Mondo grass is the kind of ornamental grass you would want to grow on your lawn or in your garden. It’s perennial and evergreen, and it does well both as a groundcover or a standalone plant.
As a slow-growing grass, it doesn’t require a lot of maintenance. It grows well even in poor soil and light conditions, but sometimes the evergreen mondo grass will turn yellow and wilt.
Why is my mondo grass turning yellow? Mondo grass will turn yellow if the soil is poorly drained or it’s getting too much direct sunlight or reflected heat. The grass might also start to wilt if it doesn’t get watered for a long time. Both root rot and crown rot can cause the grass to lose its lush green color.
It’s important that you take action when your mondo grass turns yellow; otherwise, the grass might wilt and die.
Keep reading to find out the 9 causes of mondo grass turning yellow and what you can do about them.
Yellowing Mondo Grass – 9 Causes & Solutions
Although mondo grass is a hardy plant with tolerance to different growing conditions, there comes a time when it will show signs of stress where the leaves turn yellow and start to wilt.
More often than not, the cause for the problem has to do with the growing conditions, but sometimes, the grass has a disease or a pest infection.
1. Too Much Sun
If you grow mondo grass as a groundcover, chances are you’ll find yellow spots where the grass is getting exposure to the full sun.
This would also happen if either heat or intense light reflected from a building on the grass.
Protect the grass by erecting a structure that provides partial shade. You can also plant a tree or a tall plant to cast its shadow on the bright spots.
2. Insufficient Water
Mondo grass needs about 1 inch of water every week. If you don’t have enough rainfall, you will need to irrigate the grass.
During the first year after planting mondo grass, you need to keep the soil moist regularly. Once the grass establishes, you can allow the top 1 inch of the soil to dry between irrigations.
If insufficient water causes mondo grass to turn yellow, the same could happen if you overwater it.
This plant doesn’t like to sit in waterlogged water. Poor drainage soil such as clay would cause root rot.
Check that the top of the soil is dry before you water the grass. If the soil is still moist, hold off watering.
4. Root Rot
Root rot is one of the main causes of mondo grass turning yellow. It’s caused by a fungus called Pythium splendens.
Dig up the infected plants and examine the roots. Trim off the damaged and rotted roots and replace the soil with a fresh and sterile growing medium.
You need to treat the surrounding area with a fungicide that contains Gliocladium virens.
5. Crown Rot
This is another disease caused by a fungus that thrives in waterlogged soil and warm and humid conditions. Once the fungus infects the soil, it will stay in it for years.
Treat the infected soil with a fungicide, and repeat applications until the grass recovers.
6. Poor Soil Drainage
Clay soil is known for its poor drainage. The roots of mondo grass are sensitive to excessive moisture, and when the soil doesn’t drain well, the roots will rot. This causes the grass to turn yellow.
Amend the soil with perlite or coarse sand to improve drainage.
Snails and slugs are the two most common pests that attack mondo grass and cause the most damage. As they eat through the crown, the leaves get fewer nutrients and become yellow.
Manually pick all the snails and slugs you find in the garden, and drown them in a bucket full of soapy water. Spray the infected area with iron phosphate to control the pests.
8. Extreme Temperatures
Mondo grass is hardy to cold temperatures but has less tolerance to extreme temperatures.
Try to protect the grass by planting leafy trees and shrubs to cut down the exposure to the sun. Also, watch out for reflected heat from buildings and high surfaces.
A makeshift umbrella or a canopy can keep the plant cool during the hot summer months.
9. Fertilizer Burn
The slow-growing mondo grass doesn’t need strong fertilizer. This could cause root burn.
Apply a diluted fertilizer for grass once every two weeks. Always water the grass immediately after each application to further dilute the fertilizer and prevent root burn.
Landscaping With Mondo Grass
Mondo grass is an ornamental plant that works well both as a groundcover and a standalone plant. Here are a few ideas to landscape with this grass.
- Use it for natural beauty around the patio or seating place in the garden.
- Plant mondo grass along paths to give them prominence.
- It’s ideal for adding a green touch to a modern landscape.
- Mixed with flowering plants, it gives the landscape a prairie-like appearance.
- Use it as a boundary or divide in the garden.
Is Mondo Grass Deer Resistant?
You can plant mondo grass in your garden or lawn without worrying about deer or other wildlife. The hardy grass is deer resistant since its stalks are too tough and offer little nutrients to the deer.
Can You Mow Mondo Grass?
Mondo grass is a slow-growing plant. It develops foliage that takes the shape of dense tufts. As such, it doesn’t require mowing like other types of grass in the yard.
You can prune and trim it to maintain its shape and manage its size.
If your mondo grass turns yellow, look for problems with the poor drainage soil, extreme heat or light, root rot, crown rot, or fertilizer burn.
Also, check for pests such as slugs and snails wreaking havoc with the ornamental grass. Water the plant regularly as it has a low tolerance for drought.