Q. I have tried digging this weed up but it comes back. I
have tried both Roundup and Spectracide according to the package directions,
and even painting it on the foliage full strength.
have tried both Roundup and Spectracide according to the package directions,
and even painting it on the foliage full strength.
Although it starts out pretty small, if I miss pulling
one up, they get quite large. Any assistance in getting rid of this plant is
greatly appreciated.
one up, they get quite large. Any assistance in getting rid of this plant is
greatly appreciated.
 |
| Judging from the roots which actually look like a rhizome I believe this is nutgrass. |
A. Judging from the pictures you sent this is one of the
nutgrasses or nutsedge. The roots sure look like it to me. To be sure if it is
one of the sedges and not a grass, cut the top of the weed off at its stem just
below the leaves. Roll the stem between your fingers and see if the stem is
triangular rather than round.
nutgrasses or nutsedge. The roots sure look like it to me. To be sure if it is
one of the sedges and not a grass, cut the top of the weed off at its stem just
below the leaves. Roll the stem between your fingers and see if the stem is
triangular rather than round.
Sedges have
triangular stems in cross section. Rolling the stem between your thumb and
first finger you should “feel” the triangular bumps of the stem and the stem should
not feel round.
triangular stems in cross section. Rolling the stem between your thumb and
first finger you should “feel” the triangular bumps of the stem and the stem should
not feel round.
 |
| Nutgrass with nut attache to the rhizome or “root”. |
Sedges,
like nutgrass, are more difficult to kill than grasses. Nutgrasses have
underground “nuts” attached to the “roots” which are really underground stems
called rhizomes. These nuts grow into new plants if they are separated from the
mother plant or the mother plant is killed.
like nutgrass, are more difficult to kill than grasses. Nutgrasses have
underground “nuts” attached to the “roots” which are really underground stems
called rhizomes. These nuts grow into new plants if they are separated from the
mother plant or the mother plant is killed.
This is
why pulling, hoeing or using chemical weed killers do not work on this plant. As
you have found out, spraying the tops with Roundup or dandelion killer “burn” the
tops back but release the growth of the nuts.
why pulling, hoeing or using chemical weed killers do not work on this plant. As
you have found out, spraying the tops with Roundup or dandelion killer “burn” the
tops back but release the growth of the nuts.
 |
| Triangular stem of nutgrass in cross section. |
These
nuts are usually anywhere from 4 to 8 inches below the soil surface. All you
have done is kill the mother plant and the baby plants released from the nuts that
pop from the ground grow like they are on Red Bull. Pulling nutgrass from the
soil easily separates the nuts from the mother plant with the same result.
nuts are usually anywhere from 4 to 8 inches below the soil surface. All you
have done is kill the mother plant and the baby plants released from the nuts that
pop from the ground grow like they are on Red Bull. Pulling nutgrass from the
soil easily separates the nuts from the mother plant with the same result.
What to
do? There are two basic approaches toward getting some control. The first is
soil replacement. If it’s a small area, you can dig down 12 to 14 inches deep,
remove the soil and replace it with clean soil. You can take the soil and put
it in a clear plastic bag in the middle of summer and “cook” it using the sun.
do? There are two basic approaches toward getting some control. The first is
soil replacement. If it’s a small area, you can dig down 12 to 14 inches deep,
remove the soil and replace it with clean soil. You can take the soil and put
it in a clear plastic bag in the middle of summer and “cook” it using the sun.
You can
starve out the nuts. If you continue to remove the tops at the soil surface,
over and over, before they get more than two or 3 inches tall it is possible to
exhaust or starve the nuts so that they die. If you pursue this option you have
got to stay on top of it or it will not work
starve out the nuts. If you continue to remove the tops at the soil surface,
over and over, before they get more than two or 3 inches tall it is possible to
exhaust or starve the nuts so that they die. If you pursue this option you have
got to stay on top of it or it will not work
I am surprised glyphosate did not work. It is best to water the area by spraying water on well the day before. Not only does this induce the "grass" to grow which is good for herbicide uptake, but it washes any dust off the "grass" blades that will irreparably inactivate the glyphosate. Apply glyphosate per directions (rather than concentrate) in the early morning when plants are active. Then you need patience while the poison slowly infiltrates all of the plant and eventually kills it.
I have used this for control:
http://www.montereylawngarden.com/product_information.aspx?242000p=0eff7eb8-13e2-4ab4-aa3c-0061695c838f&240000p=fc491925-2436-4259-afbf-bf4723251024
But it is expensive for the amount and I have a lot of nutgrass.
http://turf.arizona.edu/publications/Nutsedgecontrol2013.pdf
http://www.lawn-care-academy.com/nutsedge.html
http://oak.ppws.vt.edu/~flessner/weedguide/cypro.htm
http://www.turffiles.ncsu.edu/weeds/yellow-nutsedge
http://www.turffiles.ncsu.edu/weeds/purple-nutsedge