What type of grass is this taking over my lawn - Ask Extension
I live on the Oregon Coast, and we put down a new lawn via sod 2 summers ago. Over last year this grass has been taking over my lawn. I am unsure if...
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What type of grass is this taking over my lawn #780979
Asked January 29, 2022, 1:58 PM EST
I live on the Oregon Coast, and we put down a new lawn via sod 2 summers ago. Over last year this grass has been taking over my lawn. I am unsure if it is crabgrass or what type of grass this is that is over growing the sod grass. The sod has struggled (thinning) since installation. What suggestions would you have for me when I start to fertilize this spring.
Tillamook County Oregon
Expert Response
Hello,
Can you send a couple close up photos? Pull a clump of grass and bring it inside so you have good light. Get as close as you can while still maintaing good focus so the photo is not blurry. Can you take one photo of the top of the leaf surface and one from the side taken looking at where the leaf originates from the stem. Look up "grass ligule" on google and see the photos showing the ligule. That is what I want you to get a picture of. You can pull the leaf back if you need to get a better look at it for taking the photo.
Thanks. Once I have the photos, I will be able to confirm what I think the grass species is.
Here are a few close ups. I was surprised how easily the clump pulled up! If you need more or different pics let me know. Thank you for your help!
djm
djm
Sent from my iPhone- please excuse the typos.
On Jan 31, 2022, at 9:46 AM, Ask Extension <<personal data hidden>> wrote:
David,
The grass invading your lawn is velvet grass. The scientific name is "Holcus lanatas". It is a common contaminant in Oregon lawns. On a good note, you can selectively remove it by spraying Tenacity herbicide. The area looks small enough, you may be able to spot treat it using a backpack sprayer. If you get the rate correct (4 - 5 fl. oz. per Acre) you will not kill your other grass. One application is usually enough, but you may have to make a second application 4 weeks later. Before you make the application, you may want to spray plain water on payment while walking (and pumping the pressure handle) to see how much water you are spraying per area per a certain amount of time. Measure how many square feet you covered in that time. Then spray the same amount of time into a bucket and calculate the volume. You should end up with gallons of water per 1,000 sq. ft. number (e.g., 0.50 gallons per 1,000 sq. ft. ). This number will allow you to calculate how much herbicide to put in the tank based on the label. If you have a 3 gallon tank and you wanted to spray 3,000 sq. ft., you would fill the tank to 1.5 gallons (3,000 sq. ft. x 0.50 gallons/1,000 sq. ft. = 1.5 gallons. If the rate of Tenacity is 4 fl. oz./Acre, you would apply 2.7 ml (4 fl. oz./Acre x 29.57 ml/fl. oz. divided by 43.56 (43,560 sq. ft./Acre divided by 1,000 sq. ft.) to the 1.5 gallons of water. Note, you can by a small syringe without a needle to measure this small quantity at a local farm supply store or maybe a hardware store. Be sure to read and follow all the label instructions carefully and wear the required personal protective equiment (gloves, shoes, long sleeve shirt and pants, etc.)
Going forward, I would suggest fertilizing more. This will keep your lawn much denser which will slow weed encroachment. One good way to remember when to fertilize is to use the "Holiday plan". Fertilize on Memorial Day, July 4th, Labor Day, and Thanksgiving. I would make one tweak to this schedule which is to move the last application to closer to Halloween. Perennial ryegrass does much better in the winter with 2 applications in the fall. I think it is better if you make the applications in September (labor day) and October, rather than waiting until the end of November.
You should apply 1 lb. of nitrogen per 1,000 sq. ft. with each application. To calculate how much fertilizer you need to apply, divide 1 by the decimal value of the nitrogen percentage shown on the bag (the first number). For example, if you apply Scotts Turf Builder Winter Guard (32-0-10), you would apply 1/0.32 = 3.125 lbs. of fertilizer to 1,000 sq. ft. to get 1 lb. of nitrogen per 1,000 sq. ft.
You can calibrate a spreader to apply the correct amount by building a catch device using a small piece of plastic gutter and 2 end caps which can be purchased from a hardware store. Then attach the catch device to the spreder using a bungie cord. If your spreader is 2' wide, measure a 50' length so your calibration area is 100 sq. ft. Make a pass across the area and weigh how much fertilizer you catch. Multiply how much you catch by 10 (1,000 sq. ft./100 sq. ft.) and you will know how much fertilizer you would apply to 1,000 sq. ft. with that setting. Adjust the setting up or down and repeat until you apply the correct amount. In the example above, you would want to catch 0.3125 lbs. of fertilizer in one pass over 100 sq. ft. (0.3125 lbs. x 16 wt. oz./lb. = 5 wt. oz. of fertilizer.
Finally, if you want to try and prevent further germination of velvet grass and other weeds, you can apply a pre-emergent herbicide twice per year. Here are a couple links to two products that also have fertilizer:
https://www.domyown.com/turf-fertilizer-21010-with-025-dimension-herbicide-50-fortifyn-sgn215-50-lb-p-21455.html
https://www.amleo.com/the-andersons-19-0-6-turf-fertilizer-with-0-21-barricade-pre-emergent-herbicide-50-lb-bag/p/A19NBR50
You would need to accurately calibrate your spreader when you applied this product because if the rate gets too high, it can kill your lawn. You would apply this product in early to mid March and September (before the rains start). It would replace your September fertilizer application and may replace your May application. The other option is to purchase a pre-emergent herbicide without fertilizer (e.g. Barricade G or Dimension G) and apply that seperately from the fertilizer. These products need to be watered in after application if no rain is expected.
If you are uncomfortable making these applications, I would recommend hiring a licensed pesticide applicator. Most larger landscape maintenance companies have one.
One last thing: you mentioned crabgrass. Crabgrass is a warm season annual. It germinates in April, grows all summer and then dies with the first frost. It would not be a contaminant in Oregon lawns in the winter.
Good luck.
The grass invading your lawn is velvet grass. The scientific name is "Holcus lanatas". It is a common contaminant in Oregon lawns. On a good note, you can selectively remove it by spraying Tenacity herbicide. The area looks small enough, you may be able to spot treat it using a backpack sprayer. If you get the rate correct (4 - 5 fl. oz. per Acre) you will not kill your other grass. One application is usually enough, but you may have to make a second application 4 weeks later. Before you make the application, you may want to spray plain water on payment while walking (and pumping the pressure handle) to see how much water you are spraying per area per a certain amount of time. Measure how many square feet you covered in that time. Then spray the same amount of time into a bucket and calculate the volume. You should end up with gallons of water per 1,000 sq. ft. number (e.g., 0.50 gallons per 1,000 sq. ft. ). This number will allow you to calculate how much herbicide to put in the tank based on the label. If you have a 3 gallon tank and you wanted to spray 3,000 sq. ft., you would fill the tank to 1.5 gallons (3,000 sq. ft. x 0.50 gallons/1,000 sq. ft. = 1.5 gallons. If the rate of Tenacity is 4 fl. oz./Acre, you would apply 2.7 ml (4 fl. oz./Acre x 29.57 ml/fl. oz. divided by 43.56 (43,560 sq. ft./Acre divided by 1,000 sq. ft.) to the 1.5 gallons of water. Note, you can by a small syringe without a needle to measure this small quantity at a local farm supply store or maybe a hardware store. Be sure to read and follow all the label instructions carefully and wear the required personal protective equiment (gloves, shoes, long sleeve shirt and pants, etc.)
Going forward, I would suggest fertilizing more. This will keep your lawn much denser which will slow weed encroachment. One good way to remember when to fertilize is to use the "Holiday plan". Fertilize on Memorial Day, July 4th, Labor Day, and Thanksgiving. I would make one tweak to this schedule which is to move the last application to closer to Halloween. Perennial ryegrass does much better in the winter with 2 applications in the fall. I think it is better if you make the applications in September (labor day) and October, rather than waiting until the end of November.
You should apply 1 lb. of nitrogen per 1,000 sq. ft. with each application. To calculate how much fertilizer you need to apply, divide 1 by the decimal value of the nitrogen percentage shown on the bag (the first number). For example, if you apply Scotts Turf Builder Winter Guard (32-0-10), you would apply 1/0.32 = 3.125 lbs. of fertilizer to 1,000 sq. ft. to get 1 lb. of nitrogen per 1,000 sq. ft.
You can calibrate a spreader to apply the correct amount by building a catch device using a small piece of plastic gutter and 2 end caps which can be purchased from a hardware store. Then attach the catch device to the spreder using a bungie cord. If your spreader is 2' wide, measure a 50' length so your calibration area is 100 sq. ft. Make a pass across the area and weigh how much fertilizer you catch. Multiply how much you catch by 10 (1,000 sq. ft./100 sq. ft.) and you will know how much fertilizer you would apply to 1,000 sq. ft. with that setting. Adjust the setting up or down and repeat until you apply the correct amount. In the example above, you would want to catch 0.3125 lbs. of fertilizer in one pass over 100 sq. ft. (0.3125 lbs. x 16 wt. oz./lb. = 5 wt. oz. of fertilizer.
Finally, if you want to try and prevent further germination of velvet grass and other weeds, you can apply a pre-emergent herbicide twice per year. Here are a couple links to two products that also have fertilizer:
https://www.domyown.com/turf-fertilizer-21010-with-025-dimension-herbicide-50-fortifyn-sgn215-50-lb-p-21455.html
https://www.amleo.com/the-andersons-19-0-6-turf-fertilizer-with-0-21-barricade-pre-emergent-herbicide-50-lb-bag/p/A19NBR50
You would need to accurately calibrate your spreader when you applied this product because if the rate gets too high, it can kill your lawn. You would apply this product in early to mid March and September (before the rains start). It would replace your September fertilizer application and may replace your May application. The other option is to purchase a pre-emergent herbicide without fertilizer (e.g. Barricade G or Dimension G) and apply that seperately from the fertilizer. These products need to be watered in after application if no rain is expected.
If you are uncomfortable making these applications, I would recommend hiring a licensed pesticide applicator. Most larger landscape maintenance companies have one.
One last thing: you mentioned crabgrass. Crabgrass is a warm season annual. It germinates in April, grows all summer and then dies with the first frost. It would not be a contaminant in Oregon lawns in the winter.
Good luck.
Wow! This is great information! Thank you for your help.
djm
On Feb 3, 2022, at 10:14 AM, Ask Extension <<personal data hidden>> wrote:
Thank you for your help. As you can see in the attached photo the first dose of Tenacity is working ( applied 4 wk ago). At this point should I re- apply the Tenacity? I will need to overseed this spring, if I reapply the Tenacity or apply a pre-emergent how soon can I put new seed down.
Thank you,
djm
djm
Sent from my iPhone- please excuse the typos.
On Feb 3, 2022, at 4:54 PM, David McDonald <<personal data hidden>> wrote:
Wow! This is great information! Thank you for your help.djmOn Feb 3, 2022, at 10:14 AM, Ask Extension <<personal data hidden>> wrote:
Hello,
Yes, I would make a second application of Tenacity.
Do NOT put down a pre-emergent before you reseed your lawn. The pre-emergent will prevent your new grass seed from germinating. Reseed your lawn and wait a couple months before you apply a pre-emergent.
Good luck.
Yes, I would make a second application of Tenacity.
Do NOT put down a pre-emergent before you reseed your lawn. The pre-emergent will prevent your new grass seed from germinating. Reseed your lawn and wait a couple months before you apply a pre-emergent.
Good luck.
