I planted three Lavatera assurgentiflora (Tree Mallow) on my parent's hillside earlier this year. This was a real plant trial. They were planted with a fairly wide separation: one ended up in the midst of freshly dug gopher hole tailings (hey, the soil is nice and loose), one ended up near some other native plants, and one ended up between two black acacia trees in a spot that's a bit too shady for it.
The gophers thought that I had just given them a tasty treat. The Lavatera near their holes and near the native plants were chomped: to certain death in one case and to nearly certain death in the other. The gophers even stood on hind legs to nibble the above-ground branch ends and to girdle the bark above ground. I've never seen that sort of feasting before.
The Lavatera come from one of the channel islands from seed gathered years ago.
Here's a picture of the first to go. It didn't get very large - that's about a 1.5" to 2" trunk at its maximum. The dirty part is all that is left of the roots - as you can see they have all been nibbled back and the trunk is deeply knawed. Even the lowest branch at the right has been nibbled on top.
The second Lavatera to go lasted long enough to produce some immature seed but it is completely girdled, so I don't think it will survive. I don't know if it will self-sow or not.