Hi Jeff -

Thanks for contacting us. Below are some questions that would affect our answer.  Most homeowners contacting us have bluegrass lawn problems with random dry areas that struggle to grow grass. If this is not your situation please write back - otherwise please see the information below.

• Is yours a bluegrass lawn, and have the seeds and sod you have put down in the past also been bluegrass?
• What % of your yard is affected?  Where is the area located (under an established tree, in sun or shade, etc.)?
• What is your irrigation routine for your lawn - i.e. do you have an in-ground irrigation system or do you use hoses?  How often and for how long do you water each section or zone of the lawn?

There are a number of factors that affect new grass growth in an established yard. For starters it is highly important that the area is properly prepared before laying seed or sod.  New seed/sod should be hand watered at least once daily for and twice daily during dry and/or hot weather. This is in addition to your normal watering schedule for other parts of your lawn.  The newly seeded or sodded areas should appear moist at all times until new growth is seen.  Extra water should be continued fall to spring if there is not sufficient moisture from rain or snow.

It can take 2-3 years of careful attention to the new area before the new grass can be treated like the rest of your lawn.  Other factors that could affect grass health include heavy traffic, tree roots under the problem area, and/or damage from garden chemicals (herbicides, fertilizer, insecticides) used on nearby areas or accidentally applied to the problem area.  

I'm attaching three fact sheets - first one is on renovating a home lawn: https://extension.colostate.edu/docs/pubs/garden/07241.pdf.  Please note: use this method on the problem areas only, and do not do steps 1 and 2 (on killing the existing lawn).

The second fact sheet is about general lawn care and irrigation: https://extension.colostate.edu/docs/pubs/garden/07202.pdf

Final fact sheet is about lawn irrigation: https://extension.colostate.edu/docs/pubs/garden/07199.pdf

I hope you find this information helpful.  If you have additional questions or concerns, please let us know.

Colorado Master Gardener Clinician Annette