Plant the Slant: Tips for Gardening on Slopes
- 2 days ago
- 2 min read
by Eileen Ellsworth
Depending on its position and angle, planting a slope isn’t always easy. But the rewards can be considerable. When your work is done and your slope face is filled with new colorful, water-absorbing, soil-retaining natives, it’s a tremendous feeling of pride and accomplishment. Your garden will display like a picture on a wall.
Erosion is, of course, the main issue. There’s no such thing as a “one-size-fits-all” plan for slope gardening. Slope contours, angles, sun exposure, water flow, and soil health all differ. And for sharply angled slopes, landscape engineering strategies like check dams and terracing may be necessary for erosion control. But for most slopes, native plants are all that are needed. Their deep and extensive root systems interrupt the chain of events that cause erosion, and once established, they attract local wildlife to boot.
Remember there is no need to tackle the entire slope at once. Get started on just one section and see how it goes with these steps:
Identify the existing native trees, shrubs, and plants on your slope, and leave them be. Use iNaturalist, Picture This, or some other tool to help you. You will plant around and between them, which is helpful. Their existing structure offers a frame to fill, and their shade will help the new plants establish themselves and better survive the summer heat.
Identify the non-natives and remove them, then amend the soil with some compost and perhaps new topsoil depending on the extent of erosion.
Purchase new native plants. For best results, choose plants that spread quickly, have broad leaves to catch the rain, and a strong winter presence. Also, slopes are drier than flat plots because of their drainage, and moisture down a slope occurs at a gradient. They tend to be drier at the top and moister towards the bottom, so consider some drought-tolerant plants in your purchase.
Plant everything and then mulch. While mulching is never ideal in that it tamps down native plant spread as well as weeds, natives take their time getting established. First year they “sleep”, next year they “creep”, third year they “leap.” Mulch will help protect your plants until they’ve “leaped” sufficiently to cover the ground and grip the soil.
Water your plants frequently, especially in July and August. They won’t make it through the first year without enough water. A soaker hose is one way to keep the water from just running off.
As the season progresses, revisit your plan. Perhaps add duplicates of plants in early autumn that did especially well.
Here are some additional resources for your consideration:
The Northern Virginia Soil and Water Conservation District offers an excellent list of erosion control plants here.
Plant NOVA Natives has a webpage dedicated to erosion control and suggested plants here.
Request a free site visit from the Wildlife Sanctuary Program of the Northern Virginia Bird Alliance and ask for suggestions.
