Posted by Brent Wilson on 7/13/2016 to Planting & Growing Tips
Mondo Grasses, Ophiopogon, are some of the easiest plants to grow when planted right and in the right spot. They are ideal for use in the landscape massed as groundcover or as a gap and crevice filler between stepping stones, pavers and boulders. The dearf mondo grasses provide a very attractive soil cover in container gardens while tall mondo grass provides a vertical accent and grassy texture.
Here's a breakdown of what you need to know regarding planting Mondo Grass in the landscape or in pots...
Mondo Grass tolerates a wide range of soils and soil conditions, except for constantly soggy or wet soils. When growing in a container use a good potting soil, potting mix, or combination of thereof.
Testing Soil Drainage. If you are uncertain about soil drainage in the area you intend to plant your Mondo Grass, it's well worth taking the time to test the drainage before planting. To test soil drainage, dig a hole 12" wide by 12" deep. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in loose, sandy soil, may signal potentially dry site conditions and possibly a need to add organic matter to help retain moisture. A slower rate indicates poor draining soil and is a caution you need to improve drainage, plant in a raised mound or bed, or look for plants that are more tolerant of wet or boggy conditions.
Modo Grass grows best in a moderately to slightly acid soil ranging from 5.0 to 6.5 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
Testing Soil pH Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline. If you're unsure about the pH of your soil, and whether or not it's suitable for growing Mondo Grass, it's a good idea to test the soil pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe. To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil Sulfur, Aluminum Sulfate, or Chelated Iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.
Learn More: What is Soil pH and How To Adjust It?
Most Mondo Grass will grow in part shade to shade. Some varieties will tolerate more sun. Know the sun preferences for the specific variety of Mondo you intend to plant.
Note: On every plant page in Wilson Bros Gardens you will find the sun preferences under the Description tab in the Plant Details section.
(Scroll down to see planting instructions for containers and pots)
Site Preparation When Massing Mondo Grass As Groundcover
Before planting, eliminate existing weeds or grasses in the planting area. You can pull weeds by hand or spray them with a solution of glyphosate-based broad spectrum weed killer. Wait at least two hours after spraying a glyphosate-based product before you begin planting. Before using any chemical read the mixing and application instructions on the label.
Tilling the soil in the planting area is optional. There are several reason we usually don't recommend it. Tilling on sloped ground loosens soil making it more susceptible to erosion in the event there comes heavy rainfall. Tilling can also bring buried dormant weeds seeds to the surface. Freshly tilled ground is a perfect environment for weed seeds to sprout in. If you do decide to till, we recommend the application of a landscape landscape weed preventer to the soil surface. Also, if you are planting groundcover plants under established trees, be aware that tilling can cause serious damage to tree roots, which can effect the health of a tree. The feeder roots of trees can often extend well beyond the perimeter of the canopy.
How Many Plants To Fill A Space?
If you are planting your Mondo grass as a groundcover over a large area, to determine how many plants you will need, it is often necessary to determine total square feet of the planting area. Once you have the square footage, then you can determine how far apart you will space plants in the planting area. (Under the description tab on every plant page in Wilson Bros Gardens you will find a spacing recommendation.) Click on the links below to get helpful tips.
Step-By-Step Planting Instructions
Set and space all plants out in the planting area before starting to plant. Alternatively, you can use marking paint to mark the spot where each plant will go, which is often necessary when planting on steep slopes, where plants in containers will not stay put.
If there will be more than one row of plants, begin by setting out or marking one straight row of plants. It's best to start along the edge of the planting bed making sure to space plants at a distance far enough from the edge of the planting bed to allow for future spreading. For example, plants with a recommended spacing of 24" apart should be spaced at least 12" from the edge of the bed (or surfaced area) to the center of the plant. After setting out the first row, stagger the plants on the second row and so on until the space is filled.
Depending on the type, fertility and porosity of the soil in the planting area, it may be beneficial to amend the native soil. When planting in heavy clay or poor soils mix in organic matter such as composted manure or a good planting mix at a 50/50 ratio with the soil. When planting in a sandy, quick-draining soil amending with top soil, organic compost, or peat moss will help to retain moisture and supply vital plant nutrients. When planting in a fertile, loamy, well-drained moist soil there is no need to amend soil.
To remove your plant from the container it was growing in, firmly grasp the base of the plant and gently lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and gently pound on the side of the container to loosen the root ball. After having removed the plant from the container, gently loosen some feeder roots around the surface of the root ball. If root bound, you can gently spray the sides and bottom of the root ball with a stream of water from a garden hose. This will help to wash away some soil from the exterior of the root ball making it easier to loosen roots.
Set your plant in the planting hole so that the top edge of the rootball is at or slightly above ground level to allow for settling. It may be necessary to place some of your backfill soil mixture in the bottom of the hole to achieve proper planting height.
After setting your plant in the planting hole , use one hand to hold the plant straight while using your other hand to begin backfilling the soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue backfilling to the top edge of the root ball. To avoid suffocating your plant, do not put any soil on top of the root ball.
After planting some or all all of your plants, deeply water the entire planting area. For an extra boost, you can also water with a solution of Root Stimulator, which stimulates early root formation and stronger root development. Root Stimulator reduces plant shock and promotes greener, more vigorous plants.
Apply a 1" layer of aged, shredded wood mulch or bark or a 1-2" layer of pine straw around your newly planted plants. Do not use freshly chipped or shredded wood for mulch until it has cured in a pile for at least 6 months, a year is better.
Container Planting Instructions
Mondo Grass are ideal for adding a grassy texture or soil cover to mixed container garden plantings.
When growing in pots Mondo Grass appreciates a moist but well-drained soil. Constantly soggy soil can and often will cause root rot or other harmful or deadly plant diseases. Therefore, plant in a container or pot that has a drainage hole(s) use a quality potting soil or potting mix, or a 50/50 combination thereof for planting.
Make sure to choose a container that is large enough to allow for 2 to 3 years of growth before shifting up to a larger size container. This might mean your planting pot would be 4 inches or more in width than the root ball of your plant.
Container color will matter as well. Not only will you want to pick a color of container that goes well with the foliage color of your Mondo Grass, you'll also want to pick a container that matches the style of your home or other structures and other plants in the surrounding environment.
Many nursery & garden centers offer a wide variety of containers to choose from. Before heading out to buy a container take pictures of your home and the surrounding environment. Doing so will help you to choose just the right color and style.
Before filling your container with the soil mix, we recommend lining the bottom with shade cloth or a porous landscape fabric. This will keep the drain holes from becoming stopped up with soil.
To remove your Mondo Grass from the container it was growing in, firmly grasp the base of the plant and gently try to lift and remove it from its container. If the root ball is stuck in the container either cut the container away or place the plant on it's side and gently pound on the side of the container to loosen the root ball. After having removed the plant from the container, gently loosen some feeder roots around the surface of the root ball.
Pour a small amount of your soil mixture in the bottom of the container. Set your plant in the container and make necessary adjustments by adding or removing some soil so that the top edge of the root ball will sit 1/2 to 1" below the rim of the container.
Backfill with your potting soil around root ball, tamping as you go, until the level of potting soil is even with the top edge of root ball.
Water thoroughly until water starts to drain from the holes in the bottom of the container. Add more potting mix if settling occurs during watering.
Step 6 (Optional)
Apply a 1/2" layer of wood chips or sphagnum moss to soil surface to help conserve moisture.
Related Articles from Our Experts
Questions? Contact Us!