|I have a bed of Amaryllis that have started to get rusty looking spots on the foliage. What is it and what do I do to get rid if it..
|There are many rust fungal diseases. A common way to prevent the disease from spreading is to cut back infected foliage as soon as it is noticed. During the growing season you can remove and destroy infected leaves. Disinfect tools before working between plants so you don't spread the disease further. Disturbing plants while the leaves are wet spreads the disease, so allow plants to dry before working around them. Other cultural practices include growing them in full sun, in rich moist soil and making sure they have good air circulation. Also, allow adequate spacing between the plants, minimizing overhead watering especially at night, and doing anything you can to increase the air circulation should all help. A top dressing of compost may also help the plants maintain better vigor and be more able to ward off and recover from the disease. Since bulbs need foliage to store nutrients for future growth, it's difficult to cut it all back if the rust gets too bad. Many fungicides have also been recommended to control rust. Before spraying, I suggest you take a leaf showing the symptoms to your Michigan State University County Extension Office for them to diagnose. With a more specific diagnosis they can recommend an appropriate control option. Good luck!