Over the Hill – Designing a NO MOW Hillside
Before: This steep little hill was hard to mow and dangerous to descend, limiting access to our client’s backyard.
Can you think of anything better to do with your time than mowing a hillside every week, all summer long? I thought so. Everyone can, because mowing hills is one of the worst chores in the landscape. When it comes to mowing hills, we’re over it and we’re here to help you get “over the hill” too.
There are many great treatments for hillside control that don’t involve mowing. Retaining walls, bee lawns, and spreading shrub gardens are three of our favorite no-mow methods to manage a hillside.
After: Our clients never have to mow this hill again. They traded their hillside lawn for a butterfly garden filled with spreading native plants and stone staircase that creates safe passage down to the backyard and patio.
Depending on the slope, retaining walls may be your best option for erosion control. Single or multi-tiered walls can add long-term stability and structural aesthetic to a space. We build walls out of stacked stone, boulders, and modular cement blocks. Versa-lok is our favorite cement block to use for retaining wall construction because it is durable, attractive, and helps us build long-lasting retaining walls.
Single or multi-tier walls can be used on slopes to create dimension and drama in the landscape. No retaining wall is complete without a planting to show it off. We love using shrubs and blooming perennials in arrangements surrounding our retaining walls. Annual plants that spread such as sweet potato vine and wave petunia can be used to dress up retaining walls when planted on the top tier as they cascade down the wall and cover it in color.
Retaining walls need to be built to manage water flow. Too often we see retaining walls built without proper drainage. Every retaining wall we install comes complete with a 10-12” drain field, drain tile, and drain plates through the face of the wall. This relieves hydrostatic pressure and allows walls to stay standing for many years without bowing or falling apart.
Retaining Walls can be used to break a hillside into planting spaces. These walls went in during phase 1 of the project. Next year, during phase 2 we’ll install perennials to dress up the space. We build cement block walls such as these as well as natural stone walls. The cement block pictured here is Versa-lok, a Minnesota manufactured, high-quality block that is made to last through the worst conditions Minnesota can offer. These super heavy blocks form a wall that locks into place to prevent bulging and cracking. Retaining walls can be a great way to hold back a slope while presenting a formal aesthetic.
Our favorite no-mow lawn option is the bee’s knees! Utilizing our Bee Lawn Rapid Transition approach, we can eliminate mowing, keep the ground covered in lawn, and feed bees all season long. Bee lawns are comprised of Fescue grass, white clover, self-heal, and creeping thyme. None of these plants need to be mowed and together they grow a healthy, happy lawn.
Our rapid transition approach to bee lawns starts with us stripping off the sod that you’re currently having to mow. Next we aerate and compost the soil to make sure there is healthy soil for your bee lawn. We complete the process by seeding, and covering the hill in a seed blanket made entirely of wood fiber. The seed blanket keeps the sprouts shaded. As the bee lawn sprouts grow up, through, and over it, the blanket decomposes over time and helps grow healthy soil.
White clover, self-heal, and thyme will form a lawn on their own without the Fescue grass if you’d prefer a lawn without any grass. All plants in this mix except for thyme can handle fairly shady conditions. When you plant a bee lawn you instantly start supporting over 75 species of MN native bees. Planting a bee lawn on your hillside will give you back your weekends and make you a hero to local bees!
Spreading plants are our friends
If controlling erosion and preventing weeds within budget are important goals for you, it may be time to explore spreading plants as landscape allies. Low maintenance spaces are controlled by strong plant communities. The spreading plants you choose to fill in your hillsides will help prevent weeds from invading. Planting combinations of strong, spreading plants will act as a living mulch, covering the ground in green and in doing so, helping to keep weeds at bay over the long term.
Blend spreading plant species with varying heights. This will provide multiple layers of canopy to both prevent light from hitting the ground which will discourage weeds, and it will slow rainfall as it lands on the ground thus encouraging soil health by slowly soaking the soil instead of pounding and compacting it with direct rainfall.
Boulders, outcroppings, and raised beds can be used to create extra drama and presentation on the hillside. Our favorite raised bed, the Round Rusted Raised Bed is an excellent way of adding structural beauty, controlling erosion, and increasing the plantable space on your hillside. We love planting annuals and perennials in these durable, elegant raised beds.
Outcroppings: Boulders decorate hillsides while presenting a solid backdrop that helps the fine textures of plant foliage stand out.
Utilize wood mulch as a short-term strategy and spreading plants as a long-term strategy to control erosion. Use wood mulch for the first couple season, and plan to have the hill consumed by multiple layers of spreading plants within a few years’ time. Some of my favorite spreading plants that can be used in both sun and shade on the hillside together include:
Gro-Low Sumac, 2-3’ tall. This is an outstanding groundcover shrub that is short but spreads about 8 feet wide. It grows in most any soil in full or part sun. Excellent purple-red foliage in the fall. Drought resistant and perfect for holding a hillside or mass plantings.
Low Bush Honeysuckle, 3’ tall. Lovely low mounding, deciduous shrub with colorful bronze-green foliage. Yellow flowers in spring turn red-orange during summer. Attracts songbirds who eat seeds and fruit.
Grey Dogwood ‘Muskingum’, 3’ tall. Foliage emerges deep red. Creamy white clusters of flowers in May-June, followed by white berries loved by birds. Strong spreader that makes a phenomenal groundcover. Tolerates pollution, drought.
Taunton Yew, 3’ tall. Taunton is a dense, low-growing yew which branches freely. Grows in sun or shade. Birds love to hide in yew branches. Requires well-drained soils. New growth emerges yellow and ages to dark green.
Bee Balm, 4-5’ tall. Monarda is a favorite of hummingbirds, bees, and butterflies. Bee balm is one of the favorites of Minnesota’s state bee the Rusty Patch Bumblebee. Lavender blooms with trumpet shape add a robust presence in the mid-summer garden.
Pennsylvania Sedge, 1’ tall. We love this sedge as a lawn alternative because of its fine textured leaves and a creeping habit and because it does well in sun or shade. Planted one foot on center, it will fill in to form a dense low growing turf that never needs mowing. Requires a well-drained soil.
Daylily, grows 2-3’ tall. Daylilies are often overlooked by new gardeners and homeowners and thought of as over-used. This is quite unfortunate because daylilies are a full season of delight. First, every part of the plant above ground is edible, flowers, stalks, and leaves. Next, if daylilies weren’t as common in the landscape, we’d all see how amazing their form and color is. Long slender foliage pushes up stalks that hold yellow, orange, red, and maroon flowers. Blooms most of the growing season.
Yarrow, grows 1-2’ tall. Yarrow is very popular with pollinators. Grows naturally at the edge of the woods, and performs stunningly in the part-sun garden. Highly medicinal plant,
Hosta, grows 1-3’ tall. Hosta is one of the bees favorite perennials. With varieties that span the season in bloom time, and so many types and colors of foliage, hosta is a shade garden favorite. For extra drama, Empress Woo and Blue Angel are two favorite varieties. Hosta Plantaginea is a very fragrant variety that deserves a place within smelling distance of a walkway or garden path.
Vinca Minor, 3-6” tall. Strong spreader, the definition of low-maintenance. Vinca minor has lovely, evergreen, broadleaf foliage and violet colored flowers; it is an excellent ground cover and is perfect in and around shrubs and trees.
Pachysandra, 6” tall. Pachysandra is an excellent ground cover in sun or shade. Works well under trees and shrubs. Sweet white blooms in early spring.
Plan for Changing Conditions: Spreading ground covers Pachysandra and Vinca Vine form the base layer while spreading shrubs Taunton Yew and Gro-Low Sumac form the middle layer. We chose this plant mix because all these plants will happily transition from full sun to full shade as the six White Pine trees planted between them grow and start to tower above the space. Succession plantings such as this provide a long-term, low-maintenance hillside.
Rusted Round Raised Bed: The addition of this steel raised bed brings a whole new dimension to the hillside. This front lawn hillside was recently planted with spreading ground covers shrubs including and Tom Thumb Cotoneaster, Phlox Divaricata, and Canadian Ginger. Inside the Rusted Round Raised Bed we installed Bleeding Heart, Lobelia Cardinalis, and Bee Balm. Over time the steel raised bed will rust to form an attractive patina. We’ve used these raised beds for 15 years now and they hold up better than any other form of raised bed on the market.