Bringing your lawn back to life by converting turfgrass to native wildflowers
Article and illustrations by Amanda Mikyska and Nash Turley
Turfgrass lawns are ecologically simple and support very little biodiversity, in this example just a few non-native plants and invertebrates, and if you’re lucky a bird now and then. By contrast, a diverse patch of native wildflowers provides the foundation for a complex and diverse food web with a wide variety of pollinators, herbivores, and predators.web with a wide variety of pollinators, herbivores, and predators.
If your backyard is anything like mine, it looks a lot like your neighbor's lawn. The grass is green and always cut shorter than four or five inches. Or maybe you live in a building or complex with a courtyard space filled with turfgrass and low maintenance mulch and shrubbery, adding no nutritional value to the insects and critters that have always lived there. Palms decorate the perimeter of houses and buildings, and generally, it looks clean, a concept that has seeped out of our homes to encompass our outdoor space. Like our homes, backyards have become far more desirable when protected from the vast diversity of bugs that run the world. Porches are screened in to keep out bugs, and if bees manage to nest in the backyard, they may be conquered at night with pesticide. However passive, the decision to fill our landscapes with non-native plants stifles the diversity of native bugs because they do not provide proper nutrition of habitat for them.
It is unnerving that it is not only possible to tour the yard without interacting with bugs, but is expected. Plants make the vast biodiversity on Earth possible because they are the foundation of food webs. They convert sunlight into energy and then are consumed by bugs, which are consumed by animals, passing nutrition and energy up the food chain. A turfgrass lawn dissolves the first link in the web because it is a wasteland where few bugs can survive. Some lawns are even more meticulously manicured by hired professionals to exterminate weeds, built-in irrigation systems, and a chemical diet that makes the lawn grown greener and more luscious. Actions that polish front lawns are contagious in neighborhoods, and when every neighbor participates, the scale of the problem becomes enormous.
Habitat loss is the greatest single threat to biodiversity generally and native plants and pollinators specifically. The vast expanse of turfgrass lawns contribute to that habitat loss but also have the opportunity to be restored to benefit native plants and pollinators.
In addition to being a biological dead space, turfgrass lawns are a massive resource sink. Turfgrass covers about 63,000 square miles in the United States, an area about the size of Georgia (Milesi et al. 2005). If this scale does not strike you, consider that just in this area, 20 trillion gallons of water are used every year (Milesi et al. 2005), compared to the USDA estimate of 27 trillion gallons that are used for all crops grown in the U.S. per year, combined. Turfgrass does not provide the resources to support many pollinators and other insects (Dale et al. 2020), and any insects that do live around turfgrass might be killed by the 60 million pounds of pesticides used in homes and gardens each year (EPA 2012).
The widespread loss of habitat, partly because of lawns, is the leading cause of insect declines. A recent synthesis of studies from around the world found that insect populations are declining by 9% every decade, suggesting there could be only half the insects now than in the 1970s (van Klink et al., 2020). During this time, over 3 billion birds have disappeared from North America, and the loss of their primary source of food, insects, is thought to be an important cause (Rosenberg et al. 2019). There are similar troubling patterns for bees. Of the native bee species in North America that have been studied, over half of them are in severe decline (Kopec & Burd, 2017).
Often when we hear about the plight of bees, it is about colony collapse of honeybees and "Save the Bees" merchandise. This coverage has raised a lot of awareness about pollinators, but honeybees are not at risk of extinction, and they should not be the focus of environmental conservation. Honeybees are non-native species from Eurasia and have been moved around the world by people as we have with cows and chickens. They are economically important in agriculture, but in the wild, they are quite problematic. They can reduce the numbers of native pollinators by competing for resources (pollen and nectar) and by spreading diseases and parasites (Mallinger et al. 2017). The species that are struggling to survive and will cause adverse environmental impacts if they die are the 300 native bee species to Florida and 3,600 native bee species to the U.S.
With all of this concern about insect declines and the disappearances of pollinators, what can we do? Just as lawn space can be the biggest threat to insect habitats, it has the potential to be the greatest asset. Converting patches of turfgrass to native wildflowers provides the pollen and nectar that pollinators need. The ecology is pretty simple: converted lawn-to-wildflower plots have a greater abundance and diversity of native flowers, which supports a greater abundance and diversity of insect pollinators (Blaauw & Isaacs 2014). Even a small plot (6 feet long, 6 feet wide) of native flowers can attract and help feed a wide diversity of native pollinators and other insects. The native plants feed insect pollinators, herbivores, and detritivores. And those insects can be food for many other animals, including birds as they make the grueling journey from South America to Canada. Native plants are the key to making your small patch of the Earth a part of a functioning ecosystem.
This 6-step method for converting turf to native wildflowers is easy and effective at killing the existing non native vegetation and suppressing weeds. This gives your new native plants a good environment to establish.
Convert a patch of turfgrass to native wildflowers
Now that you're ready to convert a patch of turfgrass to native wildflowers, here's how to make your plot beam with life. Start by prepping your plot three months in advance to get rid of the non-native plants that live there now. Choose at least a 6-by-6 foot area in your yard. Most pollinator-friendly wildflowers that are native to Florida love sunshine, so a plot that gets at least a half-day of full sun is best. This will help your flowers grow and allow you to plant a wide variety. You'll need to have cardboard, mulch, and water. Cardboard isn't hard to find, but you'll need enough to make three layers over your plot. This is your chance to do a little dumpster diving for the environment! Cardboard bins are plentiful behind dollar stores, but avoid colored cardboard, and remove any tape, staples, or stickers.
Mow any existing grass or weeds, then thoroughly water the ground. Next, put down cardboard with lots of overlap between each piece so the grass can't poke through. Shoot for three layers of boxes (if they are all boxes folded in half) or six individual layers. Water the plot again, soaking through all layers of cardboard on your plot. Finally, weigh down the cardboard with a thick layer of mulch, and let the plot sit for three months or more. This is enough time to kill the grass and for the cardboard to break down. While the cardboard is doing the hard work for you, it is time to decide which native wildflowers you want to plant. Most big brand stores don't sell native plants, so check out the Florida Association of Native Nurseries to find the nursery closest to you (https://www.floridanativenurseries.org/). You can always start your plants from seeds in pots if you're a native plant rockstar. When selecting plant species, got three rules to keep in mind:
Go Native! Given the support native plants provide the local ecosystem, this almost goes without saying. But to hammer the point home, native plants from your part of the world have a good chance of thriving on their own with no water or chemical inputs. Because many insects are specific to the plants they've coevolved with, native plants provide better resources for native insects and will support more biodiversity (Burghardt et al. 2009)
Maximize Variety! An ideal pollinator garden has plants flowering throughout the year with a variety of flower shapes and colors. Many pollinators are active only during a small part of the year, so if your garden is not in bloom at that time, the pollinators have to find another food source. Therefore it is important to plant early, middle, and late blooming species. Other pollinators are specialized to a specific family or species of plants, or specific flower shapes, so try to get flowers that vary in size, shape, and color.
Right Plant, Right Place! Planting the right species in the right place will make both the plant and its pollinators happy. When selecting your wildflowers, look for species that require the soil and sun conditions similar to where you plan on planting. In addition to the needs of the plant, ensure you are planting something that works with your maintenance and aesthetic preferences. For example, if you want short flowers, be sure to check the height range of the species that interest you.
Three months have passed, and you've got your native flowers picked out, now it's time to plant! Dig holes through the mulch and cardboard (it will probably be very decomposed by this point) and transplant your potted plants. Planting in roughly a 1-by-1 foot grid works well, so about 25 plants for a 6-by-6 foot plot. Make sure to give them a good watering after planting. Hopefully, the mulch and cardboard will suppress the weeds long enough to give your native plants a good head start, and it will help keep your plants from drying out after planting. In the long run, mulch is not necessarily a friend to pollinators because the majority of native bees nest in the ground. So, we recommend you let the mulch break down and keep the ground layer natural going forward.
Of course, if the smothering method seems too slow or complicated, there is a much simpler approach. Just dig out a section of turfgrass and transplant or sow seeds right away, it's that simple! Be careful with seed mixes as many of them have non-native species in them. Luckily here in Florida, we have the Florida Wildflower Growers Cooperative, a great source to buy native seeds (http://www.floridawildflowers.com/). Whichever method you choose, keep in mind that for the first year your garden plot might need some care, like occasional water if they look droopy, or some weeding so your flowers do not have to compete for resources. After the plants are healthy and established in your plot, they should not require watering and hopefully will be more robust than any non-native plants that show up.
With each lawn-to-wildflower plot, we chip away at the Georgia-sized expanse of turf that blankets the U.S. Each patch of turfgrass we convert is a step towards changing the culture from one that values uniformity and sterility to one that values complexity, diversity, and life. You can be a leader in this cultural change. The time is now for you to convert a biological dead zone into a thriving ecosystem. Your native plants will feed fungi and beetles with their roots, bees and flies with their flowers, caterpillars on their leaves, and birds with their seeds. That's just the beginning; all those plant consumers support more life, birds, lizards, spiders, wasps, and on and on. Native plants are the foundation of ecosystems and the key to supporting the rest of the glorious biodiversity on Earth. We can draw in the wonders of nature to our lawns, and all that's needed is some cardboard, a few native plants, a vision of a complex and verdant landscape, and the motivation to bring it into existence.
About the Authors
Nash Turley is an ecologist, naturalist, and the founder of Lawn to Wildflowers (www.lawntowildflowers.org). He works as a post-doctoral researcher at the University of Central Florida, advancing the movement returning outdoor spaces to native plant species. Nash also creates videos and podcasts aimed at communicating ecological research and natural history to a general audience, which can be found at www.nashturley.org.
Amanda Mikyska is a Lab Manager at the University of Central Florida, and assists on projects including Lawn to Wildflowers and studying viral integration in Hymenoptera. Amanda also covers new research in neuroscience for the scientific networking site Labroots (www.labroots.com).
References
Blaauw, B.R., Isaacs, R. 2014. Larger patches of diverse floral resources increase insect pollinator density, diversity, and their pollination of native wildflowers.Basic and Applied Ecology. 18(8), 701-711.
Burghardt, K. T., Tallamy, D. W., & Shriver, G, W. 2009. Impact of native plants on bird and butterfly biodiversity in suburban landscapes. Conservation biology, 23(1), 219-224.
Dale, A. G., Perry, R. L., Cope, G. C., & Benda, N. 2020. Floral abundance and richness drive beneficial arthropod conservation and biological control on golf courses. Urban Ecosystems, 23(1), 55-66.
Environmental Protection Agency. Pesticides Industry Sales and Usage 2008 - 2012 Market Estimates. Table 3.2. https://www.epa.gov/pesticides/pesticides-industry-sales-and-usage-2008-2012-market-estimates
Milesi, C., Running, S. W., Elvidge, C. D., Dietz, J. B., Tuttle, B. T., & Nemani, R. R. 2005. Mapping and modeling the biogeochemical cycling of turf grasses in the United States. Environmental management, 36(3), 426-438.
Kopec, K, & Burd L. A. 2017. Pollinator in Peril: A systematic status review of North American and Hawaiian native bees. https://biologicaldiversity.org/campaigns/native_pollinators/pdfs/Pollinators_in_Peril.pdf
Mallinger, R. E., Gaines-Day, H. R., & Gratton, C. 2017. Do managed bees have negative effects on wild bees?: A systematic review of the literature. PloS one, 12(12), e0189268.
Rosenberg, K. V., et. al. 2019. Decline of the North American avifauna. Science, 366(6461), 120-124.
USDA. Results from the 2018 Irrigation and Water Management Survey. https://www.nass.usda.gov/Publications/Highlights/2019/2017Census_Irrigation_and_WaterManagement.pdf
van Klink, R., Bowler, D. E., Gongalsky, K. B., Swengel, A. B., Gentile, A., & Chase, J. M. 2020. Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances. Science, 368(6489), 417-420.
This article originally appeared in Palmetto, the magazine of the Florida Native Plant Society, FNPS.org © The Florida Native Plant Society