How to make lawn greener?

We are planning on putting our house on the market in 3-4 weeks. The large lawn needs some work to improve its looks. The front lawn is thick and free of weeds. But even with frequent watering, it is looking brownish-yellow in a few areas. Maybe it needs some fertilizer. If so, what kind would be best?
Our back lawn is green enough. But in areas that we replanted grass a couple of months ago, a lot of weeds (look like small dandelions) have appeared. Is there some type of treatment that would take care of the weeds quickly?
We live in Western Washington near Olympia. The weather has been very mild with highs in the mid-70s and lows in the mid-50's, partially cloudy with only occasional showers. Thanks for any advice.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'd use ammonium sulfate. Cheap, quick, will give the green color you want. Unless your grass is short of iron, a local nursery should be able to tell you if that's likely.
For the weeds, I'd use a quick acting broadleaf weed killer spray, look for something that promises 24 hour action.
The purists in the group will hate me for giving this advice.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
If you fertilize with magnesium I hear it will create a greener lawn. The center of every chlorophyll is magnesium. Just a thought.
--
Sincerely,
John A. Keslick, Jr.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
get dolomitic lime. get the liquid and spray it on. it has calcium and magnesium. if all else fails.... green paint, I think they got something they use for lawns. Ingrid
On Sun, 12 Aug 2007 20:32:36 -0400, "symplastless"

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Lawn grass should be easy to grow in your climate. Lay down a light top dressing of bagged topsoil and treat with Scotts Turf Builder +2. Mow twice a week with a mulching blade set at 2". Within two weeks you'll have the prettiest lawn in the county.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What species of grasses do you have?. And is your mower blade sharp?

Hawkweeds. Water well, grab and pull. Overseed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.