Planting a Bank: Covering a Slope With Roots That Hold Soil
Planting a bank means covering a slope with shrubs, perennials plus groundcovers. Their roots bind the soil while leaves break the force of rain.
The short answer
Mississippi State University Extension notes trees plus shrubs form a tight net of roots that binds soil plus slows runoff. Iowa State advises planting along the contour lines. NC State notes mulch covering at least 85 percent of the soil slows runoff on slopes. Cover bare soil until roots fill in.
Which plants work well on a bank?
MSU notes an open, sunny meadow holds soil better than lawn. Lawngrass binds soil but does little to slow runoff. Iowa State notes plants of mixed heights scatter heavy raindrops.
| Cover | Role | Source note |
|---|---|---|
| Shrubs plus trees | Bind soil | MSU |
| Sunny perennials | Hold slope once grown | MSU |
| Mixed heights | Scatter raindrops | Iowa State |
| Straw mulch | Slows runoff | NC State: 85 percent cover |
Source: MSU, Iowa State plus NC State Extension.
How do you plant on a steep slope?
Iowa State advises small planting terraces cut from the upper side of the hill plus placed on the lower side. Each terrace should be 2 to 3 times wider than the root ball. Plant on the contour.
How do you stop erosion while plants grow?
Iowa State notes the most erosion happens while plants establish. Erosion blankets help here. NC State notes straw is the lowest cost mulch but blows away without a tackifier.
How to: step by step
- Gauge how steep the bank is.
- Lay erosion control blankets if needed.
- Cut small level terraces across the slope.
- Plant along the contour lines.
- Mulch around plants.
- Water deeply until roots establish.
Troubleshooting
Soil washes between plants: bare gaps. Add mulch or a blanket.
Gullies appear: runoff. MSU advises stones or check dams in the gullies.
Lawn washes away: shallow roots. Use shrubs or meadow plants.
Read garden microclimates, planning an outdoor garden layout plus mulch for cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- Gardening on slopes and hillsides, Iowa State University Extension and Outreach
- Do you have any tips to help with gardening on slopes?, University of Maine Cooperative Extension
- Mulch options for erosion control on construction sites, NC State Extension
- Gardening on steep slopes, Mississippi State University Extension
FAQ
Should a slope be terraced before planting?
UMaine Extension describes raised beds terraced along the contours. They are 8 to 12 inches tall plus no more than 4 feet wide.
Do groundcovers hold soil well?
Iowa State notes plants of mixed sizes scatter raindrops plus cut surface erosion. UMaine suggests Dutch white clover between beds.
Can straw mulch work on a steep bank?
NC State notes straw is used on slopes less than 2:1. Steeper or longer slopes can make straw fail.
Can grass grow on a steep bank?
MSU notes lawngrass binds soil but does little to slow runoff. Heavy rains can wash away turf, roots plus all.
What is a steep slope?
MSU Extension defines a steep slope as land rising more than twenty percent. Slopes under that are usually more stable.
