An Idiosyncratic Guide to Ornamental Grasses
Though I call this guide “idiosyncratic,” I do not apologize for that fact.
Rather, I celebrate it.
The advice and learning I share here in the Black Barn Garden Club is always filtered through the experience of my own garden, but that isn’t a limitation. Rather, it is the way of things.
Plants don’t exist in a vacuum. They don’t live in books. They live in particular places and are formed by particular conditions of soil and climate and care.
Our experiences with the same plants will never be the same, but that is part of what makes gardening so special. When you care for a patch of earth or even just a pot of it, you are creating something utterly unique.
I hope my reflections on ornamental grasses, filtered through my personal experiences with them here at Maplehurst, inspire your own garden dreams!
Why plant ornamental grasses?
When I first began gardening, I thought grasses were boring. I only had eyes for romantic flowers and delicious, heirloom vegetables.
Perhaps because I grew up in the grassy plains of central Texas, I didn’t see anything especially garden-worthy about a grass. Grass, for me, was what you dug out in order to plant roses.
Fast-forward decades, and I have become an enormous fan of these beautiful plants. Here are a few reasons why:
- Once established, many grasses are highly drought tolerant
- Grasses bring beautiful movement to a garden, especially when they flower in the fall; unlike stiff shrubs, they seem to float and dance in the slightest breeze
- Grasses are absolutely essential for creating a garden style inspired by meadows and prairies; “naturalistic” gardens are very stylish right now, and grasses are essential for that natural look
- Grasses can provide interesting structure and visual interest even in winter if their dried stems and seeds are left in place till spring
- They are absolutely glorious when backlit by the sun and provide a new way to play with light in our gardens
- Grasses are very easy to grow in most gardens and need very little care
Which grasses should I plant?
There are so many varieties to choose from and their ideal growing conditions can vary so much, that it is well worth doing at least a little research before you plant a grass.
Some ornamental grasses are perennial and some are annuals.
Some need slightly dry soil, and some soak up moisture.
Some form neat “clumps,” and some spread like a mat.
Some can handle the intense winter cold of the upper midwestern prairies in the U.S., and some will only return next year if they are growing in a warm zone 9 or 10. Some grow fastest in cool weather, some only get going when it’s hot out (known as “cool season” versus “warm season” grasses).
Some can be invasive in California or Arizona but very polite and modest in Pennsylvania (Mexican Feathergrass, I’m looking at you!).
Here are some popular varieties to consider:
Prairie dropseed (Sporobolus heterolepis): I grow this beautiful prairie grass here at Maplehurst (see how its flowers catch the light in the photo above)
Pennsylvania sedge (Carex Pensylvanica): I love this U.S. native for its graceful form and ability to tolerate shade; it’s a short, clumping grass and looks wonderful as an underplanting for trees
Japanese forest grass or Hakone grass (Hakonechloa): Another graceful, low-growing grass with a beautiful wave shape; the golden variety ‘Aureola’ is especially beautiful
Maiden Grass, ‘Morning Light’ (Miscanthus sinensis ‘Morning Light’): one of the most highly regarded of the Miscanthus; this grass makes a tall and striking feature with its variegated (green and white) stems and its feathery mauve flowers in fall
Shenandoah Switchgrass (Panicum virgatum ‘Shenandoah’): a beautiful variety of this U.S. native; Shenandoah has burgundy foliage and pink flower spikes; a beautiful medium-sized grass
Hameln Dwarf Fountain Grass (Pennisetum alopecuroides): I grew this lovely little grass in containers this year. The flower plumes are very pretty.
How do I plant them and care for them?
Grasses are some of the easiest plants I grow in my garden. They are wonderful for crowding out weeds and never need to be deadheaded. Depending on the variety and how well established they are in your garden, they likely won’t need watering, either.
The only care they do need is an annual haircut. In the past, gardeners often did this in the fall to “neaten up” their gardens for winter. But I think this takes away one of their best features. Dried grasses can be beautiful in winter when the sun hits them or a frost gives them a lacy edge. I leave my grasses alone until late winter or very early spring. Then I cut them back to the ground so that fresh green shoots can grow in.
I have found that ornamental grasses do best for me when planted in spring. I think they need a full summer of spreading their roots before winter in order to survive the wet and cold.
Most ornamental grasses need as much sunshine as you can give them and prefer very well-drained soil. Most grasses don’t like to sit in heavy, wet soil.
If your grass has grown too large or is starting to thin out in the center of the clump, it probably needs dividing. Simply dig it up in spring, cut the root ball into several pieces, and re-plant each piece in a separate spot.