I have some questions about Delosperma cooperi, or Cooper's Hardy Ice Plant.
Last spring, we did a late planting in a part of our yard as an experiment (Zone 9, maybe 10 in southern California). It was a narrow strip between our house and the neighbor's, so it gets only a few hours of direct sunlight. In the past, we had had trouble growing anything other than weeds in that spot. With some work, I dug everything up, adding some new topsoil & fertilizer, and dug a drainage ditch. Instead of the Bermuda grass that traditionally went there, I replaced it with Delosperma cooperi plugs spaced 6 inches apart.
I did my research before I started. I knew it wasn't picture-perfect conditions for the plant, but with how hardy it is, I felt we had a chance of success. And boy, was I right! The nursery from which we bought the plant advised planting plugs with 6-inch spacing and said that it would fill in by 6 months. Instead, most of it had filled in within a month, and it was still growing aggressively. We're now looking to partly or fully replace the front lawn with it.
However, the experience did not entirely match our expectations, I want to understand this plant better before we start on the major project this fall. For one, everything I've read online was the opposite or near-opposite of how the plant behaved. I had read that it loves sun, but will slowly creep into very shady spots, despite the lack of direct sun. Instead, ours grew best in the shady spots and struggled most in direct sun. Also, after the first few months, I tried to cut back on the watering to enjoy the drought-tolerant nature of the plant, going from once every other day to once or twice a week. As a result, the fresh carpet of green began to struggle and a few dead spots appeared.
Even its growth confused me. I had always seen examples of it as very short, with tough, crowded succulent leaves clustered close to the ground. I know it spreads through runners, but those long, thick tangles of runners were all we saw. It even caused a problem because it seemed to attract either a cat or a raccoon every night, and they loved to toss tangles around or rip it up in places. I've been expecting the plant to become the thick, compacted mat of succulent leaves, but even this late in the season, it still almost entirely consists of long tangles of runners.
Lastly, what we planted doesn't seem to handle foot traffic quite as well as people have claimed online. I know it's not meant for heavy foot traffic, but in all the places I've seen it growing, the leaves were tough and firm, easily handling a person's weight as they passed over. Ours, however, has very soft, squishy leaves, which I admit may be due to the regular watering. However, when we cut back the watering, the leaves don't firm up. Instead, the plant wilts.
Otherwise, the plant has been a delight as a grass replacement. Yes, it's "invasive" (growing aggressively), but it's easily controlled--much more so than that damn weedy Bermuda grass that's not native either. Plus the HOA is likely to give us a pass since it looks like a grass lawn at a glance, versus how a natural landscape will only upset them.
I'm certain of the identity of the plant. I put a lot of effort into that, and I even posted questions on this forum in the past. I'm wondering if there are other varieties out there. I know Dwarf Carpet of Stars (Ruschia lineolata) is virtually identical, except for its seed pods. It's description and needs better match the Delosperma cooperi descriptions I had read than what I'm seeing in our yard, so I doubt it was a mix-up with that one.
Anyway, sorry for the short book. If you've made it this far and know something about the plant, I'd love to hear your thoughts.
I'd also like to know how plugs will deal with being planted in disturbed soil that's been treated with pre-emergent herbicide two weeks prior. I want to keep the weeding down this time, especially since the foot traffic can pack down the fresh soil. (Fortunately, the narrow strip and the drainage ditch down the middle helped give me a place to walk last time.)
I'll post more pictures soon. Thanks in advance!
