Is it Pampas Grass or another type of ornamental grass?
I doubt that he really has pampas grass (Cortaderia spp.) because it
is not generally considered winter hardy in our climate. Some
varieties are hardy to USDA Zone 6, but most pampas grasses are only
hardy to USDA Zone 8. It may be one of the maiden grasses (Miscanthus
spp.) or Ravenna grass (Saccharum ravennae). Any of these can
quickly outgrow its space in the garden. Most of our ornamental
grasses are warm season grasses. They are best planted and/or
divided in spring only; fall divisions often fail because they do
not have time to become established before winter cold hits.
Removing ornamental grasses
Getting rid of an overgrown, well-established ornamental grass can
be a chore. They usually have large root systems and are very
difficult to dig up. Rather than trying to dig the entire clump up,
you can dig it out piecemeal. If you leave many roots behind, they
will probably re-sprout next spring. Just continue to dig the
re-sprouts out, and eventually you will be rid of it.
It will be too late to spray by the time this article goes to press,
but late summer-early fall applications of a non-selective herbicide
such as Round Up (glyphosate) can be very effective. If you can find
Roundup Pro or one of the 41 percent glyphosate knockoffs like
Eraser (Agway), it would probably be more effective than the
homeowner formulations you typically find at the big box stores.
They are more likely to be available at a commercial turf and
landscape or farm supply store.
Since glyphosate is non-selective,
you must use it carefully to avoid getting any of the spray on
desirable plants or lawn areas. It takes 10-14 days for glyphosate
to work, so do not be discouraged if the grass does not die
immediately after you spray it. Ornamental grasses are tough, and it
might take more than one application to get rid of it for good.
Best time for chemical controls
Late summer-early fall is a good time to make herbicide applications
to control perennial weeds and plants you want to get rid of because
they are translocating the products of photosynthesis down to their
roots for storage over the winter. They take the herbicide down to
the roots quite readily too, resulting in more complete control.
Spring applications are often not as effective because the movement
of sap in the plants is up and out.
Photos of grasses
African Violets blooming