Falling Short: Mexican Feather Grass

I was very excited to find seeds for Mexican Feather Grass, stipa tenuissima aka nassella tenuissima, earlier this spring. For the past couple of years I have noticed its lovely fine foliage in garden pictures and admired the way it gracefully arches sideways in the wind. I potted up a few milk cartons and stuck them outside with the rest of my winter sown pots. They sprouted late--possibly set back by the early April snowstorm--but I did end up with half a dozen seedlings by the end of May.


My front yard seemed the perfect place to site these seedlings. Mexican Feather Grass is supposed to be fairly drought tolerant, and my other xeriscape-friendly plants thrive there. It is a Western exposure, so I imagined they would look like long ponytails (Ponytail grass is another of its common names) whipping around in the wind, adding lots of movement.

There are quite a few thick-leaved plants there, from purple salvia lyrata to the glaucous leaves of sea kale, crambe maritima. Some grasses, including carex buchannii and 'Hameln' pennisetum, were already in residence in that bed, but I was counting on the Feather Grass to add some more fine texture. Its pre-flowering fresh green color would be a nice stepping stone between the dark greens of Spanish foxglove and the golden tones of variegated sage and the chartreuse 'Aureum' oregano.


Even though they were first-year plants, I admit that I did not water my feather grasses perhaps as much as I should have early on. In my defense, it was hard to remember to water them as they sat, small but uncomplaining, amongst the water-shunning likes of lemon thyme, lavender and sedum.

As you can see in this picture, they never did get taller, flower or fill out--nor did the silene maritima 'Compacta' that I planted in the center of them to act as something of a "ground" for the grasses. The silene was a last minute addition, so next year I'm going to try something else there instead--possibly a short salvia like 'Marcus,' a moody 'Matrona' sedum or maybe a wine-red portulaca.

As for the Mexican Feather Grass? Well, what happens to it over the winter remains to be seen. I've seen it listed as hardy to zone 5, but my seed packet more conservatively lists it at zone 7. One reviewer on the wonderful DavesGarden website is in an Ohio zone 6 like me and says that first year plants seem to come back the next year for him/her, while plants that have flowered die off over the winter. That gives me hope... but I'll wait and see.