Gardening with Native Grasses in Cold Climates is now available through the University of Minnesota’s Press Books. With help and guidance from University of Minnesota librarian Kristen Mastel, authors Diane M. Narem and Mary Hockenberry Meyer released the new digital version of this book in November 2020.
Gardening with Native Grasses in Cold Climates and a Guide to the Butterflies They Support was originally published in May 2018. The previous version was only available on Apple platforms, limiting who could access the information.
The new version is available for free from the University’s digital library collection. You can download the entire book or read it online.
The book is divided into five chapters:
Introduction to Grasses
Benefits of Native Grasses
Common Native Grasses of the Northern Midwest
Planting, Maintenance and Management
Grass Selection and Butterfly Pairings
Gardening with Native Grasses in Cold Climates, is written for inexperienced as well as seasoned gardeners, landscape designers, garden center employees, and anyone interested in native grasses that grow well in cold climates. New information on the benefits of native grasses including their importance as host plants for native Lepidoptera is included. Combinations of specific grasses used by larvae and perennials that the adult butterflies feed on is new and timely information.
Information in the book is based on research conducted by Narem and Meyer. Tables, plant lists and numerous illustrations are also included.
The 2019 USDA Census of Horticulture Specialities is complete and figures for ornamental grasses were $178,791,000 in sales for 1,991 businesses. Grasses continue to grow in sales, up 13% from $158,061,021 in 2014, and $124,261,118 in 2009. In 2019 Florida had the top sales with more than $11M, followed by California with $7.5M. Eights states sold between $1 and 2 million in ornamental grasses: Alabama, Georgia, Louisiana, Maryland, Michigan, Ohio, Oregon and Texas. Grasses continue to increase as important landscape plants.
Early spring is time to clean up grasses. Dale Nemec at Scott Arboretum at Swarthmore College has a good video of how he cleans up the grasses in the spring. He uses a variety of tools on several different grasses. Spring cutback means more vigorous plants. Minnesota Landscape Arboretum gardeners sometimes use a mower set high to clean up sedges as shown below.
Northcreek Nurseries recently made the decision to stop selling Carex flacca, blue or carnation sedge, due to information from botanist Dr. Robert Naczi of New York Botanic Garden that Carex flacca is spreading beyond the garden. Also know or sold as ‘Blue Zinger’, Carex flacca is native to Europe but has been documented in Canada and the U. S. as early as 1894. Northcreek is recommending replacing C. flacca with similar blue-foliage native Carex species, such as Carex flaccosperma, Carex platyphylla, or Carex laxiculmis Bunny Blue® ‘HOBB’.
In Minnesota, Carex flacca has not been invasive beyond where it is originally planted. It does have significant rhizomes, which are certainly something to consider when planting this zone 4 winter hardy, almost evergreen ground cover. The planting below shows a great use of Carex flacca on a steep slope in late March at the Minnesota Landscape Arboretum. Some years, if the foliage is more brown than green in early spring, gardeners mow off the plants with lawn mower blade set at 4 inches.
This close up of blue-green sedge shows its dense foliage with blue-green coloration. We will continue to monitor this plant for invasiveness and report any further findings in Minnesota at this website. We appreciate Northcreek sharing their information so all gardeners can be aware of changes in plants in managed and natural landscapes.
Heavy wet snow can knock down the biggest of grasses. But Molinia ‘Karl Foerster’ below, with its pencil-thin stems was not affected. Still green and growing on Oct 22.
Look at the ‘skirt’ surrounding the standing center of giant miscanthus at the Minnesota Landscape Arboretum. This snow came on October 22, with thunder and much moisture that snapped the bamboo-like stems of giant miscanthus. Note the green tops, as the plant was not dormant.These stems did not recover after the snow melted, but if the stem is not broken, grasses can rebound after some snow.
Because switchgrass, Panicum virgatum, is native to almost every state in the U. S. it has a wide variation of growth habits and forms. Shown above are newer forms, from the left, Bad Hair Day, Purple Tears, Blue Fountain, and Apache Rose on Sept 17, 2020 at the Minnesota Landscape Arboretum Grass Collection.
‘New Wave’ is 5 to 5 1/2 feet tall with yellow foliage and ‘Blackhawks’ is closer to 6 feet, with dark red or purple foliage. Both of these new cultivars are more upright, at least at the Minnesota Landscape Arboretum, than other big bluestem cultivars.
Native to Minnesota and much of central U.S., purple lovegrass, Eragrostis spectabolis, is a warm season bunch grass that grows only 12-18 inches in height. Showy with red flowers as seen on July 30 at the Minnesota Landscape Arboretum.
In mid July we see the changes from cool season to warm season grasses; northern lawn grasses have flowered and if not cut, the flowers are turning brown. These flowers are past anthesis or pollen shedding and the stems will begin to senesce or die as they turn brown. Kentucky bluegrass, the European meadow grasses so prevalent in the U.S. such as orchard grass, and brome grass are cool season grasses. ‘Karl Forester’ featherreed grass is a common cool season grass, shown in the left photo below in early July just past flowering, and again in September with brown stems in the center back and extreme right of the right photo.
Warm season grasses are the reverse and are just beginning to come “out of the boot” or stem and are beginning to show their flowers and shed pollen in mid-July. From late July through September warm season grasses are in full flower and at their peak. Big and little bluestem, blue grama, prairie dropseed Indian grass and switchgrass are warm season grasses. Little bluestem Blue HeavenTM is on the right photo in the front, below the maple tree, showing its red fall color in September. Use both cool and warm season grasses in the landscape to take advantage for their diverse growth patterns.