Rebecca Stup: Recruiting flowers to combat weeds, promote biodiversity

How do wildflower strips benefit nature?

We know that wildflower strips will improve biodiversity on farms. And not only by attracting and creating habitat for beneficial insects and pollinators. We’re also seeing a lot more small mammals in those plots, small game, and especially, more birds. There’s also aesthetic value. We’re planting Black-eyed Susans, Virginia wild rye, purple comb flower, sunflowers, partridge pea – it’s all very showy, and pollinators love that. Research we published in 2024 found that at unmanaged field margins, there were 0-0.3 bees per 3x5 meter quadrant, whereas wildflower strip quadrants of the same size averaged 1.3-4.7 bees. 

Do wildflower strips ever cause problems for farmers? Do they become weeds themselves?

A lot of farmers have concerns that the flowers are going to become weeds. Black-eyed Susans in particular do behave aggressively and will move outside the zone where you want them. But in the really heavily managed area that is the field itself, it’s not a concern. If you’re tilling and spraying in a conventionally managed field, these perennials will not be able to handle that. Another concern is that these wildflower strips will act as a reservoir for weeds. But the first year data shows that is not the case. 

How difficult is it for farmers to adopt this practice?

We’re trying to make it as easy as possible for farmers to do this. At Aurora Farm Field Day this past summer, we demonstrated the research and passed out wildflower seed packets to farmers. Another project in the DiTommaso lab looked at putting seeds in pellets about the size of corn seeds, so farmers could use existing equipment to plant. And the U.S. Department of Agriculture offers funding and technical advice to help farmers adopt this and other practices that support pollinators. 

How long does it take for wildflowers to establish and out-compete problematic weeds?

About two years, if you mow the margins in the first year. We had one plot planted with wildflower seeds and then left unmanaged, and one plot that was planted and then mowed every so often for weed suppression. Especially in field margins, all the very aggressive agronomic weeds will absolutely choke out the planted wildflower perennials in the first year. But if you mow so the weeds don’t go to seed, the second year, the perennials begin to dominate. 

In your four years working on this research, what has surprised you most?

In the multi-year planted areas, I’m surprised by the amount of native perennials showing up that weren’t part of our wildflower mix. We’ve seen things like common milkweed – which wasn’t part of our mix – growing in the wildflower strips, but not so much in the unmanaged controls. I’m not sure why. Perhaps ecological succession is at play, building up a habitat that’s more conducive to native plants in general. I’m glad to see the milkweed occurring there, though. In August, we published a paper on conservation and management of common milkweed in farm fields, as it is both an ecologically important plant and a challenging agricultural weed, though not an especially competitive one. 

Interested in majoring in plant sciences? Learn more. 

This research has been funded in part by Federal Capacity Funds managed by Cornell AES. Those funds, available in all 50 states, support research on agriculture, environmental protection and community wellbeing. It is being carried out at two Cornell AES-managed farms: Musgrave Research Farm in Aurora, NY and one of the Campus Area Farms in Ithaca, NY. 

Krisy Gashler is a freelance writer for the Cornell University Agricultural Experiment Station.