I have just put out another 3 Stinging Nettles in pots into my tarmac front garden. A moth caterpillar was already on the Nettles. It is not just about nectar I planted Broad-leaved Dock in my back garden as so many common moth species have caterpillars which eat plants like Nettles, Docks and Cleavers. We have had the Caterpillar of the Elephant Hawk Moth on the Greater Willowherb in the back garden. Also growing grasses in pots is a useful activity. I am growing Barren Brome, Yorkshire Fog, Rough Meadow Grass, ****'s-foot Grass, Common Bent Grass, Crested Dog's -tail Grass and now Purple Moor Grass in pots on the tarmac front garden and we now have Field Grasshopper in the front garden. Also growing native trees in pots also attracts herbivores.