Many of the ornamental grasses are considered to be drought tolerant. In the literal sense, these grasses can withstand periods of drought. Consider grasses that grow naturally in low areas such as roadside ditches, wet
meadows and along streams and ponds. These areas often approach flood-like conditions each spring. By mid-summer the water table has dropped and the soil dries out. Despite the change of available moisture some grasses continue through their growth cycle, while others go semi-dormant until the fall. Both responses indicate different ways of exhibiting drought tolerance.
Ornamental grasses respond to drought in similar ways: the warm season grasses generally have thicker roots as well as narrow leaves and are able to grow through the dry seasons. Many of the prairie grasses (Andropogon, Panicum, Sorghastrum, Schizachyrium) as well as Miscanthus and Pennisetum are in this category. However most of the cool season grasses will slow down and go semi-dormant in the heat of summer. Excessive water is not recommended during this period. Fescues in particular will require less dividing if watered less. The idea is to water just enough to keep the plant from turning brown. Turf grass would also be in this category.
Bluestem's drought tolerance rating is a general guide for you to keep your grasses looking their best. Available sunlight, soil texture, mulch, humidity, dew, night-time tempeatures, wind and other local factors will all have an effect of this schedule. It is important to understand that the rating is designed for full size, well-established plants. Newly planted grasses and especially grass plugs will need ample water to become firmly established.
The drought tolerance rating:
- 0= no subsequent irrigation needed
- 1= water to root depth once every month
- 2= water to root depth once every two weeks
- 3= water to root depth every week
- 4= water to root depth when soil starts to dry
These are general suggestions. Keep an eye on your plants.
Grasses are very forgiving plants, so don't hesitate to experiment by adjusting the rate according to your local conditions.