Ponytail grass (Stipa tenuissima) is also called Mexican feather grass. This ornamental perennial grass forms clumps 18 inches wide. Ponytail grass produces arching, needle-thin foliage 15 to 18 inches tall. These bright green hairlike blades sprout bright green seed heads. In the fall, mature seed heads turn golden and fluffy. Ponytail grass is low maintenance and blossoms the first year after planting.
Remove the weeds and debris from a planting site in full sun with well-draining soil. Ponytail grass does not survive in soggy soil. Loosen the soil to a depth of 12 inches with a shovel. Mix in 3 to 4 inches of organic material like compost.
Add 2 to 3 tbsp of slow-release 10-10-10 fertiliser to the top 6 inches of soil. Dig a hole as deep as the root ball and plant the ponytail grass clump at the same depth as it was growing in its plant pot.
Water the newly planted ponytail grass lightly each day for the first two weeks. Reduce the watering schedule over one to two months. Establish a watering schedule of once every two weeks. Do not keep the young plants wet since this will kill the grass.
Cut the ponytail grass back to 2 to 5 inches tall with a pair of hedge shears in the early spring before new growth begins. This clears away any winter-damaged foliage and makes room for the new growth.
Divide the ponytail grass clump every three years to prevent overcrowding. Dig the grass up with a shovel and cut it into three or four pieces with a sharp knife. Replant the healthiest piece in the same area and plant the other sections in a new area in the landscape.
Ponytail grass does not need frequent feeding. Only fertilise when the ponytail grass appears stunted, does not grow well and turns yellowish.
Ponytail grass becomes invasive if planted in a favourable area. Harvest the feathery seed heads before they drop the seeds to control the spread of ponytail grass.