Mexican feather grass (Nassella/Stipa tenuissima)

Q: I have a large hill in front of my house. It has some partial shade areas due to mature trees. After recent construction, the hillside is dead and needs to be replanted. I am looking for something with color that is easy to maintain. My gardener suggested a type of tall grass, but that has no ‘wow.’ What would you suggest?
Tami Younesi
Tarzana
A: The most daunting aspect of your landscaping challenge is the fact that you have a large hill. Large landscapes or gardens, be they hilly or not, require a gradual approach in their design. A garden is always a work in progress and, where large areas require plant coverage, there is good reason to achieve such progress little by little. This makes sense especially where your time and pocketbook are concerned.
Caution is particularly advisable in partial shade situations like your own. You no doubt have areas that receive more sun than others. You will have to chart the amount of sun that reaches the various sectors of your slope over four seasons and plant accordingly.
You mention that your gardener suggested you plant a tall, presumably ornamental grass. I understand that you want something with colorful eye appeal, but you may be surprised to learn that a combination of ornamental grasses and sedges can provide you with the special effects you seek. There are red, blue and golden grasses whose collective effect can be dazzling enough. There are also grasses that wave in the wind, animating your landscape the way no ordinary ground cover could ever do.
Remember that slopes are not intimate landscapes in the manner of gardens or flower beds around the house. A slope is viewed from a distance and, to be brought closer to your mind and to your heart, will be appreciated more keenly if it is inhabited with undulating grasses. Grasses also have many other appealing design attributes, such as texture, bold flower spikes and overflowing forms.  An excellent option in this regard is Mexican feather grass (Nassella/Stipa tenuissima).
An important advantage of landscaping slopes with grasses is erosion control, a necessity brought sharply into focus during the recent rainstorms. The roots of ornamental grasses do a wonderful job of holding slopes in place.
Greenlee Nursery in Pomona has a collection of more than 300 ornamental grasses. The nursery is open to the public, but by appointment only. Call (909) 629-9045, or make contact online at www.greenleenursery.com.
If you choose to go the route of planting with grasses, you can bring additional pizazz to your slope by inserting, here and there, perennial shade-loving begonias, such as ‘Dragon Wing,’ as well as coleus, which is grown for its kaleidoscopic foliage.