Carexes and other grasses

Good grasses

The LRB Management Committee has planted a range of native grasses around streams and the wetland in the reserves. The most commonly used are the native grasses Carex secta and Carex virgata.

Pest grasses

Carex divulsa

A common grass around Auckland gardens is Carex divulsa, it's quite robust and not unattractive but it is an introduced plant and one which was proposed as a Surveillance species in the new RPMS for 2009.

The "Carex in Auckland" book states:

"Is capable of forming large colonies under trees in parks, on farms, in native forest and areas to be revegetated. Its preferred habitat is similar to the conditions required for revegetation projects. It is now quite widespread throughout the region although not yet in large numbers. It is evident that cultivated plants have escaped from gardens to form problem wild infestations. It is easily mistaken as a native because of its common presence in some native bush. An effort to restrict its spread and to protect conservation areas is required."

From DOC, here's advice on control:

Can be pulled up quite readily by hand but watch for subsequent seedlings. Obviously don't just pull seeding plants and leave them on site - take the seed heads away and destroy them, or pull the plants when they are without heads or just in flower if you don't take the eradicated plants off-site.

Spray with 1% glyphosate (where product contains 360g/L ai) plus pulse.

Carex longebrachiata

Dense clump-forming, does not open up with age. Tolerates fire, hot to moderate cold, wet to drought, wind, salt,

poor soils, damage and grazing, semi-shade. Produces many well dispersed, long-lived seed in open areas.

Tough roots cannot be pulled by livestock.

Seed spreads via water, livestock pelts and hooves, contaminated seed, soil and machinery.

Forms dense (occasionally pure), long-lived stands, preventing native regeneration. Remains as obstruction (not

seeding) under regenerating canopy, delaying regeneration process. Fire hazard, harbours rats and mice.

Potential invader of shrubland, regenerating forest, short tussockland.