Winter overseeding a bermudagrass lawn with perennial ryegrass (PRG) is something that has always piqued my interest, so now that I have a proper irrigation system I have decided to give it a shot. Not wanting to bite off more than I can chew, I decided my 2,000 ft2 back yard would be a nice place to experiment this year... that way if it turns into an epic failure I will be the only one who has to look at it 
. I will also be able to compare the spring transition to my non-overseeded front lawn.
I started by reading everything I could get my hands on about the process, and I also reached out to a local turfgrass science professor to get any regional-specific advice he had. Turns out he overseeds his own lawn with PRG each fall, and had this to offer:
One of the things that concerned me was the spring transition back to bermuda, but he said it would be a snap if I spray the PRG with MSM herbicide once the bermuda is greening up in the spring. He said the MSM is slow acting, so the transition is gradual, and would help me avoid a completely brown lawn. I think Celsius and/or Certainty would probably work just as well, but I have some time to make that decision.
For seed I went with Champion GQ from Seed Research of Oregon. It's easy to get lost in all the different varieties/blends available, so I just went with this because it appeared to be a decent choice for overseeding bermuda and it was on sale at Hancock Seed. If I was establishing a new cool season lawn, Iprobably would have spent more time on this, but I will just be killing it in the spring. :lol:
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The recommended winter overseed rates on the Champion GQ specification sheet are as follows - note that these rates are significantly higher than the rates for establishing a new cool season lawn:
These tiered rates appear to be based on density requirements - the lower the HOC, the more density you need. I plan to mow the PRG around 0.75", so I will be using the overseed rate for golf tees and fairways. I will adjust my HOC as necessary, but my thought is if my dormant bermuda is around 0.5", I will want to mow the PRG a little higher to drown out the brown grass.
After reading Pete's Renovation thread, I decided to order a packet of Soil Moist Seed Coat. I'm not overly concerned about keeping the ground moist in the small area I'm working with, but decided it would be cheap insurance. :thumbup:
Prior to overseeding, I plan to do a light verticut and slightly reduce my HOC in an effort to open up the dense bermuda canopy a little. I think this will make it a little easier get the seed in contact with the ground. Alternatively, I read that this is also a good time to core aerate if you wanted to.
Being a big fan of Plant Growth Regulator (PGR) and its many benefits, I had noticed the label specifically addresses using it to slow bermuda growth prior to overseeding in the fall to enhance establishment of the cool season grass, so I will definitely be timing my upcoming PGR applications accordingly:
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I will also not be making any additional fertilizer apps to the back yard before overseeding, and most importantly NO fall pre-emergent app, as it would prevent germination of the PRG.
I have some scheduling conflicts in late September that will require me to be away from home, and I want to make sure I am close during the twice a day watering period, so depending on the rain forecast my tentative plan is to overseed sometime between Sept 16-20. The average highs/lows on those dates for my location are 84°/61°F. If that doesn't work out, I will likely defer to the window of Sept 30 - Oct 3. Average highs/lows on those dates look more like 80°/56°F.
I have about month to work out the final details, but I'm really excited to see how this goes! With any luck, it won't just be the Aussies posting pictures of their warm season lawns on TLF this winter! :thumbup:
. I will also be able to compare the spring transition to my non-overseeded front lawn.The Plan
I started by reading everything I could get my hands on about the process, and I also reached out to a local turfgrass science professor to get any regional-specific advice he had. Turns out he overseeds his own lawn with PRG each fall, and had this to offer:
- Seed in late September at a rate of about 15lbs per thousand (more on this below).
- Use a drop spreader in multiple directions to ensure uniform coverage, then go over the lawn lightly with a leaf rake to knock the seed down to the soil surface.
- After seeding it is extremely important to keep the surface soil moist. Irrigate 0.1" mid morning and again mid afternoon.
- Once the seed has germinated (usually 4-7 days) you can irrigate once a day, but heavier (0.15 - 0.2").
- Apply 2 lbs of N to the lawn 2-4 weeks after germination and you will be all set.
One of the things that concerned me was the spring transition back to bermuda, but he said it would be a snap if I spray the PRG with MSM herbicide once the bermuda is greening up in the spring. He said the MSM is slow acting, so the transition is gradual, and would help me avoid a completely brown lawn. I think Celsius and/or Certainty would probably work just as well, but I have some time to make that decision.
The Seed
For seed I went with Champion GQ from Seed Research of Oregon. It's easy to get lost in all the different varieties/blends available, so I just went with this because it appeared to be a decent choice for overseeding bermuda and it was on sale at Hancock Seed. If I was establishing a new cool season lawn, I
The recommended winter overseed rates on the Champion GQ specification sheet are as follows - note that these rates are significantly higher than the rates for establishing a new cool season lawn:
- Golf greens: 30 lbs per thousand
- Golf fairways and tees: 10-16 lbs per thousand
- Sports fields and golf roughs: 6-10 lbs per thousand
These tiered rates appear to be based on density requirements - the lower the HOC, the more density you need. I plan to mow the PRG around 0.75", so I will be using the overseed rate for golf tees and fairways. I will adjust my HOC as necessary, but my thought is if my dormant bermuda is around 0.5", I will want to mow the PRG a little higher to drown out the brown grass.
After reading Pete's Renovation thread, I decided to order a packet of Soil Moist Seed Coat. I'm not overly concerned about keeping the ground moist in the small area I'm working with, but decided it would be cheap insurance. :thumbup:
The Prep
Prior to overseeding, I plan to do a light verticut and slightly reduce my HOC in an effort to open up the dense bermuda canopy a little. I think this will make it a little easier get the seed in contact with the ground. Alternatively, I read that this is also a good time to core aerate if you wanted to.
Being a big fan of Plant Growth Regulator (PGR) and its many benefits, I had noticed the label specifically addresses using it to slow bermuda growth prior to overseeding in the fall to enhance establishment of the cool season grass, so I will definitely be timing my upcoming PGR applications accordingly:
I will also not be making any additional fertilizer apps to the back yard before overseeding, and most importantly NO fall pre-emergent app, as it would prevent germination of the PRG.
The Calendar
I have some scheduling conflicts in late September that will require me to be away from home, and I want to make sure I am close during the twice a day watering period, so depending on the rain forecast my tentative plan is to overseed sometime between Sept 16-20. The average highs/lows on those dates for my location are 84°/61°F. If that doesn't work out, I will likely defer to the window of Sept 30 - Oct 3. Average highs/lows on those dates look more like 80°/56°F.
I have about month to work out the final details, but I'm really excited to see how this goes! With any luck, it won't just be the Aussies posting pictures of their warm season lawns on TLF this winter! :thumbup:
