Go to your favorite big box home improvement store (Lowe's, Home Depot, etc.)and buy Cygon. It can be used as both a spray and as a systemic. Also, find a spray insecticide to kill grasshoppers. Follow instructions and water the plant with Cygon. It is taken up by the roots into the tissues. When the bugs eat, they die. Now, use the other spray to spray your entire yard. Spray the lawn and any shrubs with the "other" spray. It will kill grasshoppers (and mosquitoes) hiding in your lawn and shrubs. I've used Cygon successfully on perennial, tropical and althea hibiscuses.

I have tiny green worms eating my Hibiscus leaves. I used a house and garden spray and also picked off some worms. I haven't noticed the worms on my Rose of Sharon. They will eat a leaf in no time. Not bothered with grasshoppers yet.

I had the green worms too...and little white bugs and aphids...and ants...I use a tiny amount of dish soap diluted with water, pick them off, brush them off or soak the plant with a hose. However, mine is a hardy one with small red flowers and thick leaves. I wouldn't try that on a tropical...i had to move my tropical inside because of the scorching texas heat!

Dusting or spraying with Sevin is actually the most effective control for grasshoppers. It's pretty safe, as chemicals go.

I have been using Liq. Sevin also and it works well. You need to respray after each rain for best control

Thank you.I will most likely use the sevin dust as I couldn't find the cygon at lowes.We have some huge grasshoppers too.They only seem to bother the hibiscus right now.