The downside is that when you grow grasses in containers, they are less hardy—generally by about two hardiness zones. For example, an ornamental grass rated for USDA hardiness zone 5 when planted in the ground typically is hardy only to zone 7 when planted in a pot. (Note: the USDA zones listed below refer to ground-grown plants, not container-grown.) The actual hardiness of a container-grown ornamental grass depends upon its exposure, the material of the container, weather fluctuations during the winter months, and how well you winterize it. However, you can always treat ornamental grasses in containers as annuals, replanting them each year. Or, if you have space in a sheltered spot, like a greenhouse, garage, or basement, simply place the containers inside to overwinter. Here are 10 good choices for ornamental grasses to grow in containers.
USDA Growing Zones: 3 to 9Color Varieties: Blue-green foliageSun Exposure: Full sun to part shadeSoil Needs: Average dry to wet soil
USDA Growing Zones: 4 to 8Color Varieties: Steel-blue foliageSun Exposure: Full sunSoil Needs: Dry to medium moisture, well-drained soil
Other varieties to try include Pennisetum ‘Burgundy Giant’ and Pennisetum orientale.
USDA Growing Zone: 9 to 11Color Varieties: Red/purple foliage (other cultivars are shades of green)Sun Exposure: Full sunSoil Needs: Medium-moisture, well-drained soil
USDA Growing Zone: 5 to 9Color Varieties: Yellow-green foliageSun Exposure: Part shadeSoil Needs: Moist, well-drained soil
USDA Growing Zone: 8 to 11; grown as an annual in cooler climatesColor Varieties: Light green foliageSun Exposure: Full sunSoil Needs: Dry to medium moisture, well-drained soil; tolerates dry conditions
USDA Growing Zone: 5 to 9Color Varieties: Medium-green foliage with brownish flower/seed stemsSun Exposure: Full sunSoil Needs: Medium-moisture to wet soil; tolerates clay soil
USDA Growing Zone: 6 to 9Color Varieties: Bronze to brown foliageSun Exposure: Full sun to part shadeSoil Needs: Rich, moist, well-drained soil
USDA Growing Zone: 5 to 9Color Varieties: Silver-green or variegated foliageSun Exposure: Full sunSoil Needs: Medium-moisture, well-drained soil
USDA Growing Zone: 10 to 11Color Varieties: Gold-green foliageSun Exposure: Full sun to full shadeSoil Needs: Medium-moisture to wet soil
USDA Growing Zone: 9 to 11Color Varieties: Bright green or striped/variegated foliage (depending on cultivar)Sun Exposure: Full sun to part shadeSoil Needs: Medium-moisture, well-drained soil
Instead, ornamental grasses do best when planted in a mixture of compost, topsoil, and a small amount of grit (such as fine gravel or perlite). Species of grasses that prefer medium-moisture or wet soil require more frequent watering than those that prefer dryer soils but don’t attempt to alter the quality of the soil to match the type of grass.