it does attract ants which kill caterpillars. try another senna/cassia variety for attracting sulphurs

Am familiar and have Candlestick Cassias that grow no more than ten feet and are very attractive I got seeds cheaps in eBay grow fast and host the larger and smaller yellow type BFs

I haven't have much trouble with ants, no more than in any other of my host plants. I put some blackboard chalk on the bottom of the plants. For some reason ants don't cross any chalkline I make and only harass my small caterpillars. The bigger one defend themself well.