Mondo grass, also known as Ophiopogon japonicus, is a popular ornamental grass loved for its striking foliage. With proper planting and care, mondo grass can make a beautiful, easy-care addition to any yard or garden. Here’s a comprehensive guide on how to successfully plant, grow, and care for mondo grass in your own yard.
Selecting the Right Location
Choosing the optimal spot to plant mondo grass is key to its success. Here are some tips on selecting the best site:
Consider sunlight exposure
Mondo grass thrives in partial sun to full shade exposure. Areas that receive morning sun and afternoon shade are ideal. Too much direct sunlight can burn the foliage.
Assess the soil
Mondo grass prefers slightly acidic, rich, and well-draining soil. Clay soils often need amendments to improve drainage before planting.
Account for mature size
Allow enough space for mondo grass to reach its mature width of 12-18 inches without overcrowding. Plan for 6-12 inches between planting holes.
Pick a suitable hardiness zone
Mondo grass is winter hardy in USDA zones 7-11. It can survive light freezes but cannot tolerate extreme cold.
Preparing the Soil
Proper soil preparation helps mondo grass establish deep roots and access the moisture and nutrients it needs.
Choose your amendment
Mix in 2-4 inches of compost or well-rotted manure to improve moisture retention and nutrient content.
Aerate compacted soils
Use a garden fork to loosen heavily compacted soils before planting to improve drainage.
Do a soil test
Testing your soil pH and macro- and micronutrients can reveal amendments needed for optimal growth.
Adjust the pH
Lower pH with sulfur for acidic soils. Raise pH with limestone to hit the ideal range of 5.5-6.5.
Improve drainage
Incorporate organic material or create raised beds for excessively soggy soils. Mondo grass hates wet feet.
Obtaining Plant Material
You can start mondo grass from seed, sod, plugs or potted plants. Each has pros and cons:
Seed
Hard to find. Slow to germinate and establish. Direct sow outdoors.
Sod plugs
Offer instant coverage. Can be expensive for larger areas. Plant 12 inches apart.
Potted plants
Easy to install. Limit root disturbance. Acclimate before planting.
Divide existing plants
Free. But can take years to reach desired size. Require patience.
Buy from nurseries
Guaranteed healthy plants. Increased selection. Buy as early as possible.
When to Plant
Timing is key for successful mondo grass planting:
Spring
Ideal in zones 7-9 once soil reaches 50°F. Avoid late frosts.
Summer
Plant in zones 7-11 after extreme heat has passed. Water diligently.
Fall
Preferred planting time in zones 7-10. Cooler weather prevents shock.
Winter
Don’t plant in colder zones until spring thaw. Containerize plants until then.
Avoid transplanting mid-summer during the heat of July-August.
How to Plant Mondo Grass
Follow these simple steps for properly planting mondo grass:
Dig holes to depth of root ball
Space holes 12 inches apart. Loosened soil improves establishment.
Gently remove from containers
Handle carefully to keep root ball intact. Tease circling roots before planting.
Set crowns at soil level
Plant crowns level with surrounding soil. Burying crowns leads to rot.
Backfill holes
Fill holes with native soil, pressing firmly around roots to remove air pockets.
Water thoroughly after planting
Water deeply to saturate root zone. Avoid light, frequent watering.
Add mulch
Apply 1-2 inch layer of organic mulch like wood chips to retain moisture. Keep mulch away from crowns.
Divide clumps every 2-3 years
Thick clumps can be divided in spring. Replant 12 inches apart.
Watering Mondo Grass
Consistent water is key for mondo grass health:
Water deeply 2-3 times per week
Soak soil to 6 inch depth. Short, frequent watering encourages shallow roots.
Increase water in extreme heat
Water more often if temperatures exceed 85°F. Mulch conserves moisture.
Avoid overwatering
Saturated soils cause root rot. Allow soil to partly dry between waterings.
Do not rely on rain
Supplement natural rainfall with manual watering when less than 1 inch per week.
Water early morning
Avoid watering at night. Foliage remains wet, increasing disease risk.
Install irrigation
In-ground or drip irrigation provides consistent moisture with little effort.
Drooping foliage signals under watering
Resume regular watering schedule to revive mondo grass from wilt.
Fertilizing Mondo Grass
Proper fertilization keeps mondo grass green and growing.
Use balanced fertilizer in spring
Apply recommended rate of 10-10-10 fertilizer or similar in early spring.
Top dress annually with compost
Scatter 1 inch of compost across bed in early spring to enrich soil.
Avoid high nitrogen formulas
Excess nitrogen causes excessive foliage growth at the expense of plant health.
Watch for nutrient deficiencies
Yellowing leaves indicate nitrogen deficiency. Treat with balanced fertilizer.
Use slow release formulas
Timed-release fertilizers provide a slow, steady nutrient supply with less risk of burn.
Do not fertilize after September
Late fertilization triggers growth vulnerable to winter damage.
Every 2-3 years have soil tested
Testing reveals specific nutrient deficiencies to amend.
Pruning Mondo Grass
Pruning mondo grass helps the plant stay healthy and tidy:
Remove flower stalks
Cut off unsightly flower stalks as they appear to maintain foliage focus.
Trim foliage before new growth
In early spring, cut all foliage back near the ground to remove dead leaves.
Divide dense clumps every 2-3 years
Thick clumps can be divided and replanted in early spring.
Cut away damaged foliage as needed
Remove any leaves burnt by sun or damaged by pests or disease.
Disinfect tools between plants
Clean tools with a disinfectant like isopropyl alcohol to prevent disease spread.
Do not prune in fall
Pruning stimulates new growth that is vulnerable to winter dieback.
Remove foliage before first frost
Cut back foliage before first freeze so crowns avoid damage.
Overwintering Mondo Grass
Take steps to protect mondo grass from harsh winter conditions:
Add extra mulch in late fall
Apply 2-4 inches of shredded bark, leaf litter or other organic mulch over crowns.
Cover with row cover or burlap
Blanket plants with fabric row covers or burlap to shield from wind and cold.
Avoid early spring pruning
Leave protective foliage until the last frost has passed. Do not prune too early.
Keep soil moist if thawing occurs
Water if soil begins to thaw mid-winter to avoid desiccation damage.
Protect from freeze-thaw cycles
Consistent cold is less damaging than repeated freezing and thawing.
Cut back any winter dieback in spring
In spring, remove any foliage damaged by winter cold before new growth emerges.
Troubleshooting Common Mondo Grass Problems
Even when provided with proper care, mondo grass can sometimes struggle with issues like:
Browning foliage
This often indicates too much sunlight. Move to a shadier spot.
Rotting crowns
Improve drainage and avoid overwatering to prevent crown and root rot.
Leaf spot
Apply appropriate fungicide and remove affected foliage to treat fungal leaf spot diseases.
Declining growth
Can signal overcrowding, nutrient deficiency, or other improper growing conditions.
Weeds
Hand pull weeds around mondo grass to avoid competition. Mulch to suppress weeds.
Pest damage
Insects like grasshoppers may chew foliage. Apply insecticidal soap.
Pet damage
Dogs and cats may dig or eliminate in mondo grass. Use fencing to protect.
Dieback
Overwatering, drought, or extreme cold can cause stem and crown dieback. Improve conditions.
FAQs About Growing Mondo Grass
What are the different varieties of mondo grass?
Some popular mondo grass varieties include:
- Black mondo – deep purple-black foliage
- White rim – leaves edged in white
- Silver mondo – silver and green striped leaves
- Dwarf mondo – compact 6-8 inch height
How fast does mondo grass grow?
Mondo grass grows at a rate of less than 12 inches per year. It can take 2-4 years to fully establish and reach its maximum size. Patience is required.
Does mondo grass spread?
Mondo grass spreads slowly via underground rhizomes and division. It does not self-sow and is non-invasive. Give it space to expand into.
Is mondo grass deer resistant?
Mondo grass is somewhat deer resistant thanks to its tough foliage and low palatability. But deer may sample it. Use fencing for maximum protection.
Is mondo grass toxic to dogs?
No, mondo grass is non-toxic for dogs and pets if ingested. But it can cause minor stomach upset. Best to keep pets away from the planting.
How do you revive dying mondo grass?
Revive by clearing dead foliage, improving drainage, watering deeply but infrequently, moving to shade, and fertilizing with a balanced plant food.
Achieving Lush, Healthy Mondo Grass
With the proper planting site, soil preparation, and attentive care, mondo grass can thrive as an easy-care, ornamental grass in yards and gardens across many climate zones. Pay close attention to irrigation, drainage, light levels, and soil fertility when growing mondo grass. Maintain good cultural practices by dividing clumps, pruning away old foliage, and protecting from winter damage. Address issues quickly, whether disease, pests or environmental stresses. Do this, and your mondo grass will reward you with a lush, cohesive carpet of graceful, deep green blades.
Conclusion
Mondo grass is a superb ornamental grass for adding fine texture and appealing foliage to shady garden beds, borders, and landscapes. By selecting an appropriate growing site, amending the soil, planting properly at the right time of year, and providing ongoing care including pruning, fertilization, and irrigation, mondo grass can thrive with minimal maintenance required. Pay close attention to the plant’s soil moisture, fertility, sunlight, and drainage needs. With some patience and attentive care, mondo grass will establish well and provide many years of tranquil green beauty.