During the past twenty years, developers of residential communities have been
encouraged to set aside open space or common lands in an effort to enhance the rural character of suburban communities and provide habitat for wildlife. These open spaces
often include wetlands that cannot be developed and rocky sites that would be costly to convert into residential lots. However, in many better designed communities,
relatively large open areas are preserved as meadow or forest. Such undeveloped common lands are often the pride of suburban communities and their presence enhances the value of residential lots.
In time, the character of these valued open spaces can change, usually not for the better. A meadow that provided vistas of wildflowers and enhanced the sense of
spaciousness can be invaded by Autumn Olive (Elaeagnus umbellata Thunb.), Bullbriar (Smilax rotundifolia L.) and Red Cedar (Juniperus virginiana L.), producing an unsightly
and impenetrable thicket . This encourages the attitude that these meadows should be planted to grasses, mowed regularly, and used as informal athletic fields. Such
conversions are at times useful and serve the community well, but often people prefer to retain the meadow, enjoy the solitude, and observe the birds and wildflowers.
Is it possible to arrest the progression to weedy thicket without undue maintenance? Yes, if certain principles of plant communities and biodiversity are recognized.
First, it must be remembered that open upland meadows are not natural plant communities for most of New England. When the European settlers arrived, the East
Coast was forested. The only open spaces were tidal marshes, sand dunes, and some inland bogs. Most of the land was dominated by an oak, hickory, and chestnut forest
or some variation of that. Today's meadows are usually abandoned fields that were once planted to crops or used as pasturage for livestock. When left to their own
devices, such sites support a succession of plant communities, eventually culminating in a mixed hardwood forest. In short, a meadow is not a stable vegetative community
in New England, and it will not persist without human intervention.
However, meadows can be managed to retain their open character and provide habitat
for desirable plants, birds, insects, and mammals. But their management is a long-term undertaking that should be accommodated in the community's budget for landscaping and maintenance.
Two Basic Approaches to Meadow Management
One approach to meadow management is to create a prairie meadow populated with
wildflowers and warm-season perennial grasses. The objective is to create a community of plants similar to what once prevailed on the western plains, where
antelope and bison grazed and wildfires discouraged invasion of woody species. This approach often requires elimination of existing vegetation as well as destruction of
underground plant parts and much of the soil seed bank. Such site preparation is labor- intensive and frequently requires two or more years to complete. Prairie
establishment can also require considerable labor because the warm-season grasses, which constitute the core prairie vegetation, are slow to establish, and seeding of
broad-leaved flowering plants should be delayed by one or two years, until the grasses take hold. However, once established, it can be maintained with relatively little
effort_annual mowing or burning but little else. Creating a new prairie meadow is often more work than a community landscaping committee is willing to undertake.
An alternative, less labor-intensive approach is to start with what is already present and manage the site so as to encourage desirable species while discouraging
unwanted vegetation. The work must be spread over several years, but the intensive initial effort can be avoided. Also, the site will not require denuding, leaving it
vulnerable to erosion. For most southern New England residential meadows, this may be the most realistic approach to take.
Establishing the Meadow
The first step is to determine how the land was previously used. Was it planted to a field crop (corn, potatoes, nursery stock, etc.), or was it used as a pasture or hay
field? If the former, vegetation will include successional plants ranging from herbaceous weeds to deciduous trees. If it was a pasture or hay field, the sod of
cool-season grasses probably will still be evident.
How easily the site can be enhanced and maintained as a meadow will depend on its
history. A field used to grow crops will have a complex assortment of mostly perennial plants but not a well developed sod. It will have fewer grasses and more areas of
exposed soil, providing space for a number of woody invaders that, if ignored, will turn the site into a thicket. A few woody plants such as Red Cedar (Juniperus virginiana L.)
are not objectionable; their evergreen columnar shapes add visual interest and provide protection for birds and other small animals. But if red cedars are allowed to become
too numerous, the meadow is lost and the cedars are eventually displaced by larger trees. Invasive exotics such as Autumn Olive (Elaeagnus umbellata Thunb.) and Asian Bittersweet
(Celastrus orbiculatus Thunb.) cannot be tolerated. Greenbrier (Smilax sp.) and Poison Ivy (Toxicodendron radicans (L.) Kuntze), though native, are also
undesirable. Maintaining a meadow is a constant battle to prevent these plants from invading and gaining dominance.
While former crop lands are more prone to woody invaders, they are also more easily revegetated by desirable species. Close mowing or burning followed by overseeding
with mixtures of meadow perennials can quickly increase botanical diversity and visual interest. Several seed companies have formulated seed mixes that contain species
that are adapted to open sites and will maintain themselves if woody invaders are kept at bay. (Many species included in these mixes are not native to Rhode Island, but
remember, there are no native upland meadows in the state.) Some mixes also contain several warm-season and cool-season bunch grasses; they will not produce a dense
sod but should maintain a constant ground cover that will limit invasion by undesirable woody species.
The best time to overseed a meadow is early-to-mid fall when weed seed germination
is reduced. Drilling the seed or disking it into the upper half inch of soil will increase germination and establishment without causing excessive damage to existing
vegetation. Many seeds will not germinate until the following spring, when they will offer some competition to germinating weeds. It will take two to three years for an
overseeded meadow to reach its full glory, and the overseeding may have to be repeated if the initial seeds failed to germinate or if the plants did not become well established.
Maintaining the Meadow
Once a desirable stand of meadow grasses and flowering perennials is established, it can be maintained by mowing or burning once a year. Opinions vary as to when a
meadow should be mowed or even if an annual mowing is necessary. Mowing mimics the burning and grazing that traditionally supported the persistence of prairie
communities. Burning prevents invasion of woody plants, keeps perennial cool-season grasses at bay, and strips organic residues from the soil surface, allowing the soil to
warm early in spring. Once a meadow is established, mowing can replace the need for burning. A mid-spring close mowing is best: most meadow perennial wildflowers will not
have emerged by then; perennial cool-season grasses will have begun growing and should be cut back by close mowing; woody invasives will also be cut down and forced
to regenerate from basal buds. Dicotyledonous perennials will gain enough of an advantage to permit them to compete with the grasses and invasive woody plants.
Spring mowing will also permit maximum seed production of desired plants, so that if the site is disturbed or plants killed, the meadow can regenerate. Leaving the plant
stalks in place during the winter will reduce the number of soil freeze-thaw cycles and insure greater plant survival. Insects will also be able to overwinter if meadows are not
mowed until mid-spring. Thus, spring mowing appears to offer advantages for preserving diversity while discouraging weedy invasives.
In contrast, a meadow that was recently a cool-season grass pasture or hay field will likely retain a grass sod that resists weedy invasion. Such a meadow can be managed
by mowing during early spring. However, its cool-season perennial grasses need light to survive over the winter; they will not tolerate heavy shade from high growth
produced during the past summer. If a grass meadow is mowed in fall, the hay should be removed so plant crowns receive light. If the summer's growth was excessive and
mats down, shading plant crowns, fall mowing may be advisable.
Introducing Botanical Diversity
A cool-season grass meadow will lack botanical diversity. Seeding a prairie mix in such
a meadow will not succeed without first weakening the grass sod. Very close mowing or use of a herbicide can severely damage the sod, exposing the meadow to weed
invasion and possible erosion. If greater plant diversity is desired, herbicides can be used on a limited basis to create bare islands or borders in which perennial prairie
plants can be seeded or planted. For two or three years these areas will be vulnerable to weeds, but their smaller size will make weed control manageable. Once these
islands are established, they can be mowed along with the meadow.
The best way to remove grass sod from small areas is by spraying the vegetation with
glyphosate (e.g., Roundup) at the rate recommended on the label. Glyphosate is recommended because it is highly unstable in soils and leaves no residue. It can
persist for several weeks in plant tissues but is quickly degraded by soil microbes to simple inorganic materials. It is readily absorbed by leaves and moves to growing
points (shoot and root meristems) where it kills dividing cells by inhibiting the synthesis of several critical amino acids required for protein synthesis. The herbicide is most
effective if applied when translocation of photosynthetic products out of leaves is rapid. Normally this is when leaves are fully expanded and shoot and root growth are in
progress. Also suitable is late summer, when leaves are healthy and energy reserves are being replenished.
G
lyphosate is a nonselective herbicide_it kills any plant that absorbs the material through its leaves. Nearby desirable plants should be protected from its spray. Apply
any herbicide only on calm, windless days to avoid inadvertently damaging or destroying desirable plants.
To create an island or to clear a site for seeding, mow the grass in mid-August, then
remove the cut grass and allow it to regrow to about a foot tall.
Apply Roundup at the recommended rate and do not disturb the site until the following
spring. By mid-May, the sprayed areas should be free of any living vegetation. Cultivate the dead grass into the soil and seed the area with desired species. Better
yet, set young plants directly into the dead grass, which will serve as a mulch and inhibit weed establishment. No fertilizer is needed unless the soil is of poor quality, as
evidenced by off-color vegetation and weak growth. Most meadow plants grow best in a moderately acid soil. If a soil test shows that the soil is too acidic (pH below 5.5),
apply ground limestone and, if practical, incorporate it into the soil to a depth of 6 inches. Lime applied to the surface takes longer to raise pH.
Selecting native or naturalized plants will give the meadow a natural appearance, and these plants will adapt to local conditions. Naturalized plants, though often regarded
as weeds, will be at home in a botanically diverse meadow. Oxeye Daisy, Black-Eyed Susan, Joe-Pye Weed, Chicory, Milkweed, Lupine, Yarrow, and Coneflower are among
those compatible with a cool-season grass meadow.
Extensive plant lists are available. The Lady Bird Johnson Wildflower Center, Austin,
TX, (www.wildflower.org) lists recommended plants for the Northeast. Prairie Nursery in Westfield, WI, (www.prairienursery.com) has assembled a list of suitable plants for
the Northeast, many of which are offered for sale. Instructions for establishing a meadow are also given. The New England Wild Flower Society (www.newfs.org) offers seed mixes and seed.
One final consideration is elimination of undesirable woody plants. Large ones can be cut down, although most will regrow from basal buds or rootstocks. Repeated cutting
will eventually deplete their energy reserves, and they will die. If this approach is impractical, herbicides can be used. Here a greater variety of materials can be
employed, but Roundup may again be the material of choice. Spot applications to the woody plant regrowth during late summer or early fall should do the job, although a
follow-up treatment the following year may be needed for well established plants. Greenbrier should be sprayed in late spring because its mature leaves are not easily penetrated by herbicide.
There is still much to learn about residential meadow management, but a beautiful, botanically diverse meadow can be created and maintained with reasonable effort if
you understand the problems involved and the principles underlying their solution.
Richard Hull, Ph.D., is Professor Emeritus of Plant Science at the University of Rhode
Island. He served as co-president of RIWPS for two years.
MEADOWS IN THE FORECAST?
by Will Green
The managed meadow is hard to find in Rhode Island. There are, however, landscapes we consider to be akin to meadows: abandoned farms and other vacant lands,
highway edges and large detention basins. What they have in common is that they are unforested and not managed for their vegetation, habitat or aesthetic values. Instead
they are lands that are indiscriminately mowed (along highways) or in the case of abandoned farms and pastures, they are lands in transition.
We enjoy seeing these grassy and weedy landscapes with summer blooms and flitting birds or butterflies. They contrast with their surroundings, providing views to the
horizons and distant treelines, and habitat to a host of plants and animals specifically adapted to these areas. So why don't we see more New England style meadows?
As Richard Hull and many others have pointed out, meadows are not natural to Rhode Island: therefore, undeveloped lands only pass through this phase of succession on
their way to becoming forest. To impose this landscape on RI towns requires that municipalities legislate for meadows, an unlikely occurrence on either public or private lands.
Municipalities in Rhode Island manage private development through zoning ordinances and subdivision control legislation. Through this legislation, zoning districts are
established along with building requirements and permitting procedures. Towns are not in the business of dictating how private landowners manage their lands, except where
the health, safety and welfare of a community are at stake (wetlands, aquifers and hazardous activities). Towns are equally unlikely to maintain public lands as meadow,
since this landscape requires more maintenance and resources than a forest (which are often maintained with benign neglect). However, with current concerns about
overdevelopment, sprawl, and the quality of air and water resources, many towns have adopted alternatives to the traditional single family subdivision—alternatives that
may also provide opportunities for establishing meadows.
Cluster housing, conservation subdivisions, and special mixed-use districts are
examples of these. In each case, traditional lot sizes and layouts are replaced by designs intended to result in fewer disturbances to the land, lower development costs
and preservation of open space. It is during the design phase for these projects that decisions about the use, character and location of open space are made. If the
developer—or at a later date, the community—decide that they want to establish a meadow on community-managed land, it can be achieved much more easily than by
trying to persuade a number of individual small landowners to convert their landscape. The results of a community managed meadow can also be more rewarding than that of
individual attempts at creating such a landscape, since a larger area will provide more species specific habitats.
While forests and meadows require different expenditures of time and money, there are benefits to having both. When the land is in the public sector, a town's comprehensive
plan and budget will determine what areas will be and how they will be maintained. With towns struggling to manage development and maintain infrastructure and
facilities, the best hope for creating and managing meadows, as well as other large undeveloped open spaces, seems to be through alternatives to traditional single-lot
development patterns. Through the use of these alternatives, municipalities and their citizens can still reap the benefits from meadows and other valuable landscape forms.
Will Green is an Associate Professor of Landscape Architecture at the University of Rhode Island, where he teaches and hosts a public lecture series. His research
interests include sustainable design and development, and perennial planting design.
INVASIVE ALERT: WATER CHESTNUT (Trapa natans)
by Rick Enser
The past few years have seen a rising interest in water gardening with the construction of small backyard ponds vegetated with an assortment of exotic plants.
Water lilies, horsetails, spike rushes, and even the common native three-way sedge (Dulichium), which has been offered at some nurseries under the pseudonym of "Dwarf
Bamboo," comprise a new assemblage of garden plants. Included in this mix are a few warm-climate species, such as Water Hyacinth and Water Lettuce, that have
occasionally been discovered in rivers and ponds, likely resulting from the disposal of plants by careless persons. Luckily, New England winters succeed in eliminating these
interlopers from Rhode Island's natural habitats so they have not become the invasive problems experienced in southern states. However, one plant does have the potential
to become a true nuisance in this area: European Water Chestnut (Trapa natans).
Water Chestnut was reportedly introduced to North America in New York about 1874
and was known to be cultured in the botanical garden of Asa Gray in 1877. However, by 1879 it was already being found in the Charles River. Despite its attractiveness, Trapa
is capable of growing aggressively. With stems up to 16 feet long, the primary part of the plant is a foot wide rosette of floating leaves that can multiply to produce
extensive mats that deplete oxygen, resulting in the demise of other aquatic plants and animals. But more insidiously, Trapa produces a 1.5-inch wide fruit capsule that is
extremely hard and armed with spines sharp enough to puncture tires and cripple horses and dogs, not to mention beach strollers. Incidentally, the name Trapa is derived from the Latin
calcitrapa in reference to a caltrap, the name for a four-spined iron ball that was used in ancient warfare to hinder advancing enemy cavalry.
This plant has become such a nuisance in Massachusetts that a law was passed in that state specifically banning the spread and growth of Trapa natans. (Unfortunately,
it is already well established in several places, including the Great Meadows National Wildlife Refuge in Concord, where hundreds of thousands of dollars have been spent trying to eliminate it.)
Although Water Chestnut has to date not been found in Rhode Island waters, state biologists are fearful of its eventual appearance. This plant is not banned from sale in
this state and is reportedly still being sold by a few local nurseries and pet stores. The Rhode Island Wild Plant Society encourages people not to purchase this plant, and to
let retailers know of the potential dangers of its escape. Any plants found in local waters should be immediately removed and properly discarded.
Richard Enser is Director of the R.I. Heritage Program and serves on the RIWPS Board of Trustees as second vice-president and Chair of the Display Committee.
ALL IN THE FAMILY: The Milkweeds_Asclepiadaceae
by Richard J. Hull
