While planting trees and shrubs on a hillside may at first seem like a job for the pros, it can be a DIY project for homeowners too.
If you’re landscaping a hillside with trees or shrubs, proper planting is key. Taking a few extra steps during planting will ensure that your landscaping stays put and grows strong. When planting on a slope, the roots and trunk should be straight. The ground should be changed so water goes to the plant’s roots, not straight off.
Learning how to plant trees on a slope can be a daunting task, but this guide gives you six steps to planting trees, like fruit trees, on your hillside. Keep reading so you can add planting trees on a slope to your lawn care toolkit.
Step 1: Build Terrace
Create a flat area or small terrace in your slope, about three times the diameter of the root ball of your tree or shrub. You can make this terrace by cutting into the hillside and building out of the slope. This will likely require a retaining wall or rocks and a combination of cutting into and building out the slope.
The less you disturb the original soil, the more stable your slope will be. The finished terrace should be firm enough to stand on while working.
Step 2: Plant a Tree or Shrub
Now that you have a nice flat spot, plant your tree or shrub with the trunk upright and vertical and the root ball at the proper planting depth. Plant your seeds near the middle of the terrace and try to leave some unbroken soil on the downhill side to avoid problems.
If the plant is too close to the bottom edge of the slope, the roots may become exposed due to erosion. On the other hand, if the plant is too close to the top of the slope, it may become buried by soil or debris tumbling down the hill.
Step 3: Create a Berm to Hold Water
As you backfill around your tree or shrub, put the excess dirt on the downhill side to create a small berm to catch water as it runs down the slope. Make sure not to pile extra dirt directly on the root ball, but make a half-donut shape around the plant instead.
Step 4: Apply Mulch
Put a couple of inches of mulch around the tree or shrub to help hold the dirt and berm in place, keeping the mulch a few inches away from the trunk. If you’d like, you can first put down a layer of landscape fabric or mesh using garden staples. Be sure to choose non-slippery landscape fabric, so your mulch won’t slide off.
Step 5: Water the Plant
Water your tree or shrub well to help settle the soil. Fix any problems that arise after the first watering to make sure the planting is stable.
Step 6: Monitor the Plant
Keep an eye on the tree or shrub for a few months to make sure the soil is settling properly, water is being captured, and the roots are staying in place. Make sure the roots aren’t getting buried by falling debris. Keep the berm in place for at least a year or two until the plant is well-established. Reapply mulch as needed to help hold water.
Final Thoughts on Hillside Planting
Planting a tree or shrub on a hillside is a DIY project that’s fairly simple for homeowners. That said, you proper planting is necessary for your tree to live a healthy life.
Start by building a terrace, then plant the tree or shrub and backfill with soil while creating a berm. Once you’ve filled in the topsoil, cover it with about 2–3 inches of mulch and water the plant. New plants need monitoring, so be sure to check on them regularly.
This can be a simple project for homeowners to do for smaller trees, like fruit trees. For larger trees, I suggest hiring a professional because it’s safer.
FAQs About Plating on a Slope or Hillside
How do you plant trees or shrubs on a steep slope?
There are a few steps to planting trees or shrubs on a steep slope.
Start by choosing an appropriate species for the area you live in. The tree or shrub you pick should be adapted to your climate and soil conditions, and have strong root systems since it’s being planted on a slope.
Then you’ll need to dig a hole large enough to fit the root systems and build up flat areas into the slope to reduce erosion and help water retention. Position the tree upright and backfill with a mix of soil and compost, and stake it up if you need to.
Once the tree is planted, staked, and supported with soil, apply a layer of mulch around the base to help water retention and prevent weeds. Water the plant regularly.
What is the best ground cover for a slope with trees?
The best ground cover depends on climate, soil type, and the angle of the slope the tree is on. When deciding on a ground cover, consider the compatibility with the existing trees on the slope, soil retention ability, maintenance, requirements, and local invasive species laws.
One option is using native plants and grasses because they are deep-rooted and adapted to local conditions. Creeping juniper is shade-tolerant, drought-tolerant, and forms a dense mat.
Periwinkle is fast-growing and tolerates many climates, while bugleweed is low-growing, and spreads quickly. Sedum is drought-resistant and works well on rocky slopes, while cotoneaster is a woody ground cover with good erosion control.
Creeping phlox is a pretty flowering option for full-sun slopes, and for shaded moist slopes, consider using moss.
What is a sloping garden?
A sloping garden, also known as a hillside garden, is a landscape design built on a slope. These garden designs allow for terraced layouts, retaining walls, and cascading plant arrangements unlike traditional gardens. However, these gardens have drainage challenges. As water runs down the gardens sloping borders, erosion and dry spots tend to happen at the top.
