, and agroforestry.

This project is a regional adaptation of research that I performed at the University of Oregon, where my research group had been developing wildflower cover crops for Willamette Valley hazelnut orchards for over five years. Before that, I was a weed scientist and cover crop researcher in orchard systems in Central California. I have begun selecting and planting wildflowers for my apple orchard in Central Virginia, and the proposed project will allow me to more effectively and economically establish wildflowers adapted for our region. In October 2025, I planted single-species wildflower plots in a portion of my orchard to begin evaluating candidate wildflower species, and I will use these initial plots to develop one of the seed mixes used in the proposed research. This currently ongoing species selection experiment is essential for identifying appropriate wildflower species for our climate. Wildflower establishment was a major concern in my research on the West Coast, and additional information about establishing and growing Mid-Atlantic wildflowers is essential.

By establishing a mix of early and middle season blooming species, orchards can maintain floral resources throughout the spring and early summer to support beneficial insects and natural pest enemies. In Central Virginia, Piedmont meadow-adapted wildflowers can grow alongside existing grass species, creating a competitive environment for grasses. Whereas existing practices require frequent mowing during the spring and summer to reduce grass biomass, wildflower mixes would compete with grasses to reduce biomass accumulation and reduce mowing frequency.

Ideally, this system would dramatically reduce mowing to just one or two cuts per season for wildflower termination and to create accessible orchards ahead of apple harvest, while naturally suppressing weeds through competitive ground cover. Native wildflower ground covers would transform vegetation management in orchards to deliver multiple agricultural, economic, ecological, and cultural benefits. For producers, native wildflowers could reduce the intensity of orchard floor management, thereby reducing equipment operation hours, lowering maintenance costs, and decreasing exposure to agricultural chemicals. These factors will improve economic and physical well-being.

Ecologically, agricultural landscapes would be improved by enhanced biodiversity, reduced erosion, and improved water quality in local watersheds. Native wildflower ground covers enhance soil structure and water infiltration while reducing erosion and soil loss. The diverse plant community increases biodiversity, creates essential habitat for pollinators, and supports natural pest control through enhanced beneficial insect populations. This approach simultaneously reduces equipment use while improving soil health. The system creates opportunities for premium pricing through ecological certification programs while enhancing farm aesthetics for agritourism potential.

This project aligns with growing consumer demand for sustainably produced foods while preserving and enhancing the region's agricultural traditions. New sustainability practices in orchards could increase development of sustainable orchards systems, thereby increasing consumer access to sustainably grown, local apples that contribute to Central Virginia's heritage of apple production. Beyond apples, wildflower cover crops could support regenerative production of a number of perennial crops across the South, improving access and sustainability of culturally important foods. The proposed research will take place in Central Virginia apple orchards, but ideally could be translated into other orchard systems across Virginia and the Southeast, as well as to vineyard systems.

By enabling sustainable production of local apples, the project enhances regional food security while maintaining working agricultural landscapes in diverse wildland matrix landscapes in the Piedmont. The shift from intensive mechanical management to an ecological approach demonstrates how agricultural production can work with natural systems to achieve both economic and environmental goals. This project will develop and demonstrate practical, economic methods for transitioning to this improved management system, providing a model for sustainable orchard floor management throughout the region. The long-term vision of this project is to increase knowledge about orchard cover crops generally, and wildflower cover crops more specifically, in our region, ultimately accelerating the adoption of sustainable vegetation management systems for orchard floors.

The study will evaluate methods for establishing wildflower seed mixes in a small apple orchard in Central Virginia, with a focus on healthy wildflower stands and minimizing seed cost. The study site features a high density apple orchard, with heirloom cider apple varieties on dwarfing rootstocks supported by a trellis system. I will test seeding rate and establishment timing using one commercially available wildflower mix and one wildflower mix I am currently developing at my site. In a small plot, randomized complete block experiment, I will plant each of the two seed mixes at high and low planting rates in both the spring and fall. A fully factorial design allows for analysis of main effects and interactions between seed mix composition, seeding rate, and planting date while controlling for spatial variability.

I will establish 18'x10' plots in the orchard alley between tree rows. These plots will encompass one orchard alley with three trees on each side (tree spacing in this high density orchard is 6' within row and 10' between rows). Each plot will receive one combination of seed mix, rate, and timing treatments. The study will be replicated in four blocks to account for environmental gradients within the orchard, with each block containing a nontreated control plot and all eight treatment combinations (two seed mixes × two planting rates × two timings) randomly arranged within the block. This design will result in 36 experimental plots in total and 5,760 sq ft planted with wildflowers. The experiment has been designed to fit into available space my existing apple orchard including buffer space between plots.

The seed mix treatment includes a commercial seed mix and seed mix I am currently developing. The commercial seed mix will be the VA Southern Piedmont Upland Meadow Mix from Ernst Seeds (Meadville, PA), which includes several native grass species in addition to over a dozen wildflower species. The other seed mix will consist of four to eight wildflower species available from Ernst that I will select based on their performance and survival in single species plots I already established in fall 2025. Seeding rate treatments will include a high and low rate at approximately 75% and 125% of the manufacturer's average seeding rates for wildflowers, to be determined after final species selection. Native wildflower seeding rates can vary significantly, and my goal is to select seeding rates that are agronomically relevant and will provide information about the cost effectiveness of wildflower cover crops. Establishment timings will include both fall (October) and spring (February) sowing, as both timings may be appropriate for wildflower establishment, based on seed dormancy, site conditions, management factors, and weather. Plots will be mowed and lightly cultivated to ensure good soil to seed contact before seed are broadcast at each establishment timing.

Each treatment combination will be assessed for seedling emergence, stand density, and flowering using replicated, standardized vegetation sampling. I will perform systematic plant surveys by quadrat sampling with 0.5m² quadrats in each plot. Plant surveys will begin in April 2027 following wildflower germination and continue monthly through apple harvest (six surveys April-September) to track wildflower emergence, growth, and flowering phenology, followed by crop residues and potential regrowth after wildflower termination. An additional round of plant surveys in March of 2028 will identify any germination or regrowth from wildflowers in the year following the wildflower planting. In each survey, I will observe species-specific presence/absence, vegetation coverage, flowering status, and abundance, while also recording the same information for any weed species. Repeated sampling will reveal both short-term establishment success and longer-term population dynamics.

In addition to plant surveys, I plan to evaluate the outcomes of wildflower cover crops using soil sampling. I will collect soil samples from each plot three times during the project cycle: in the fall before the first wildflower planting (to establish baseline data), during wildflower peak flowering (to understand the effects of actively growing wildflowers), and in the fall after wildflower termination (to assess potential lasting effects). Soil samples will be sent to Waters Agricultural Laboratories (Warsaw, NC) for nutrient analysis. Additionally, I will employ in-field microbial biomass tests from microBIOMETER (Everett, WA) to assess impacts of wildflowers on soil microbes. Microbial biomass is an increasingly important indicator of soil health, and a pilot dataset generated by this study could provide background information for future projects.

Seed cost and establishment success remain major barriers for widespread practice of seed-based native plant propagation. It is critical to generate high-quality, field-based information that is relevant for farmers and increases the practicality of growing native wildflowers as non-crop plants. This project is designed to create some of the first practical information about wildflowers in perennial cropping systems on the East Coast.