In 2010/11, we planted out the first living roof on a home in Wellington. It’s been just fine.
The initial plants were a mix of succulents, seddums, and native ground cover. The roof has enough variation of sun, wind, and shade that some did well in areas, some in others, and nothing died out. Since then, koromiko has self-seeded and grown up, just as it does all over Wellington. It’s growing so well that we’re trying some other, lower-growing hebes.
A few other native trees have found their way up there on their own, like taupata . We were originally told that the soil depth of only 100 mm was too shallow for tussock, but last winter we planted carex secta, flagellifera, and comans green and that’s doing just fine. There’ll be more this winter, though not the secta as that’s too sharp to weed around.
Maintenance has been weeding and the only real problem plant has been oxalis. The birds ignored the roof for a few years, but have started to tear the soil up to get at ants. We’re just planting hebe and tussock as that’s too large for the birds to damage and they give more variety to the height of the planting. The koromiko needs pruning at knee height – the thin soil means if they get too big they will fall over. And the random lancewood will need to be transplanted off the roof, coz that can grow to fifteen metres tall.