Gardening on rocky mountain sides presents a set of challenges that are tough on the body as well as the plants. All is not lost though, if you prepare carefully.
Gardening on Rocky Soils
There are many areas of the country where American gardeners have to contend with a soil surface covered in rocks. Gardening in rocky soil is definately a challenge. Typically you find these conditions near to, or on top of, mountains such as the Adirondacks, The Rockies and other high ranges. These mountains and their foothills are held up by various rock forms that also run under the garden. Clearly this requires a specific and arduous form of garden preparation in comparison to the Midwest where the ground is generally flat and rock free.
Major rock removal is likely to be impractical or even impossible but there is hope. Surface rocks weather over the years and you will find a layer of soil above. How long they have been exposed and how many rocks/boulders are in the soil will determine how you prepare your planting beds. Large areas will best be prepared using a tractor that will drag the subsurface rocks across the bed and place them to one side. For smaller beds, or areas where a tractor is not possible, you may be tempted to use a tiller. Be sure to use protective eye goggles - pebbles and small rocks will bounce up from the ground! This type of ground is also very hard on a tiller, so pick a good quality one and take your time. Large rocks may still be under the surface waiting for the tiller to bounce off them.
Remove as many smaller rocks and pebbles as you can and amend the surface with peat moss/compost or other locally available materials. Use the pebbles for decoration in the garden or to surround the beds. Pebbles around a small raised bed will help heat the soil in the early part of the year and help maintain some heat in the cool spring nights, as well as aid in retaining the soil itself.
Very shallow soil may be best avoided by using raised beds. These create a sufficient growing depth that you need to maintain healthy plants.
Each year check the soil depth and runoff patterns created by spring storms. These areas may need to be built up again each year to maintain a healthy growing environment for your plants. Hill or mountain sides are particularly prone to runoff problems.Ground covers and plantings to stabilize the slope will help.
Be aware of the temperature differences on slopes or at the top of mountains. Your local recording station will likely be in a town where the buildings increase the temperatures. Check you own temperatures and compare them to the stated temperature so that you can convert quickly particularly when frosts are likely.
Gardening in rocky soils is tough but rewarding. The added advantage of spectacular views will often make the effort worthwhile. So if your American garden is sat atop a mountain - prepare well and enjoy the view!
©Text and photograph by Kate Copsey, April, 2006. Reproduction without permission prohibited.