What’s Greener than Grass?

Pollinator lawns! Grass lawns are a common sight across the United States. Grass lawns may look nice and green, they’re not always the most environmentally friendly option for your yard.

A pollinator lawn, like the one growing on the northeast corner of the National Museum of Natural History, is made up of grass and flowering plants that attract pollinators. These lawns require less water, fertilizer, and maintenance than traditional grass lawns, yet they can still be used for picnics, relaxing, and yard games!

Why did Smithsonian Gardens grow a Pollinator Lawn?

Turf is Tough on Pollinators.

It’s a common practice to mow grass lawns before they bloom and go to seed. This makes lawns a wasteland for pollinators that need flowers to feed on and places to nest.

Grass lawns also deplete the soil of nutrients and are susceptible to disease. These problems lead to the use of chemicals and fertilizers which can pollute groundwater and harm wildlife. In fact, Americans use more than 90 million pounds of pesticides on their lawns and gardens every year. That’s the equivalent weight of around 450 blue whales – the largest animal on earth.

Pesticides contain toxins that not only kill beneficial insects, but can also run off into lakes and rivers and harm marine life.

Who does the Pollinator Lawn help?

Pollinators and Plants: A perfect match!

Plants in a pollinator lawn have co-evolved with pollinators over many, many years to form perfect partnerships. Pollinators select flowers to feed on based on their shape, size, scent, and color. While going from one flower to another, pollinators carry pollen that fertilize the plants. A win-win combination!

  • The clouded yellow butterfly (Colias croceus) has specialized mouth parts that enable it to reach inside self-heal’s (Prunella vulgaris) tubular flowers.
  • The tiny sweat bee (Auguchlora pura) is attracted by the aroma of creeping thyme’s (Thymus serphyllum) small flowers.
  • The endangered rusty patched bumble bee (Bombus affinis) is attracted to white flowers, like those of Dutch White Clover (Trifolium repens).

It’s time to think outside the lawn!

There are plenty of pollinator-friendly alternatives to grass lawns, including pollinator lawns, native flower beds, vegetable gardens, trees, and shrubs.

How did Smithsonian Gardens create its Pollinator Lawn?

Smithsonian Gardens is shifting away from traditional, chemically dependent turf and striving for a sustainable alternative. The site chosen for the Smithsonian’s Pollinator Lawn had been maintained as a turf lawn until the spring of 2020. It is partially shaded, has high foot traffic, and had existing patches of Dutch White Clover.

Based on research on local pollinators and plants, a pre-mixed blend of fall fescue, Dutch White Clover (Trifolium repens), self-heal (Prunella vulgaris), creeping thyme (Thymus serphyllum), common blue violet (Viola soraria), Bluets (Houstonia longifolia), and Virginia Springbeauty (Claytonia virginica) seeds was added to the existing turf. Seedling plugs of Pussytoes (Antennaria plantigifolia) and Virginia Strawberry (Fragaria virginiana) were planted as well.

Smithsonian Gardens’ fall-season turf care regiment includes soil aeration to remediate soil compaction, overseeding with our pollinator lawn mix, and spreading organic granular turf fertilizer.

How can I make a pollinator-friendly lawn at home?

Because each region in the United States varies due to its climate, pollinator lawn components can fluctuate widely. It is best to begin planning a pollinator lawn by contacting your region’s agricultural extension office to get information on which turf varieties are suitable for your climate.

  1. Assess your site
    1. Look for the amount of sun, shade, and water the site gets.
    2.  Review the condition of the existing turf.
    3.  Conduct a soil test to determine what nutrients are present and the water holding capacity of the soil.
  2. Decide what type of pollinator lawn you want to grow.
    1. Do you want some turf and some flowering plants?
      1. Can you keep some of the existing turf (is it healthy)?
    2. Do you want just flowering plants?
      1. There are many ways to clear an existing area of vegetation so that it can be re-planted. Try one that doesn’t require chemicals like covering the plants with cardboard to smother them.
  3. Once the site is prepped and a turf seed mix and/or plants are chosen (typically, fall seeding is recommended):
    1. Aerate the soil to reduce compaction.
    2. Amend the soil as needed according to soil test recommendations.
    3. Apply the seed mix per the manufacturer’s recommended seeding rate.
    4. Depending on the amount of bare soil, an organic topdressing of light compost or straw may be needed after seeding to keep wildlife from stealing the seeds and to help hold in moisture.
    5. Apply a chosen fertilizer per the manufacturer’s recommended rate (Smithsonian Gardens often uses an organic granular fertilizer).
    6. Lightly water the area often (in high heat or drought, this may be once every day) until you start to see seeds sprout.
    7. As temperatures drop, watering needs will also taper off.
    8. Through late fall into winter, the roots of the seedlings will continue to establish themselves. Come springtime, you will start to see the seedlings flourish.
    9. Mowing should not be needed as frequently as that for a regular turf lawn, nor should the plants be cut as short as a traditional lawn. Remember, you WANT the plants to flower, so that may mean only mowing every 2-3 weeks at a mowing height of 5 inches or higher depending on the plant species.

Resources:

Pollinator Lawns – Michigan Pollinator Initiative (msu.edu)

Pollinator Lawn – Blue Thumb