How to Plan a New Native Planting Bed This Fall

Fall is one of the best times of year to start a new native planting bed. Cooler temperatures and more reliable rain give new plants time to settle in and grow roots over the winter, so they're ready to take off in spring. The good news is you don't need a huge space or a big budget to get started. A small, well-planned bed can do a lot for wildlife and give you a strong foundation to build on for years to come.

Here's how I'd approach planning a new bed from the ground up.

Step 1: Prepare the area

Good prep is the difference between a bed that thrives and one that's overrun by weeds by next summer. If you're working with Bermuda grass (and most of us in Nashville are), this step matters more than any other.

Bermuda spreads by underground rhizomes, and it will happily creep right back into a new bed if any are left behind. There are a few ways to deal with it:

• Dig it out by hand. For a small area, you can prepare it manually . Dig at least 8 inches deep, then shake out all of the soil to remove every rhizome you can find. Any pieces of bermuda left behind will resprout in the spring. It's hard work, but this method means you can plant this fall.
• Smother it. Smothering can take a year or two to fully work. Cover the area with a deep layer of mulch, (ideally 2 feet deep), and leave it in place for at least a full year. If you're starting now, you can mark out an area this fall and let it smother through next growing season with plans to plant next fall.
• Spray it. Herbicide needs to be applied during Bermuda's active growing season, roughly May through September, when the grass is actively growing and most vulnerable. You can use grass-selective herbicide or pure glyphosate. Always read and follow the label directions for mixing, application, and safety. If you missed that window this year, plan to spray next summer and plant next fall.

Before you dig, call 811 (or visit call811.com) to have underground utility lines marked.

An area around 5' x 5' is a great size for a first bed. It's manageable to prep by hand, affordable to plant densely, and easy to keep an eye on while it gets established.

Once you've chosen your spot, mark out the shape of the bed with a garden hose, marking paint, or a sprinkle of flour or sand. This makes it easy to see how the bed will look in the space and adjust it before you start digging.

Step 2: Get to know your site and soil

Before you pick your plant palette for the bed, take some time to observe the spot you've chosen. You'll want to note three things:

•         Light. How many hours of direct sun does the area get? Full sun, part shade, and full shade will each call for a different set of plants.

•         Moisture. Does the area stay wet after a rain, or does it get dry and cracked in the summer? Is it at the bottom of a slope or up against a hot wall?

•         Soil. What are you working with underneath?

Most of our soil here in Nashville is alkaline clay, because we generally sit on limestone here in the Central Basin. That might sound like a challenge, but it's exactly what our native plants evolved to grow in!  It does mean you should generally avoid acidic-soil loving plants more common to the mountains of East Tennessee (I'm looking at you, azaleas!)

If you're dealing with new construction where the topsoil has been scraped away, you may want to mix in a little leaf compost to add some life back into the soil. Otherwise, no amendments are needed. Native plants prefer our natural soil, and adding fertilizer actually works against them. It leads to leggy, scraggly growth that's weak and more likely to get munched by deer, rabbits, and other wildlife.

Step 3: Build your plant palette in layers

Once the area is prepped, the fun part begins: choosing your plants. For a 5' x 5' bed, about 15 to 25 plants is a good target, depending on the mature size of the species you choose. That's enough to plant densely so the plants grow together and shade out weeds over time.

You can use shredded pine bark mulch in the first year while things fill in, but the long-term goal is a living mulch: layers of plants that cover the ground themselves. Here's how I think about those layers:

•         Anchor shrub or tree. A woody shrub or small tree gives the bed structure in all four seasons, as well as providing habitat and food for wildlife. Beautyberry or spicebush work well in shade, and St. John's wort or Ninebark are great choices in sun.

•         Grasses or sedges. Don't skip this layer! Grasses and sedges fill in the gaps, cover the ground, and give the bed four-season interest when the flowers are dormant.

•         Flowering perennials. Choose a mix of species that bloom in spring, summer, and fall so there's always something flowering for you and for pollinators.

Design tip: When grouping your plants, stick with odd numbers such as 1, 3, and 5. Odd-numbered groupings are the most appealing to the human eye and give the bed a more natural look.

Example: A part shade bed

If I were planting a bed in part shade, I'd anchor it with American witch hazel (Hamamelis virginiana), which blooms with fragrant yellow flowers in late fall and early winter, when almost nothing else is flowering. Underneath it, I'd plant a matrix of sedges with flowers and evergreen texture tucked in for each season.

Choose hairy alumroot if you want semi-evergreen foliage through the winter, or hairy wood mint if you'd like more summer blooms for pollinators.

Example: A sunny, dry bed

For a bed in a hot, sunny, dry spot, I'd anchor it with a dwarf ninebark or shrubby St. John's wort. Then I'd layer in a native bunchgrass and a mix of flowers that carry the bed from spring through fall.

Make it your own

These are just examples. Any of these plants could be swapped for other flowering perennials based on your site conditions and your preferred color palette.

The trick is to choose plants that want to grow in the conditions you already have. When you match the plant to the site, you won't need to baby them over time. Once they're established, they'll take care of themselves other than pulling out the occasional weed or keeping the edges of the bed clean.

Add cues to care

A densely planted native bed can sometimes look different from a traditional lawn or landscape, so it helps to give neighbors (and passersby) a few signals that the space is planted on purpose and cared for.

•         Dig a trenched edge. This is also the easiest way to keep Bermuda grass at bay. Dig a trench around the edge of the bed, then run a string trimmer along that edge a few times a season whenever you see the grass starting to creep in. It keeps the Bermuda out and gives the bed a clean, intentional border.

•         Add a sign. A small sign lets neighbors know the bed is there to support bees, butterflies, and other wildlife. You can certify your yard and order an official sign through Tennessee Smart Yards or the National Wildlife Federation's Certified Wildlife Habitat program.

Getting certified through either program is easy! If you have questions or would like help with the process, you're welcome to reach out to me at emily@culversrootgardens.com.

More resources

Free design plans and inspiration

•         Less Lawn More Life is a challenge to swap out a piece of your lawn for native plants, with ideas and support to help you get started.

•         Wild Ones offers free native garden designs for different regions. This plan for Lexington, Kentucky falls within the Interior Plateau region, the same region we're in here in Nashville.

Seed options if your budget is tight

If your budget doesn't allow for live plants this year, you can still sow seed once your area is prepared:

•         Project Milkweed offers free milkweed seed.  You can sign up to get notified next time seeds are available.

•         The Tennessee Environmental Council's Pollinator Initiative offers affordable pollinator seed mixes appropriate for our area.

Ready to go bigger?

If you want to plan something larger than a 5' x 5' bed, Homegrown National Park has a great step-by-step guide to designing a native plant landscape.

Come shop the Neighbors for Native Plants sale

If you're ready to start a new bed, or want to add density and layers to an existing one, come see us at the Neighbors for Native Plants sale on Sunday, November 1, from 11am to 1pm at Cornelia Fort Airpark. Culver's Root Gardens will be there alongside other local growers, with plenty of plants to get your fall garden beds off to a great start!