Berms can get your garden up to shape

A berm is a mounded area that is raised up from the surrounding soil to create a higher elevation with a gradual slope on all sides to the borders.

The size and shape of the berm will depend on its purpose. A berm can be used to relieve the monotony of a flat yard, as well as more serious problems like correcting water drainage or to block the view of a nearby eyesore.

Once you clarify your berm’s purpose, you can design its size and shape. A rule of thumb is to limit the height of the berm to no more than one-fifth its width. The site should allow for a gradual slope to accommodate the gradient ratio.

Most berms are about 24 inches tall or less. Aesthetically, the mound is more visually appealing if it is offset to one side instead of centered, just as varying its shape to a more interesting crescent form. A berm can be used to redirect poor drainage.

Before you begin, take the time to diagram your plan on graph paper to better visualize what you are creating. And, remember to check the site for problems related to things like large trees, utilities and the irrigation system. When in doubt, call 811, the national hotline for “Before your dig.”

Begin constructing the berm by laying down a hose along the perimeter and spraying landscape paint to mark the border edge. Clear away any debris.

Using a mix of topsoil and packed clay, build up the mound tapering out to the edge line, tamping it down as you go. Once you get your basic shape molded and smoothed down, begin to finish the last foot with good grades of potting soil mixed with compost.

Frequently spraying down the soil with water as you build will help settle it and make it easier to shape.

The berm’s purpose will guide you in the selection of plants, along with the usual consideration for growing conditions we deal with when we plant anything in our yards: light, temperature range tolerance, watering needs and the mature size of the plants. A tree might even fit on a berm if the setting is right.

An elevated row of shrubs would make a dense barrier blocking an unwanted view, adding shade or creating separate outdoor rooms for things like a patio. Plants that do best with good drainage will thrive on a berm, and your selection should focus on having good vegetation coverage year-round to minimize erosion risk.

Great resources out there to help you in your plant selection − included at the end of this column − will point you to the Superstars that have gone through trial testing and have all the facts you want to know before you buy a plant.

Three years ago, we moved to a home that has a flat yard. In the backyard, which has been fenced in with a privacy fence, the grass is in the center. The former owner used the space along the fence line to plant trees, shrubs and plants. In the back corners, they built two berms.

I had no prior experience with a berm, but had several clumps of plants I had divided from my former home. On one berm I planted iris and peonies, and on the other dwarf cannas and daylilies.

These plants typically in the first year after being moved will often skip blooming entirely or have skimpy results. However, all of the berm bunch exceeded any prior performance in 2021 and 2022. I used short tomato cages with a large diameter to prop up the peony’s heavy blooms.

My conclusion to the unexpected vigor and overcoming their resistance to being moved is the berm’s improved drainage over a traditional flower bed.

Here are some additional resources that you may find helpful: "Native Texas Plants, Landscaping Region by Region, second edition," Sally and Andy Wasowski, Lone Star Books; texassuperstar.com, Texas A&M AgriLife Extension Service; wikihow.com/Build-a-Berm.

And of course, for more information about plants and gardening in the Big Country, please like our Facebook page (Big Country Master Gardeners) or visit the Big Country Master Gardeners at bcmgtx.org for all of our future events!

Jean Seymore is a member of the Big Country Master Gardeners.

This article originally appeared on Abilene Reporter-News: Big Country Master Gardeners: Berms can get your garden up to shape