People are willing to grow all sorts of plants as containerized houseplants, with one notable exception: ornamental grasses. It is hard to understand because grasses have so many desirable qualities. They are beautiful, hardy, not too discriminating, and can be easily replaced. It’s true that ornamental grasses can be “dirty,” dropping seeds and seed pods, but if you simply snip off blooming stalks, you can deal with this issues easily.
Among the various grasses, mondo grass (Ophiopogon japonicus) is an excellent place to start with indoor grasses. It’s a low-growing grass that stays less than five inches tall and is very tough and drought tolerant. Healthy mondo grass has a deep green hue and somewhat resembles turf grass. It’s an excellent option for a decorative, contemporary container or to be used as a ground cover in a larger container.
- Light: It does best in filtered sunlight, although it can tolerate partial shade and even direct sunlight.
- Water: Mondo grass does best with regular, even water, but it is somewhat drought tolerant and can handle periods of extended dry.
- Temperature: Room temperature is good. Mondo grass is not particular in regards to the temperatures, but cannot withstand freezing.
- Soil: A regular, well-drained potting soil should be fine.
- Fertilizer: For best results, use a regular controlled-release fertilizer at the beginning and middle of the growing season.
Mondo grass is a spreading grass that can be divided into clumps to create new specimens.
It’s not particular to repotting needs, as it is a low-growing plant with a relatively shallow root system. Instead of repotting, you can simply divide the existing plant, thereby giving the potted specimen more room to fill in the container.
If you must repot, give it new soil.
The main species is the best one and should fit most uses. There is a dwarf variety, however, if you are limited in space. There is also a larger variety that grows a bit taller than the standard but is still much smaller than liriope or other ornamental grasses and grass-like plants.
Mondo grass is not difficult to grow and should be rewarding almost immediately upon planting. For best results, supply dappled sunlight, regular fertilizer, and regular but not excessive water. These plants are somewhat vulnerable to pests, including scale and mealy bugs, but it should be relatively easy to treat with a simple soap or mild insecticide. If the plant can be moved, you can also take it to a sink or outside and use a high-pressure water spray to blast the bugs off, and then switch to the least toxic pesticide to prevent their return and kill any larvae the water didn’t get. In landscapes, mondo grass is considered a good option for areas that are shadier and drier than other sub-tropical and tropical plants like, which makes it a near-ideal houseplant candidate.
Don’t be surprised if your mondo grass migrates a little bit in the container—this is a slow creeping grass that should eventually fill in the available space.
In general, this is desirable, so look for applications where a ground cover-like effect is desired. Lastly, mondo grass can be difficult to find outside of its chosen habitat in zone 8-10. If you happen to find some in your local nursery offered as an annual, pick up a few plants and space them about 8 inches apart in your growing container, then water and let the plant do the rest. If you see dry leaf tips or browning, chances are the plant is getting too much sun and not enough water or both.