How to retain soil on a newly created bank.
By Gordon
United Kingdom 
Hello. We need to terrace our sloping lawn into three levels. We would like to do this by creating two banks 1.5m high at an angle of 60 degrees, each bank will be 10m long. We are hoping to use groung cover plants to retain the soil but are concerned that the banks will slip whist waiting for the plants' roots to establish. Our soil is very clay. Does anyone have any suggestions?
17 Aug, 2008
Answers
We have a 45 degree bank! We planted it with lavenders, marjoram, salvias etc, as it is in full sun and basically subsoil - quite a few plants gave up the challenge! we have a 6" board at the bottom, but have not had any soil-moving issues. To be sure - you could cover the banks in 'Mypex' or other ground-cover membrane - then plant thru it - shrubs such as cotoneaster, choisya, mahonia and chaenomeles - for semi-shade or abelia, senecio, hypericum, cotinus and genista for full sun - all would thrive in clay and take a certain amount of dryness. Or choose fast-growing perennials that make good ground cover in dry places - geraniums, lamium, ajuga,and persicaria for semi-shade or aster, geraniums, stachys and solidago for sun. Good luck!
17 Aug, 2008
This isn't much of an answer, but it could help to look at the sides of the roads as you travel along motorways and other main roads, to see methods which have been used where quite steep soil banks have been retained with mesh etc.
Good luck with your project. Maybe provide photos of your work as you go along. Would be interesting.
17 Aug, 2008