Chrysanthemum plants are among the easiest perennials to grow in your garden. Their bright and cheerful flowers will bloom through the first hard frost. However, mums are not immune to diseases, including collar and stem rot of chrysanthemums. Read on for information on these chrysanthemum issues as well as tips for mum rot treatment.
About Collar and Stem Rot of Chrysanthemums
Collar and stem rot of chrysanthemums are caused by several different fungi. These include Fusarium, Pythium and Rhizoctonia.
When Fusarium fungus causes the rot, the disease is also called fusarium wilt. You’ll notice that the plants wilt, as if they need water. However, water won’t help with fusarium wilt, and the plants soon turn brown and die. When Fusarium enters through the soil line, it is called chrysanthemum collar rot. It can also enter through the roots of the plant. The diseased chrysanthemum can die stem by stem or it may die all at once.
The fungi, Rhizoctonia and Pythium, also cause chrysanthemum stem rot and collar rot. Rhizoctonia usually occurs when you get hot, dry weather on the heels of very wet conditions. When it is Pythium fungus causing the collar or stem rot, it usually results from poor drainage combined with heavy irrigation or rain.
Mum Rot Treatment
The fungus causing collar and stem rot of mums spreads easily, making it harder to control. Your plants can get the fungal disease from containers, tools, or anything used to transfer soil or growing media. Note that the fungus produces spores which can live in the soil for long periods of time.
If you want to limit these fungal rots in your chrysanthemum plants, use sterilized soil in your flower beds. It also helps to make sure your cuttings don’t carry a fungus. Proper soil drainage is essential.
Is there any mum rot treatment? If you find that your plants have collar or root rot, stop irrigating them immediately and allow the soil to dry out. You can also apply appropriate fungicides, but this usually works best if applied quickly after transplant.