We're in a hot, dry climate (Denver, CO) and we have inherited a large swath of gravel landscaping. It is pretty boring, just one kind of red rock. It is also showing its age. The underlying plastic has got punctured here and there, and in some spots has bubbled up to the surface. Organic matter has accumulated within the gravel, and supports the growth of weeds. The weeds are usually pretty easy to pull, but it is time-consuming and boring. It is right along the street, and faces south and west; it is the first area where snow melts in the yard.
For many years, I've planned to remove the plastic, move the gravel into more aesthetically appealing, smaller swatches, and create a cactus garden. However, as anyone who has ever done this knows, moving gravel is backbreaking work. Also, I removed one small patch only to have perennial weeds take over the uncovered soil.
I've recently realized, however, that this mix of a few inches of gravel and organic matter over a plastic membrane is very much like a green roof, just sitting on the ground. If I planted sedums, ice plant, prickly pears, and similar plants, would they do as well as they do on a green roof? I've actually noticed that some annuals like growing in gravel; it allows rainfall to quickly infiltrate and keeps evaporation down. A friend of mine gets a crop of cosmos in his unwatered gravel every year. And the weeds certainly seem to like growing in the gravel, much to my dismay.
I might enlarge some of the existing holes and use them as planting spots for deeper-rooted plants.
Has anyone done anything like this or have any other ideas?