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Carex pensylvanica

 

Pennsylvania sedge comes from the large and confusing Cyperacea or sedge family. Investigations into plant data bases reveal a variable description of the plant itself (including variations in flower time and color) but for the purposes of this writing it is sufficient to say that Pennsylvania Sedge has an attractive grass like foliage that usually grows to 6” in length (sources note anywhere from  4-18”).  Carex pensylvanica produces a shiny dark green leaf throughout the growing season that turns light brown in the late fall that remains persistent throughout the winter providing good wildlife cover for birds. As a cool season plant, growth occurs early in the spring with bright green growth emerging from the center of the plants.

This zone 3 (-40F) sedge has a very stoloniferous habit meaning it spreads underground quickly allowing separate plants to form a thick cover quickly. Pennsylvania Sedge naturally occupies dry, open woodland sites from New Brunswick to North Dakota south to Tennessee. In eastern Long Island, it grows in open areas and under trees on the flats in back of the dunes and throughout the Oak forests. It is a plant that moves into open woods and especially in areas that have recently been disturbed.


It is common to find Carex pennsylvanica spreading across the woodland floor after intensive logging, destructive insect canopy reduction or other widespread forest disturbances. Although it does not survive hot fires well (the root system does not penetrate more than 4” in depth), it can quickly spread across burn areas by aggressive colonization from unaffected outer perimeters before other plants can gain hold, in many cases covering the site within two years.


The plant is tolerant of many soil types and although preferring dry slightly acidic loamy soils, it grows quite well in soils ranging from clay to sharp white sand. Drainage is important, standing water is most often fatal in the winter months, but it will tolerate occasional flooding quite well.

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Once this Carex is established, it produces a beautiful cover of glossy, thick foliage for sunny to shaded areas. The species is extremely drought resistant, and after establishment, requires no additional irrigation, fertilizer or pesticide application. We commonly use this Carex in springtime plantings (in some cases in pure white sand in full sun) and in the first year, with the exception of two supplemental waterings (if needed during the worst of the summer drought), the plants do not receive any irrigation. After first year establishment, it is not necessary to water any of the Carex plantings. The plants typically grow a moderate amount during the first year but after one over wintering cycle, in which the rhizomes spread underground, new shoots emerge in the spring to cover an area approximately two to three times their former spread. They continue to increase their rhizomes mat throughout the growing season until they form a beautiful green forest floor covering.


This plant provides an excellent solution for no maintenance ground cover and, with great enough numbers, no mow lawns for partial shade environments. In the northeast Carex plants grown in deep, heavy shade do survive but they seem to have better vitality with at least moderate shade cover and as mentioned above Carex does very well in full sun exposures. Due to the mat forming growth of Carex, fertilizer, soil amendments, pesticide and herbicide applications are not necessary and may actually encourage rank weed growth. It has been our experience that if the growing conditions that Carex prefer are provided, dry shady sites with poor soil, that Carex out performs and out compete weeds in the planting beds which has made the use of any chemical applications in our plantings unnecessary.


Carex pensyvanica provides nesting habitat and cover for migratory waterfowl as well as ground bird populations. I have seen deer sleep on top of Carex beds but have never witnessed or heard of deer eating Carex or even browsing the new growth.


Our planting schedule for revegetation and landscape work with Carex most often calls for springtime planting (any season the soil can be worked is fine) in quart pots planted from 1 ½’ to 3’ centers for coverage in two years depending on the client needs. The closer plantings can be thinned out in a couple of years without detracting from coverage with the transplants moved into surrounding areas. A mulch of leaves (entire or  ground up with a mower) can be placed between the plants will help to hold down weed germination and conserve soil moisture.


Carex  pensyvanica is an excellent plant as for use as a naturally occurring, attractive, drought resistant, no maintenance groundcover for the back dune, forest, field and home environments.

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