With the recent heavy rains and slightly cooler temperatures no doubt people are thinking about overseeding their California and Arizona lawns. While the calendar says September 18th and you will surely see people overseeding, I suggest you wait a few weeks. Follow my California and Arizona sod tips for a beautiful lawn. Overseeding does not need to be a one day process. You can begin the process a little early. Then, when temperatures are in the 60’s at night, you will just need to give your lawn one last haircut, drop the seed and begin watering.

Preparing to Overseed

Prepping for overseed is often a large ordeal. By starting the process gradually you can eliminate the headaches associated with trying to do it all in one afternoon. I want to reiterate something I have been saying for the past few years. The height of the grass is not associated with a quality overseed. In other words scalping the grass down to the dirt does not guarantee good results. Opening up the turf canopy does.

The shorter you mow your lawn the tighter the leaf blades become. This makes it harder to get the ryegrass seed into the plant. If the seed is lying on the surface it will be slow to germinate and much of the seed will be lost. The seed needs a base to grow out of. Getting inside the grass plant allows for perfect moisture, heat, and a solid growing medium. By looking at my last statement you can now understand why I say without a good warm season grass base (used on popular California and Arizona lawns) you will most likely have a poor ryegrass season. The seed will establish much faster inside a healthy grass stand than it will on bare dirt.

Arizona Sod

Preparing Your Lawn

Since we’re still a few weeks out of actually dropping seed, I want to discuss getting your lawn ready. Now is a great time to let your lawn grow up about 30% in order to provide more leaf density. Another bonus of maintaining your lawn at a taller height is that it will use less water. When you scalp your lawn it will leave plenty of healthy new leaves for the spring. If you continue to maintain your grass at its normal height and then scalp it to the ground, you risk serious injury to your warm season grass for next year.

When you’re about 3-4 days out from overseeding I would suggest renting a verticutter/dethatcher and opening up the turf canopy. This will eliminate all of the dead material between the leaves and will allow the seed to drop into the plant easier. You can wait to verticut until the day you seed or you can get it done a little early. If you go early make sure you verticut in a few directions so when you scalp for overseed the canopy is still open.

With the height of cut a little higher this will allow you to scalp your lawn to the height you have maintained it at all summer. If you keep your lawn at 1” you will need to mow it down to a ½” which most mowers are unable to do successfully. Most rotary mowers can go to ¾”at the very lowest setting. My recommendation is going to 1.25” and then scalping to ¾” versus maintaining at 1” and trying to scalp to a ½”.

Remember the lower you mow, the tighter the grass becomes. Every time you make the grass canopy tighter you will need to come back through and verticut to open the grass plant back up. It is much easier to open the turf canopy on slightly longer grass than it is on ½” turf.

As you make your way through the hardware stores this weekend, you will start to see ryegrass seed all over the shelves. It is extremely important to be vigilant when you pick up a bag of seed. Remember not all seed is created equal.

Tips for Purchasing Seed

  1. I highly suggest you only use perennial ryegrass. While it seems like the name annual ryegrass makes sense it does not have the vigor, color, or density of perennial ryegrass.
  2. You will seed your lawn at the rate of 10 pounds of seed per 1000 SF. With that being said, you will see bags all over the store that say this bag covers 10,000 SF or more. How is that possible if the bag is only 50 pounds? On the east coast where these bags were likely produced they overseed in the spring or fall to increase turf coverage. They don’t change out their lawn for the season. Therefore, to overseed there you only need 3-5 pounds per 1000 SF. Technically the bag is correct that it covers 10,000 SF for overseeding but not California and Arizona sod overseeding.
  3. Germination Rate – The germination rate will tell you how much of the seed is viable. If you pick up a bag with a 60% germination rate then you need 40% more seed to cover. You want to find a bag with over 85% germination.
  4. Weed Seed – This number should be zero. Any weed seed or inert matter is going to wreak havoc on your overseeded turf.
  5. Often times blended ryegrass seeds are cheaper because they put different grades of seed in the bag. Our seeds are a single source sod quality seed which brings the price up slightly from other brands. Remember ryegrass seed is priced by germination, weed seed, and quality of the seed. Therefore if you find a deal on seed it’s not always your best bet.

So what do you need for overseeding?

  1. First pick up a high quality perennial ryegrass seed. Again you want to apply 8-10 pounds per 1000 SF of lawn area. There is no need to put anymore seed.
  2. Starter Fertilizer – When you pick up your seed why not pick up the fertilizer? We sell our own starter fertilizer called Soil Burst 4-4-2 that can be applied with the seed. Or pick up 6-20-20, 16-20-0, or 11-52-0 depending on what your stores carry. You can buy the Soil Burst from us online at westcoastturf.com or over the phone at 1-888-893-TURF (8873).
  3. Second Fertilizer – If you use the 5-15-10 then this will also work as a second application for the new seed or you can use 21-7-14, 11-52-0, or 6-20-20.
  4. All of your sprinklers should be working and properly adjusted. Check all of the nozzles after you scalp for any chips or dings that the mower may have caused by cutting shorter.
  5. Verticut/dethatch

I made a short video (below) on the entire overseed operation. If you have any questions please feel free to reach out to me. You can click “Ask Jay” on the upper right corner of this page,  or call our hotline at 888-893-TURF (8873).  Check back for year-round California and Arizona sod tips.

Happy overseeding!