native grasses for yard cover
We're seeking native ornamental grasses that can help us avoid mowable lawn. What can you recommend, please?
Washington County Oregon
Thanks for your question about ornamental grasses replacing sod. I'm going to answer you both from a Master Gardener perspective, as well as a gardener who has done this and learned a few things in the process. (Note: I am not a landscaper, and you can undoubtedly find resources from those who are actually trained in it.)
OSU had a great Extension agent in Yamhill County (Linda McMahan) who was passionate about native plants and, although this publication doesn't have native grasses, it does explain the theory behind using native, rather than imported, plants. (And it may give you some ideas for intermixing grasses with other types of plants.) My first go-to resource is this Metro publication, which has grasses indexed with other perennials, starting on page wt, Here, though, is a list of some popular (and available) grasses, with an explanation of their sizes and USDA hardiness zones. (You can find your zone here.) I have also found a few grasses in this Central Oregon xeriscaping (low-water) guide, on page 22 and 23. With our increasingly drier (at least in the summer) weather in the valley, these water savers do quite well. You'll find many grasses referred to in most or all of these; I apologize for the duplication.
When I began my journey, I bought "Grasses," a book by Nancy Ondra, after I took the online OSU course on Native Plants. My primary goal, other than relieving my husband from mowing, was to create a pollinator friendly and attracting garden, so I added dozens of lavender and Russian sage plants, as well as a mix of bulbs, perennial shrubs and evergreen trees. You can see views of some of the results below.
What I learned: pay attention to the size the plants get. I had to remove several Northern oat grasses because they just grew too large. I want my plants to create protection for wildlife, so I planted them close together, but in some cases, too close. I planted Greek oregano. Good idea for the bees; bad idea for a 'tidy' garden. (Although, remember that nature is a mess--which is good for wildlife!) I made the mistake of planting spreading plants too close to walk paths (although it's really not designed for humans anyway). Sedges, especially, grow really, really wide, and, because they have edges, they hurt your ankles! ("Sedges have edges, rushes are round, grasses are hollow from the tip to the ground.") Finally, I learned you need to decide when to prune the grasses--true grasses, not sedges or rushes--which develop seed heads. I choose to leave the seeds for the birds in the winter, but that means I need to get out in early (cold) spring, to remove last year's growth before the new is coming in and I'm removing greenery. And some grasses are tough and difficult to cut in any season.
I hope this is helpful to you. If you have any other questions, please don't hesitate to write back. Thanks for using Ask an Expert!