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Monday, October 13, 2014

Plant of the Month (October) : Torrey’s rush – Juncus torreyi

Torrey's rush - Juncus torreyi


October is the heart of the dormant season in Mother Nature’s Backyard.  This is a pleasant time of year, but not a lot is blooming.  If you didn’t catch our posting on ‘The Year in a S. California Garden’ (Sept/2014) you might enjoy reading it.  One of our showiest plants right now is, surprisingly, a rush.  Of all the grass-like plants, Torrey’s rush is clearly the diva this time of year.

Torrey’s rush (Juncus torreyi) honors Dr. John Torrey (1796-1873), American botanist and co-author (with Asa Gray) of The Flora of North America.  It grows wild in most of temperate North America, from southern Canada to northern Mexico.  In Los Angeles County, Torrey’s rush can be found in the San Gabriel, Santa Susanna and Liebre mountains; it once also grew along the L.A. River.  Not surprisingly given its wide geographic distribution, the physical (phenotypic) characteristics of Torrey’s rush vary somewhat across N. America.

Torrey’s rush is a good example of a rush.  Most people have heard of rushes.  They grow in/near wetlands in most parts of the world and are often used in basketry and other local crafts.  But many people don’t know exactly what a rush is and how it differs from other grass-like plants. 

Rushes (family Juncaceae; genus Juncus) are grass-like perennials.  Along with grasses and sedges, rushes are monocots (monocotyledons), plants with a single seed leaf.   The other large category of flowering plants, the dicots (dicotyledons) have two seed leaves.

Unlike grasses – which have flat leaves or ‘blades’  - rushes may have only rudimentary leaves.  Their stems are round in cross-section.  In fact, a good way to remember the difference between rushes and sedges is the old saying ‘rushes are round and sedges have edges’.   Sedges, with triangular stems, do indeed have edges.
 



Rushes have rather distinctive flowers, in five whorls of plant parts arranged like spokes of a wheel around the flowering stem.  The flowers are usually white or green-gold to pinkish, small and not as showy as many common garden plants.  That may explain why this group has received less attention than it probably deserves.

In the wild, Juncus torreyi grows in moist areas, including marsh and stream edges, in wet meadows and around lakes/ponds.  Because it tolerates somewhat alkali and salty conditions, it can also be found in brackish tidal marshes, alkali sloughs and other locations with moist, alkali soils.

In colder climates, Torrey’s rush is usually a slowly spreading component of a complex ecosystem that includes many species of rushes and sedges.  In warmer climates – and particularly when competing wetland plants are absent – it spreads easily, creating dense stands if conditions are favorable.  In fact, this is one thing to remember when planting Torrey’s rush.

Torrey's rush (Juncus torreyi) in fall - Mother Nature's Backyard
 
The stems of Juncus torreyi are a pleasant medium green.  In lowland S. California, the plants look best in spring and fall, when days are sunny but soils a bit cooler than in summer.   The stout, un-branched stems are 1-3 ft tall, emerging from an expanding clump.   The stems create a fountain-like cluster that is neat and attractive (see above).

Torrey’s rush reproduces both vegetatively (via underground stems or rhizomes) and by seed in western Los Angeles county.   New plants from rhizomes emerge at distances of six inches or more from the parent plant, often when the ground warms in spring.    You can dig them up when the ground is moist and plantlets are small. 
 

Torrey's rush - flower heads in summer are showy
 
In addition to attractive green foliage, Torrey’s rush has some of the most attractive flower and seed heads of any native rush.  Plants flower in summer – usually June to July or early August in coastal S. California.   The flowers are arranged in spherical clusters, about ½ inch in diameter, which are green-pink in summer.  In fall, the mature seed capsules, which are narrow and pointed, give the cluster a bristly appearance.  Their color, shape and size are unique and showy (see below).
 

Torrey's rush: fall in Mother Nature's Backyard

Torrey’s rush reproduces very well by seed in lowland S. California.  In fact, you may find new little seedlings in moist areas of your garden. The tiny seeds are spread by wind, water and even on the feet of waterfowl.   Fortunately, seedlings are similar in appearance to their parents and easily identified.  We suggest pulling them up when small and easily uprooted.  Larger plants have tenacious roots!

Like most rushes, Torrey’s rush likes full sun and regular to occasional summer water.  In our clay soil, we water this plant every 2-3 weeks in the heat of summer.  Plants are not particular about soil texture and do wonderfully in clay.   They can tolerate slightly alkaline and salty soils.   This is a very easy plant to grow, requiring only minimal effort.   Old, yellowed stems should be removed in early winter and the entire clump can be cut back to 2 inches to rejuvenate it. 
 

Dead and dying leaves should be pruned out in early winter
 
As noted above, Juncus torreyi spreads by both seed and rhizomes.  This is either good or bad depending on your needs.  If you want to limit its spread, we suggest planting it in a large container.  You will be able to enjoy its beauty while limiting its expansion.  We suggest you read our posting on ‘Wetland in a Pot’ for more tips: http://mother-natures-backyard.blogspot.com/2013/05/guilt-free-gardening-grow-wetland-in-pot.html

Anyone who grows Torrey’s rush needs to watch for seedlings and remove unwanted plants promptly.   They can pop up any place that gets regular water, including in pots.
 

Torrey's rush in rain garden - Mother Nature's Backyard
 
That being said, Torrey’s rush is a lovely addition to the fall garden. It adds a decorative vertical element to the garden design.  Its fresh green stems and showy flower/seed heads are a welcome sight in fall.  We like Torrey’s rush in containers and around the edge of rain gardens and infiltration swales.  It’s a useful background plant in areas that get a little extra water.   The species is often used in wetlands restoration projects, particularly in areas where its roots can stabilize banks.    Birds - particularly Lesser Goldfinches in Mother Nature's Backyard -  occasionally eat the seeds.   

Torrey's rush borrows a little water from the neighbor's lawn
Redondo Beach, California
 

 


For more pictures of this plant see: http://www.slideshare.net/cvadheim/juncus-torreyi-web-show

For plant information sheets on other native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html

 


 

 

We welcome your comments (below).  You can also send your questions to: mothernaturesbackyard10@gmail.com
 
 
 

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