Grass in my backyard

Asked December 13, 2012, 5:02 PM EST

My back yard has lush green grass from May to October. When it starts to rain and get cold the yard turns into a muddy pit with very little grass. We also have a big walnut tree shading the yard. We would like to see some grass in the winter.I live in NE Portland. Question: Should I re seed in the fall (now) and what kind of seed do I need.

Multnomah County Oregon

1 Response

Thank you for your question to Ask an Expert about your muddy backyard. There are a couple of possibilities. Lawn grass does not grow well in shade. Therefore grass growing in the shade of a large tree is likely to be thin and less healthy than grasses growing in sunny locations. The heavy rains this fall flatten the grass, exposing the now-muddy soil between the blades of grass. To keep the turf as dense and healthy as possible, regular overseeding may be necessary. The ideal time to do this is late summer to early fall (specifically mid-August to mid-September), so it's really too late to seed this year. The second best time to seed is early May to mid-June. OSU's turf expert recommends the following seed mixture for wet/shady sites: 60% fine fescue, 20% perennial ryegrass, and 20% rough bluegrass. Much more detail about lawn renovation and recommended seeds can be found in the following OSU publication:

Practical Lawn Establishment and Renovatiotion
http://extension.oregonstate.edu/catalog/pdf/ec/ec1550.pdf

Another possibility is that you have a drainage problem. Here is some information about some causes and solutions to landscape drainage problems:

http://extension.oregonstate.edu/gardening/solutions-landscape-drainage-problems

Hope this information helps.