I had a problem with rust on my hollyhocks last year, and I already see some spots on the new leaves this spring. What's the best way to combat this? |
A good fall clean up routine can help with this problem, but hollyhocks and rust are a frequent pair. An all-purpose neem-based repellent, such as Neem-Away (sold by Gardens Alive, 5100 Schenley Rd., Lawrenceburg IN 47025; 812/537-8650) may help to control it. Rust is a fungus and is ever-present in the environment, just waiting for warm, humid conditions to favor its growth. The best deterrent is to grow your hollyhocks in a sunny place with good air circulation to help the leaf surfaces dry quickly and discourage the sprouting of spores. Also, avoid overhead watering, especially in the evening. Remove any leaves that have the slivery-gray or orange growth on the undersides promptly. If it looks like you'll be in an on-going battle with this problem, you might try using Gardens Alive's Soap Shield to try to prevent future outbreaks. |