Plant of the Month (May) : Prairie Junegrass - Koeleria macrantha

Prairie Junegrass (Koeleria macrantha) blooming in Mother Nature's Backyard

Native bunch grasses make extremely useful filler plants.  As part of a mixed grass planting, or tucked in around trees and shrubs, they add interest, texture and habitat value to the garden.  One of our favorites, Koeleria macrantha, is blooming in the garden right now.

Prairie Junegrass grows in many areas of the United States from California to the east coast.   Locally, it can still be seen in the Santa Monica and San Gabriel Mountains.  It was once a component of the lowland coastal prairies of western Los Angeles County and almost certainly once grew in Gardena, California, where Mother Nature’s Backyard is located.

Junegrass is a perennial bunchgrass of moderate size.  It has narrow leaves (blades) that form a mound 12-18 inches (30-45 cm.) tall and wide.   Junegrass doesn’t form a spreading sod; it’s a bunch grass, retaining its clumping form throughout life.  It has fibrous roots that reach a depth of 1-3 feet (to about 75 cm).  While other native grasses have deeper roots, these are plenty deep to give Junegrass a water-wise edge over typical lawn grasses (which have roots only 6-8 inches deep).  The roots also make Junegrass useful for holding soil on slopes.

 

Prairie Junegrass is a cool season grass.  In our part of Southern California, it begins growing with the fall/winter rains and becomes entirely dormant in the hot summer/fall months.  True to its name, Junegrass blooms in late spring, usually between April and June in our area.   The flowering stalk, which rises 12-18 inches above the leaves, begins as a narrow spike and gradually unfolds into a loose plume of flowers (see above).   The flowers turn from purple-pink to gold over the course of several weeks.  Once the flowers are pollinated (they are wind-pollinated) the flowering stalk ‘closes’ again.

Junegrass is fairly easy to grow.  Plants are sometimes available from native plant nurseries (see the ‘Plant and Seed Sources’ page) but often you’ll need to start the plants from seed.  Seeds can be directly sown into the garden but we suggest starting plants in recycled nursery pots (4 inch size works well).   Seeds are best sown in winter in mild-winter Southern California (fall or spring in colder areas).

If you plant from seed, be sure to order from a company that stocks locally-adapted seeds; this plant has a wide geographic distribution and local seeds will be better adapted to your local conditions.  Use a small pinch of seeds in each pot, cover lightly and keep well-watered.   Giving the seeds several weeks of cold-moist treatment before sowing may increase germination rates.  Just place a moistened coffee filter containing the seeds in a plastic bag in the refrigerator. 

 

Junegrass likes a well-drained soil.  If your soil is very slow to drain you might want to consider another species.   We grow it in our clay-loam soil with no problem.  In hot dry areas Junegrass prefers afternoon shade or dappled shade.   In many areas, this grass grows in full sun, but in fact it takes more shade than most people appreciate.  The picture above shows Junegrass growing beneath an orange tree in a local backyard. 

Junegrass needs adequate soil moisture during its growing season; supplement the rains if needed in a dry year.   After flowering, Junegrass normally dries out in our area.  In fact, it is quite drought-tolerant but you can probably keep it green into the summer with occasional irrigation.  In our experience, Junegrass is pest-free and requires little care except for normal weeding around it.  It may reseed if it likes your garden.

In the wild, Prairie Junegrass grows with other grasses, wildflowers and shrubs in mixed prairies and meadows.  You almost never see it growing as a single-species stand.   It looks lovely when combined with other native bunchgrasses in the garden.  In our area, Junegrass, Coastal California Poppies and Purple Clarkia make an enchanting combination.   Junegrass works well as a filler around water-wise native perennials and shrubs.   Its texture adds a nice complexity to the landscape.  Junegrass looks particularly lovely with the sun streaming through it (see below).

 

Like many native grasses, Prairie Junegrass has several practical uses.  Native Peoples formerly ate the seeds – usually ground as flour – although they are small.  Grass blades were tied together and used as scouring brushes, paintbrushes and brooms.  In our area, native grasses have been mixed with clay to give strength to adobe bricks.     Like all grasses, Junegrass provides larval food for Skipper butterflies.   If deer, elk or rabbits visit your garden they’ll be sure to browse – but not kill - the tasty Junegrass.

 

For a gardening information sheet on June Grass see: http://www.nbs.csudh.edu/biology/projectsound/native_plants/pdf/Koeleria_macrantha.pdf   

 

Please feel free to comment on your experiences with this plant (below), or e-mail your questions to: mothernaturesbackyard10@gmail.com