Yellow spots every july

[Patio]

I live in Seattle, WA. I have a beautiful green yard until around the beginning or middle of July when it warms up. then my yard starts turning yellow in spots. this is the 4th year in a row. warm here is 80-90 degrees. I thought I figured out what fungus it might be, so last year I put Ortho Max lawn and garden insect killer on the yard, as it called for, it ended up getting 4 applications. I thought I would be past the dead yard, but it's back. I water 20 minutes every morning, and fertilize every 2 months

[Blackgoats]

Try this - grab a handful of grass and pull up. If it comes up with easy with little or no roots; you have grubs ! Let me know what your results are.

[Patio]

I grabbed a handful of grass and it came right out with no roots. You might have noticed in my earlier post that last year I applied ortho Max lawn and garden insect killer on my lawn. starting in the summer, then every 6-8 weeks. and ended up with 4 applications of it. I was really hopeful for this year, but had the same thing? am I using the wrong stuff, or is there a better treatment?

[rainbowgardener]

Sounds like you might have grubs, which are the larvae of Japanese beetles and related critters. You won't find them in the soil right now, because this is the time of year when they metamorphose into adults and emerge from the soil, fly around, mate, lay eggs.

Around the beginning of Sept is a good time to apply milky spore powder, which is the spores of a disease that affects only the JB's. You just put it on your soil and it soaks in with the rain and multiplies in your soil. Sept is good, because there will be grubs in your soil, but they will still be pretty close to the surface. You can dig around a little at that time, to be sure you actually have grubs. They are thick white worms that stay curled up in a C shape.

The larvae might not be affected by the insecticide you have been using, because they are under some inches of soil.

[Patio]

You said to apply a milky spore powder in September. I'm not sure what this is? does it have a specific name? I was also wondering if I should stop watering, and fertilizing?

[rainbowgardener]

It is exactly what I said, spores of a bacterial disease that affects grubs.

It is sold as milky spore powder in any garden store, including the big box ones:

https://www.homedepot.com/p/Milky-Spore- ... fj0-0bAiZY

It is great stuff, because multiplies in your soil, so does not have to be reapplied.

Here's more info about it:

https://web.extension.illinois.edu/blmp/ ... 27553.html

Don't stop watering... your grass roots are being eaten, so it needs more water, not less to make up for less root system to absorb water. But I would stop fertilizing. While your grass is struggling, fertilizer is just another stress. It forces leaf growth that the plant doesn't have the root system to support.

[Patio]

Thank You for the advice, I will apply it this september

[Blackgoats]

Here is my suggestion: Bayer Advanced 24 hr Grub Killer Plus. Make sure you get the specific chemical mix with 9.3% Trichlorfon. It works for us.

[rainbowgardener]

But why should you use a potent environmental toxin when milky spore is harmless to everything but the grubs and works well? Triclorfon is an organophosphate. Like other insecticides in that class it bioconcentrates up the food chain. It ends up inthe waterways and is highly toxic to fish and aquatic invertebrates and is highly toxic to birds. Has lots of harmful effects on people to and is readily absorbed through the skin. It is banned in the EU, New Zealand, Brazil and other places.

[Blackgoats]

We always ask "why" when we have no understanding of life different from our view. The danger posed by the grubs is not something one can wait to deter or stop in Sep, it is needed now; much like emergency surgery or even taking any sort of tab or capsule (for headache or more). I don't doubt, deny, or question you, SGTh, on your opinion, just the cavalier attitude this issue can wait for a month or more. Attack it now aggressively, a different approach may be viable later. 'Nough said, or it should be.



"Conservatism: The voice of reason in a liberal world." - There, I said it!

[rainbowgardener]

The reason I said wait is that the grubs are not in your soil right now. They are above ground in the form of Japanese beetles, eating leaves of grape vines and a lot of other stuff. Therefore no damage is currently being done to your grass roots. And therefore treating your soil with grub killer of any sort doesn't help (though the milky spore is still better because it will stay in your soil and multiply).

This is completely separate from how you feel about introducing potent poisons into the environment in order to keep your grass from having yellow spots.

[Patio]

Thank you for the input of both of You two, I will look into both products a little more, and decide on which way to go.

Stay Green

[rainbowgardener]

Thank you for the input of both of You two, I will look into both products a little more, and decide on which way to go.

Stay Green

If you really mean "Stay Green" in an environmental / ecological sense [as opposed to say "grow lots of green plants" or "paint everything green" or even "get lots of dollars" ], then the choice for you should be obvious.

Either way, now is not the time to treat your soil.