INVASIVE GRASS VS. FLOWERING PLANTINGS - Ask Extension
I HAVE A FLOWER BED (FOR NATIVES) SURROUNDED BY A GRASS LAWN (WAS HERE BEFORE I BOUGHT THE HOUSE). THE GRASS INVADES THE FLOWER BED. DIGGING/PULLING...
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INVASIVE GRASS VS. FLOWERING PLANTINGS #865439
Asked April 22, 2024, 1:28 PM EDT
I HAVE A FLOWER BED (FOR NATIVES) SURROUNDED BY A GRASS LAWN (WAS HERE BEFORE I BOUGHT THE HOUSE). THE GRASS INVADES THE FLOWER BED. DIGGING/PULLING THE GRASS SEEMS TO ONLY ENCOURAGE NEW GROWTH (SINCE IT SPREADS VIA UNDERGROUND ROOTS) WHILE EXTENSIVELY DAMAGING THE FLOWERS. IS THERE ANY NON-CHEMICAL OR (ALAS) CHEMICAL SOLUTION THAT IS SELECTIVE FOR KILLING THE GRASS WITHOUT KILLING THE FLOWERING PLANTS ALONG WITH THE GRASS?
Deschutes County Oregon
Expert Response
Hi Angus:
This is a difficult problem to solve. It will be an ongoing project for you.
First, may I suggest a good deep lawn edging that makes a solid break between the grass and lawn. This will keep the creeping grass to a minimum.
If the bed is really overgrown, you may need to remove the plants and tackle the grass on a larger scale. One method is to cover the area with cardboard, then a thick layer of mulch. Water throughly. The lack of sunlight will kill the grass, the cardboard will decompose and you may start fresh with your grassless flower bed. Another method is to remove the plants, dig up the bed and remove the grass by hand.
If the problem is not overwhelming, you may want to pull by hand. The spring, before everything start to grow is a great time to do this. The grass seems to appear first and you can get a good handle on it. You will never eliminate it completely. Just add this chore to your yearly list of to dos!
As a last resort, use glyphosate (roundup) to kill the grass. It will kill everything else, so you would need to be extremely careful. I've seen suggestions to "paint" it on the grass as to prevent overspray in tight areas.
I'll attach an article on the cardboard method if you would like additional information.
Break Up Your Lawn Using Cardboard
Thank you for your question,
This is a difficult problem to solve. It will be an ongoing project for you.
First, may I suggest a good deep lawn edging that makes a solid break between the grass and lawn. This will keep the creeping grass to a minimum.
If the bed is really overgrown, you may need to remove the plants and tackle the grass on a larger scale. One method is to cover the area with cardboard, then a thick layer of mulch. Water throughly. The lack of sunlight will kill the grass, the cardboard will decompose and you may start fresh with your grassless flower bed. Another method is to remove the plants, dig up the bed and remove the grass by hand.
If the problem is not overwhelming, you may want to pull by hand. The spring, before everything start to grow is a great time to do this. The grass seems to appear first and you can get a good handle on it. You will never eliminate it completely. Just add this chore to your yearly list of to dos!
As a last resort, use glyphosate (roundup) to kill the grass. It will kill everything else, so you would need to be extremely careful. I've seen suggestions to "paint" it on the grass as to prevent overspray in tight areas.
I'll attach an article on the cardboard method if you would like additional information.
Break Up Your Lawn Using Cardboard
Thank you for your question,
Christi,
‘
Thanks very much for getting back to me, even if it is with the answer I expected/feared.
Your grass-kill exercise is pretty much how I created this “flower” bed in the first place (but with newspaper and mulch to kill the pre-existing lawn). I should have thought at the time about grass invasions and put a barrier in place but didn’t.
Pulling the grass can be an ok zen moment but one usually shattered by the realization that I’ll never get all the little nubs of root and the grass will be back on schedule.
Killing everything and starting over is too drastic for me to contemplate, like Sisyphus forever rolling the wad of grass up his hill.
So maybe I’ll just have to make my peace with a kind of grass + native flowers prairie effect.
Appreciate your thoughts, notwithstanding.
Angus Duncan
Angus Duncan
PNW Consultant
Natural Resources Defense Council
2381 NW Johnson St
Portland, OR 97210
503.248.7695
On Apr 24, 2024, at 9:29 AM, Ask Extension <<personal data hidden>> wrote:
Angus:
The grass invasion is a battle I face constantly in my own garden. You are correct, you will never eliminate it. You just have to decide how much you can live with and go from there.
All the best,
The grass invasion is a battle I face constantly in my own garden. You are correct, you will never eliminate it. You just have to decide how much you can live with and go from there.
All the best,
