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Phythium Blight or Fertilizer Burn?

Wondering what you guys think? Is this a burn either from the sun or fertilizer or does this look like a fungus like Phythium Blight?

I just had my yard hydroseeded in the spring. I watered appropriately and the grass came right up nice and soft and green. After it was in and growing nicely I mowed the lawn and my husband applied a starter fertilizer. I didn't realize the hydro seeding had fertilizer mixed in already. A few days went by and we had a scorcher weekend where I wasn't home and wasn't watering. Then I noticed some brown spots that I thought were burns to the immature grass. However, it seems like it's spreading/getting worse and it was dead almost overnight. I notice it all around the back of the house and in some spots in the middle of the lawn surrounded by healthy green grass. The way the burns run are opposit the way The dry fertilizer was spread with the spreader so I'm wondering if it's infact a fungus like Phythium Blight. I don't have a lot of experience in treating something like this. Does anyone have any insight based off of these pictures? Thanks in advance.

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Joined: Thu May 22, 2014 1:26 am
Location: Upstate, SC

Re: Phythium Blight or Fertilizer Burn?

I don't think this is blight.

It does look like burn to me. New tender grass is a lot more sensitive to heat and drought than mature grass. Generally, when plants are already stressed by heat, and then ferts are added, it tends to exacerbate the stress instead of making them stronger. Ferts stimulate growth which requires more water.

I don't know that this can be fixed aside from diluting the ferts. Make sure the lawn is getting watered at the appropriate levels.
Upstate, SC
USDA Zone 7b/ Sunset Zone 31

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Location: hawaii, zone 12a 587 ft elev.

Re: Phythium Blight or Fertilizer Burn?

Mow at the recommended height for your type of grass. In summer grass can be mowed about a half an inch higher. You need to put at least 1-2 inches of water or rain on the lawn every week. On the other hand hydroseeded lawns don't have any sod attached to it, so they can easily be drowned by too much water which would end up looking like a sparse lawn.

I agree with not fetilizing grass when it is stressed, it just makes it try to grow and need more water.

There are some yellow patches in the lawn, you may have to check for grubs and chewing insects too that not only eat the grass but the roots. too.
Happy gardening in Hawaii. Gardens are where people grow.

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