Soil erosion is a problem for farmers, landscapers, and anyone with a garden — and it gets a lot more pressing once the site has a real slope. Retaining walls help very little against erosion by water; the best natural, time-tested solution is planting. It controls erosion and adds value and greenery to the landscape at the same time. A few guidelines go a long way.
What to Plant, and Where
- Ground covers are good for holding fine surface soil — but on hilly ground, their roots often aren't deep enough to hold it
- Ground covers also keep loose soil from eroding in strong wind, and are best suited to plains and farmland rather than slopes
- The right ground cover depends on climate zone; sage and monkeyflower are often good choices
- On slopes and hillsides, shrubs are the better option — deeper roots hold more depth of soil
- Contour farming is a strong technique on sloped land, and gives you a chance to shape the character of the slope while you're at it
- Buckwheat and poppy-type shrubs are good erosion-control plantings, again depending on climate zone
- Large shrubs combined with evergreen trees can stabilize a hillside — the trees also act as wind barriers, protecting soil from wind erosion
- Unused land erodes easily; cover crops like beans (legumes) are a good way to prevent that
Choosing and Timing It Right
The most useful plants for erosion control are the ones with deep, fibrous roots — but it's worth planning around how long the seeds take to germinate. In the meantime, a few interim measures can hold things together without doing any long-term harm.
Mulch protects topsoil. A matting of straw works as an interim measure and is fully biodegradable. Stone or brick runoff barriers slow groundwater runoff — and double as a chance to shape the landscape while you're at it.