Question
We just Hydroseeded our yard about 6 weeks ago. We are in Northern California and have many oak trees in our yard. The side of the lawn that is mostly shaded is doing great. The grass has come up fast and very green. The other side that receives the sun is slower growing and has a black mold on it. The owner of the Hydroseeding company told us to buy a product by the name of Four to kill the mold. What is this mold and is this product the only one to use. He said we would have to buy the product from a landscaping supply company so I can only assume it's very strong and/or toxic. Do you have any other suggestions? Thank you.

Answer
Sure would like to know what Grass they used to spray your Soil with, Melissa.  'Fast' growing Grass is usually Rye, but this is growing strong in Shade.  Please find out what Grass they put down -- you will need to know this so that you can do things like mow it perfectly, for example, or i.d. the potential problems that they are most susceptible to.

Black Mold on Grass is descriptive of many things.  There are many ways we have to treat Grass that has fallen prey to Lawn Fungus, but I need to know what you've got to give you a decent IPM schedule.

I hate to do this, but I am giving you the Bayer Products website Fungus I.D.:

www.bayeradvanced.com/disease-identifier.html

I would take a good look at Stripe Smut.  Please confirm or correct, asap.  Thanks for writing.

THE LONG ISLAND GARDENER