Daylily Root Rot

Daylily Root Rots

Daylilies are flowering perennials consisting of approximately 15 species. These plants, with the botanical name Hemerocallis, are native to Asian and Eastern Asian countries, including Korea, Japan and China. They have long-stalked clusters of bell-shaped flowers in varying shades of yellow and red. Like most plants, daylilies are susceptible to root rot if left to stand in soggy soil, and this can kill your plants if you do not identify and address the problem in time. Read on to learn about the signs of root rot, and how to remedy this problem. 

Daylily root rot: Symptoms 

One of the most common symptoms of root rot in daylilies is the change in the color of their leaves, from green to yellow. This affects the whole leaf, from the bottom to the tip. There are no spots or streaks on the leaves, and the discoloration can spread to affect almost all the foliage on the plant. 

Other root rot symptoms include the following:

  • A gradual decline in the plant’s health
  • Stunted growth 
  • Small, pale leaves 
  • Branch dieback
  • The appearance of cankers or sunken, dead areas 

Causes of daylily root rot 

Armillaria root rot fungus 

One of the causes of daylily root rot is the Armillaria root rot fungus, a soil-borne pathogen that affects woody and herbaceous plants. The symptoms are similar to those of drought stress and include poor plant growth and yellowing leaves.  

The causal organisms, or pathogens, of the Armillaria root rot disease produce gilled mushrooms during the fall, at the base of infected plants and on shallow roots. These brown mushrooms grow in clusters and have a ring around their stalks. 

Sclerotium fungus 

Another cause of daylily root rot is a fungus called Sclerotium. Symptoms of a Sclerotium infection include the presence of cottony growth over the affected areas, and a darkened, rotting stem. This fungus can lie dormant in the soil for long periods, so if you have infected plants they should be transplanted to fresh, healthy soil, and all of the affected soil removed and discarded. 

How to fix daylily root rot

1. Check the plants.

If your plants have drooping, yellow leaves and you suspect root rot, you will need to check the whole plant thoroughly. You can diagnose this disease by removing the plants from their pots and inspecting the roots. If the roots are wet, brown and mushy, they are rotting and you need to take immediate action. 

2. Clean the roots. 

Remove as much soil as possible, as gently as you can, and cut away the affected roots with sterile scissors or shears. Gently wash the remaining healthy roots, making sure there is no infected soil remaining on them. 

3. Repot the plants. 

Once you have removed the affected roots, repot the plants using fresh soil in a new pot with proper drainage. If you would rather re-use the same pot, make sure you clean it well. Prune the tops of the plants so that there are fewer leaves for the remaining roots to support.

4. Place the plants in a bright spot. 

Put the plants in a bright area and water only when the top layer of soil is dry. Your plants will start to anchor themselves and return to their healthy state in just a few weeks. 

How to prevent daylily root rot

To prevent daylily root rot, you need to ensure proper drainage for your plants. The pots should have drainage holes so that excess water can drain off, and you should adjust your watering schedule according to the weather and the season. Avoid sporadic watering, as this can damage your plants. If the soil and the roots do not have enough time to dry out between waterings, this could lead to root rot. 

Always check the soil before watering your plants and do not water unless the top two inches of soil are already dry. You should loosen up the soil to aerate it and allow for an even distribution of water and a good flow of oxygen. This prevents moisture buildup around the roots. 

Conclusion 

Daylilies are perennial flowering plants native to Asian and East Asian countries including Japan, Korea and China. When left to stand in wet soil, these flowering plants can be susceptible to root rot, which is commonly caused by fungi such as Armillaria and Sclerotium. The common signs of root rot in daylilies include discolored foliage, stunted growth, branch dieback and a gradual decline in the plant’s overall health.

Image: istockphoto.com / Oksana Akhtanina