Question
Hi,
I am sorry, for some reason I was thinking you were local.  I live in Peoria, Arizona  85382.  I also noticed yesterday that there appears to be growing mold on the ground.  I never seen that before.
Thank you,
Shirley
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Followup To
Question -
Hi,
I live by 67 ave& Greenway.  When I moved in the lot was smooth and all dirt.  Then the rain came.  I now have almost a solid green yard but it is all various types of weed with no grass.  I tried digging and pulling them but they are growing faster than I can keep up.  
What is the least expensive way to get rid of these weeds so I can start some grass.  I thought of weed killer but I am not sure if it will also kill the grass later.
Please help
Shirley
Answer -
Unfortuneately Shirley I handle questions from throughout the United States. I don't know where 67 ave & Greenway is. Please give me your city or zip code and I will be better able to give you some advice.
Waiting to hear from you.
Floyd McMahon

Answer
Hi Shirley:

I think that is very ironic. I live in Peoria Illinois. Talk about a coincidence!
I am giving you a web site that you can "copy", "paste" and hit "GO" in your browser.
This site is from the Arizona Master Gardeners Manual about lawns. I am sure you will want to book mark it for future reference.

http://ag.arizona.edu/pubs/garden/mg/lawns/index.html

It sounds as if you are in need of lawn renovation.  I would strongly consider killing all the weeds and what remaining grass you have by an application of  glyphosate (Round Up). Follow directions on the label. Keep in mind the weed species needs to be actively growing to be controlled by glyphosate. Allow 10 to 14 days to determine if weeds have been completely controlled then you could plant grass seed with no problem. If you have a lot of shaded areas consider using bark mulch or ground cover instead of grass in those areas.
Think of renovation as fitting one of three levels:
1. Overseeding with little additional work.
2. Overseeding with significant work, but allowing existing grass to remain.
3. Completely removing the existing lawn and starting over.
The decision of which level to choose is based on how bad the lawn looks and what caused the problem. From the description you have provided I would consider option #3
One of the first steps in successful preventive programs is to seed or sod a properly adapted turfgrass species in the lawn (See the Web Site above). Following establishment, adequate fertilization programs and cultural practices facilitating the maintenance of a dense canopy including proper mowing practices, good watering practices, and insect and disease control programs are important.
If you choose to re-seed or sod thoroughly work the soil to a depth of 6 inches. Add amendments such as compost, rotted manure, organic topsoil, peat, etc.
After your grass is up and growing cut it to a maximum height recommended for type of grass you have planted (See the Web Site above).. Cut it frequently and remove no more than 1/3 of the grass blade at each mowing.
Weed control after renovation involves control of annual and perennial weeds.
Annual grass weeds are grass weeds that germinate from seed, grow to maturity, produce seed and die within a 12 month period. A high quality lawn will develop a highly competitive canopy which will shade the soil surface and discourage the germination and establishment of seedling annual grass weeds. Most annual grass weed seeds germinate in the top 1/2 inch of the soil.
If you cannot satisfactorily address the control of annual grass weeds in a preventive manner with strictly cultural controls, the next best way to stop annual grass weeds from establishing in their lawns is through the use of preemergent herbicides. Preemergent herbicides are chemicals that prevent the germinating weeds from establishing in the lawn.  Lawns with thin stands of grass that do not provide 100 percent cover may require yearly applications of a preemergent herbicide.
Preemergent herbicides are generally only effective if applied before the annual grass weeds emerge. Herbicide applications should be completed and the herbicide watered-in at least 7 days prior to the initial germination date to allow time for the herbicide barrier to be established in the soil.
Perennial grassy weeds are considered to be the most difficult weed problems to deal with in lawns. Control options are limited because the weed species are very similar to the lawn species.
One way to distinguish perennial grasses from annuals is the time of the year established plants are present. Perennials will appear as established green grasses early in spring; whereas most annual grasses don't appear until late spring or early summer. Likewise, most annuals die off in the fall, but perennials do not.
I hope I haven't given you so much information that you become discouraged. Once you get that great looking lawn it will be well worth all the initial work and expense.
Have a good lawn!

Floyd McMahon