How do I stop this mossy plant invading patio cracks and beds?

mArgAret AlliSon, by emAil

APearlwort (Sagina procumbens) is happy to colonise gaps in paving. Seeds are produced by its tiny green flowers. It’s not a moss, so mosskiller won’t control it – instead you’ll need to hoe it out of your borders and fill paving gaps with lawn sand.