David, the broom is Spartium junceum. Its growth reminds me of a Palo verde tree. Lots of green stems and not much in the way of leaves, but lots of yellow blooms. I'd try and grow a Palo verde here, but it gets too cold for them. Grasshoppers have definite preferences (think any irid) and it may be just as well to know the Spanish Broom falls into that category. I was worried about its cold tolerance and never thought about it being grasshopper food when I bought it. I may pass on trying it again - unless it's on sale, then who knows?
I'll have to look up and read about Keiki paste
. I doubt it's readily available locally, so it would likely be an online purchase if I decide to try it.