Sneaky Pasture Weeds – Sedges and Rushes

by Kitty O’Neil and Mike Hunter, Regional Field Crops and Soils Specialists

We’ve discussed pasture grasses, legumes, pasture weeds and management ideas for pasture improvement on these pages many times before.  All good topics.  When you call to mind pasture weeds though, I’d bet you picture milkweed, goldenrod, a couple different types of thistles and maybe bedstraw.  These are pesky and important weeds in many pastures, but there are other, sneakier weeds that may escape your attention.  These sly and mischievous weeds require closer inspection and a bit more scrutiny to figure out.

Ideally, pastures are dense, perennial sods consisting of mixtures of high-yielding, palatable grasses and legumes.  In reality, most pastures do not quite match this perfect ideal.  Weeds are normally present in some number, ranging from insignificant to seriously problematic, depending on management and history.  Weed density within a pasture can change over time, and can vary from one area to another within a pasture.  You may notice, in your own pastures or hay fields, that weeds are often not distributed uniformly, but rather that some plant species are concentrated on knolls, along the woods, in wet spots, or in high traffic areas.

A well-managed Northern New York pasture.  (Photo: K. O'Neil, August 2013)

A well-managed Northern New York pasture. (Photo: K. O’Neil, August 2013)

Let’s turn our attention to some particularly sneaky weeds that are often, but not always, found in lower, wetter areas of the pasture – the sedges and rushes.  I’m referring to them as ‘sneaky’ because they’re a bit harder to spot in the pasture.  They look a lot like grasses to an amateur observer, but that is about as far as the similarities extend.  As a group, grasses consist of a jointed stem with a few tillers, long and slender leaves with parallel veins.  They range in height from turf to giant bamboo.  Grasses may be annual or perennial but all have their growing points near the soil surface, so they can survive repeated mowing or grazing.  Grasses reproduce via seed or underground structures.  Most of the hay and pasture grass species (bluegrass, orchardgrass, timothy, fescues, reed canarygrass, etc.) are quite palatable and produce moderate to high yields.

Sedge and rush species also have long slender leaves but occupy completely different branches on the evolutionary tree of life than grasses.  Sedges and rushes are perennials that livestock typically avoid, finding them unpalatable.  There are well over 1000 different sedge species, but the most common sedge found in Northeast pastures and hayfields is Yellow Nutsedge.  Yellow nutsedge is noticeable for its pale green color, spiky flowers and underground tubers, but its most distinctive feature is its stem.  If you compare the lower stems of sedges and grasses, you’ll discover that sedges typically have triangular stems without nodes while grasses have round or flattened stems with nodes.  This key difference is the reason for the memorable phrase “sedges have edges, but grasses have knees.”  Sedges reproduce by underground tubers and rhizomes.

Rushes are short plants that resemble grasses and sedges and are also found in lower, wetter areas of a pasture or hayfield, although rushes may grow in drier or compacted areas too.  The unique feature of rushes is their 3-petal, lily-like flowers.  In fact, botanists refer to rushes as “lilies turned to grass” to help them remember their distinctive flowers.  Rushes reproduce by vegetative rhizomes or by seed.  The tough, wiry, round stems of rushes are also avoided by livestock who generally do not find them palatable.  In the Northeast, the most common of the rushes is Slender Rush.

Nutsedge and rushes might be most noticeable as animals are finished with a pasture or paddock.  The livestock will have eaten grasses and other appealing plants, leaving behind patches of Yellow Nutsedge and Slender Rush.  It is disappointing to see large, uneaten areas of low-yielding, unpalatable pasture, but biological features of rush and sedge make them difficult to control.  Their underground reproductive structures make mowing or clipping ineffective as a means for removal, but this strategy can slow their spread, if it is timed before flowering.  Herbicide options for these two weeds are limited, but Permit and Yukon have recently had hay and pasture applications added to their labels.  They may be used on yellow nutsedge in grass pastures with no grazing restriction for lactating or non-lactating animals.  If the field is not too wet for machinery, suitable grasses or legumes can be overseeded with a no-till drill or, as a more drastic measure, the sod may be killed and soil can be tilled for replanting of appropriate grasses and legumes.  Often though, the sedges and rushes occupy areas that may be difficult to access with tractor equipment.  In this case, the field could be tiled for better drainage if that option is economically advantageous.  Legume species such as red or white clover can be frost-seeded in the spring to try and introduce more desirable species, but the rush and sedge species will likely persist.  Sedge and rush weeds take a keen eye to notice, but their impact can be just as important as thistles or milkweed or goldenrod in a pasture or hayfield.  Their presence reduces overall productivity of the field and presents a challenge to the farm manager.

Additional resources:

  1. Uva, Neal and DiTomaso, Weeds of the Northeast, Ithaca, NY: Cornell University Press, 1997.
  2. Kersbergen, R.  2004. Bulletin #2491, This Old Hayfield: A Fact Sheet on Hayfield Renovation.  U Maine Extension.
  3. Specification Guide Sheet For Pasture and Hay Planting (512), Vermont NRCS
  4. Yukon ( and Permit ( herbicides, Gowan Company.

For more information about field crop and soil management, contact your local Cornell Cooperative Extension office or Kitty O’Neil, Regional Field Crops and Soils Specialist, Cornell University Cooperative Extension, 315-379- 9192 x253;

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Ear to the Ground

by Kitty O’Neil, Ph.D., Regional Field Crops and Soils Specialist

  • Temperatures and growing degree-day accumulations continue to hover above normal across NYS since April 1.    Soils across the state are at least adequately moist; very few areas report dry soils.

- – Accumulations from April 1 to July 6, 2014 – -

Precipitation, inches

GDD Base 50 °F

GDD Base 40 °F









Watertown Int’l Airport







Fort Drum





















Plattsburgh Int’l Airport







Tupper Lake









1 DFN = difference from normal; 2 precipitation days = number of days with ≥ 0.01” precipitation.

  • Corn and soybeans are in and progressing well across the North Country.  Continue to monitor weeds in both crops.  Few insect pests have been problems so far this season in either crop, but monitor soybeans for soybean aphids.
  • Second cutting is progressing slowly.  Recent thunderstorms, wind and hail did not cause much damage to hay fields.  Scout alfalfa for potato leafhopper as a few have been found in alfalfa and soybean fields.
  • Western Bean Cutworm moths are being trapped and monitored across the North Country and the state.  The first moths of the season have now begun to appear in the last 10 days.  Populations have been increasing in the North Country in recent years and peak flight is expected in late July/early August.

Additional resources:

  1. Weekly Crop Progress & Condition Report. 2014.  New York USDA-NASS.

For more information about field crop and soil management, contact your local Cornell Cooperative Extension office or Kitty O’Neil, Regional Field Crops and Soils Specialist, Cornell University Cooperative Extension, 315-379- 9192 x253;

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Small Grains: Harvesting, Handling, Drying, and Storing

Tuesday, July 22, 2014 from 1 to 3 pm at
Gibson Farms, 3861 County Route 21, Schodack Landing

For large-scale & small-scale operations

· Managing machinery and processes for quality grain
· Evaluating grain quality
· What bakers, maltster, and distillers need for quality
· Managing pest in stored grains
· Grain storage safety issues

Please RSVP by contacting Aaron Gabriel, 518-380-1496,

Managing barley, wheat, and other small grains from harvest through storage is a new challenge as growers learn to meet quality standards for the new local markets of brewers and bakers.  Cornell Cooperative Extension and the Carey Institute for Global Good are sponsoring an on-farm workshop, “Small Grains: Harvesting, Handling, Drying, and Storing”. Hosted by Gibson Farms LLC, 3861 County Rte 21, in Schodack Landing from 1 to 3 pm on Tuesday, July 22, 2014.  Gibson Farms has been growing grains on over 1000 acres for many years, marketing to grain companies and local livestock producers. They will share their expertise and explain the various machines and components to their grain business.  Aaron Gabriel, agronomist for Cornell Cooperative Extension, will discuss the principles involved in managing grain from harvest through storage, including pest management and safety.  Machinery and handling will be discussed for both large-scale and small-scale growers.  Quality requirements for small grains to meet the local markets will also be explained.  Please RSVP to Aaron Gabriel (518-380-1496,

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New York State Weekly Weather Outlook – July 10, 2014

From Jessica Spaccio, NOAA Northeast Regional Climate Center, Cornell University

Last week temperatures ranged from 2 degrees below normal to 4 degrees above normal. Most areas received one to two inches of precipitation; a few areas in western and northern NY had half an inch to one inch and areas in central to southeast NY had two to four inches.  Base 50 growing degree-days ranged from 100 to 160.

Weather finally clears!  Dry Thursday through Saturday.  Possible showers and thunderstorms Sunday through Wednesday.

Today will be dry and mostly sunny as high pressure moves in with temperatures in the mid 70’s to low 80’s.  Overnight temperatures will be throughout the 50’s.

Friday will again be dry and mostly sunny with highs in the upper 70’s to low 80’s.  Lows will be in the upper 50’s to low 60’s.

Saturday will be partly sunny with highs in the low to mid 80’s with just a slight chance for showers and thunderstorms. Overnight temperatures will be quite mild in the 60’s.

Sunday will be mostly cloudy with scattered showers and thunderstorms and highs in the low to mid 80’s.  Overnight temperatures will again be in throughout the 60’s.

Monday will be partly sunny with a chance of scattered showers and thunderstorms and highs in the low to mid 80’s.  Overnight temperatures will be in the upper 50’s to low 60’s.

Tuesday will be partly sunny with a chance of scattered showers and thunderstorms and highs in the mid to upper 70’s.  Lows will be in the 60’s.

Wednesday’s highs will be in the 70’s with scattered showers and thunderstorms possible.  Lows will be in the mid to upper 50’s.

The five-day precipitation amounts will range from ½” to 1 ½  ; 7-day amounts will range from ¾” to 2” .

The 8-14 day outlook (July 17 – 23) is showing below normal temperatures and normal precipitation.

Maps of 8-14 day outlooks:

National Weather Service watch/warnings map:

NRCC Drought Page which features the US Drought Monitor map (updated every Thursday):

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