Most turf grasses in the PNW will be blends of various cool weather grass seeds, however sod farms seem to prefer monocultures and often go with a single type. Because many of these grasses look virtually indistinguishable from each other, best to go back to the source and ask where you purchased the sod. Because our cool season grasses want to go dormant in summer, I tend to recommend fall as the best time to overseed or do much remedial lawn care. What you can do now is to aerate the soil, using a plug or core aerator. Aerating is one of the best things you can do for a lawn or the ideal first step in lawn care prep. After aerating, spread a thin layer of compost, just a half inch or so. Water as necessary but not too frequently and deeply when you do. In my Puget Sound climate, once every week to 10 days is usually sufficient through summer provided the water penetrates down 6-8 inches. Weed manually as required. Then in fall you can overseed. Again, cover with a thin layer of compost (better than peat or topsoil) and keep moist until full germination, usually about 10-14 days. Mow when the new grass is at least 2.5 inches tall. And you can still fertilize before winter. If you overseed in September, you should be able to fertilize in mid to late October. Of any time of year, the fall fertilizing is the most beneficial in our region. And opt for an organic product if you can.

teeka - Go ahead and spray, you won't harm the bamboo if you're carefull. Don't spray on a windy day, keep the sprayer on a tight stream, and stay low to the grass.

It's brought in by birds - pooping the seeds - so it will be a never-ending problem. Just pull it when you see it.

It is unfortunate that misinformation continues to be repeated about glyphosate. Denmark has not banned glyphosate, nor have "many European countries". Denmark at one point thought that some of the monitoring they were doing showed that glyphosate could move into agricultural field drainage water in autumn but once they looked at their data and related it to the methodology they used, they enacted no ban whatsoever. As the Danish Environmental Protection Agency specifically stated: http://www.egeis.org/home/main/Evaluation-GlyphosateDEPA.PDF "Against this background, the Danish Environmental Protection Agency believes that no unacceptable risk of pollution of the groundwater is associated with the currently approved agricultural use of glyphosate. The Agency thus does not consider that the updated state of our knowledge provides any technical grounds for the imposition of restrictions on the autumn application of glyphosate." Used properly, glyphosate will not pollute drinking water nor will it have adverse effects on humans. Once applied, it binds tightly to soil particles and is not herbicidally active. If it is applied to hard surfaces such as sidewalks it can move offsite of course. It can also move if there is active soil erosion carrying soil off site. It is of very low toxicity, and breaks down completely into natural constituents over time. It is of equal or lower toxicity than most household products such as detergent, soaps, shampoos, cleaners etc. and far less toxic than some of the "alternatives" often discussed such as bleach, kerosene, high strength vinegars and so on. There is so much misinformation being repeated on the web that it is difficult to get reliable information. This link provides an published overview of the available literature. Regulatory Toxicology and Pharmacology Volume 31, Issue 2, April 2000, Pages 117-165 Safety Evaluation and Risk Assessment of the Herbicide Roundup and Its Active Ingredient, Glyphosate, for Humans http://cat.inist.fr/?aModele=afficheN&cpsidt=1401479