Quack Grass - Ugh!

I finally was able to get out into some of the gardens this past weekend.  I couldn't do any transplanting or planting yet because when I attempted to dig into the soil, my shovel encountered ice.   So, I concentrated on cleaning dead foliage and other minor sprucing up in those areas where it wasn't too muddy to work.

Quackgrass in strawberry bed

I had some welcome surprises.  I found four nice, baby juniper trees that the birds must have brought with them as a thank you gift.  Those will be dug out and transplanted to a more suitable location.  But, then I found a not so welcome visitor:  Quack Grass!  Scientifically known as Agropyron repens, quack grass is a pest that grows nearly everywhere in the United States.  It especially seems to like the Burleigh County desert where I live. 

Quack grass spreads by both root and seed.  The creamy white, three to eight inch long seed spikes appear in August.  Each spike contains 20 to 30 seeds, that once in the soil, can remain viable for up to five years.  And, that isn't the worst that quack grass has to offer.  Within two to three months of germination, the plant begins to form rhizomes which can spread up to 300 feet from the parent plant.  That's a lot of territory that can be covered by one quack grass seed.  But, wait, it gets even worse.  Once those rhizomes are developed, if you damage them with a spade or rototiller, every piece of rhizome that you cut off becomes another plant, with another 300 feet of rhizomes or thereabouts.  It doesn't take very long for quack grass to take over the world.

The key to controlling its spread by seed is to cut the grass down before seed heads have a chance to develop.  The key to controlling the spread by rhizomes is glyphosate, marketed most commonly as Round-up.  The problem with glyphosate is that it is non-selective - it will kill anything green that it comes in contact with.  If the quack grass is in an isolated area, you can spray the glyphosate.  Quack grass, however, is smart, and it rarely grows in locations where it is that vulnerable.  Instead, it likes to twine its rhizomes around the roots of other plants,  nestle itself amongst the branches of the shrubs and extends its roots 50 feet beyond the last topside evidence of it, fooling you into thinking you've gotten it all, when it is really just lying in wait for its next assault on your gardens.

But, I digress.  Back to controlling the nasty stuff.  In locations where I can't spray, I've found a couple ways to still get at it.  I mix glyphosate about one-fourth stronger than the recommended mixture (quack grass is tough and I've found a little more strength in the glyphosate knocks it down a little better) and pour it into a small bucket.  I dip a  very small paint brush into the glyphosate and dab it onto the blades of the quack grass.  Any kind of paint brush will do, but I prefer the foam ones.  They drip less while holding more solution to dab onto the grass blades.  If there is other foliage around that I don't want to take a chance of dripping the glyphosate onto, I cover those with plastic, which I can carefully move from plant to plant as I attack the quack grass. 

You can also wear a heavy, chemically resistant rubber glove and just dip your fingers into the solution and wipe them along the blade of grass.  You need to take the same precautions from dripping on desirable plants using this method as you do with the paint brush method.  I think I have better control with the foam brush, so that is my method of choice.

Quack grass will generally need multiple applications of glyphosate.  Glyphosate works on actively growing plant tissue.  Only a small percentage of the quack grass rhizome is actively growing at any one time.  The application of glyphosate will kill that part of the rhizome, but within a few days, a previously dormant part of the rhizome will send up shoots of grass and start spreading in the garden.

Fluzifop is another chemical means of controlling grasses in perennial plantings.  It is marketed as "Grass-B-Gon" and can be used in most perennial plantings to kill grass infestations without harming favorable plants.  The exception to this is "monocot" plants or those plants with grass-like leaves, like daylilies, iris, and lilies.  Grass-B-Gon will damage and may actually kill these plants.  Grass-B-Gon can be used on edibles, like asparagus and rhubarb, but the produce should not be used for one year after the application.  As with glyphosate, you will need multiple applications of fluzifop to completely eradicate quack grass.

You can also dig the quack grass out of the garden, but you really do have to be careful to remove every tiny piece of the fleshy rhizome.  Even the tiniest piece will start an abundance of new quack grass plants.  The rhizomes are a yellowish white color, about 1/8 inch around and they have joints every inch or so.  They are so tough, they can actually grow up through asphalt.

All plants, even ugly ones like quack grass, require photosynthesis to survive.  Cutting all evidence of green growth back to the ground as soon as it appears will weaken the root system over time.  This requires diligent monitoring and quick death to the green growth to prevent it from providing any nutrition to the rhizomes, to eventually kill them.

I will be employing a combination of all these techniques to rid my gardens of this monster.  And I will be doing it next year.  And the year after...  until the quack grass realizes that I am more stubborn than it is.