Can't really tell if you mowed too much off on one pass, but generally the idea is to mow no more than 1/3 of the grass blade off at one time. So if the grass was up to 9 inches high and you wanted it to be 4 inches, then you would mow twice. Since mowers don't have a height adjustment at 6 inches, then you should use a string trimmer for the first cut. Then a couple days later bring it down to 4 inches.

The previous owners brought in far too much soil. Unless you have a budget to make this perfect, you can leave it alone and deal with the consequences. You might see mud washing out onto the sidewalk and street. Here's what the front part should look like as far as the soil height goes.

That lawn looks artificial to me, but I was there and took the picture, so it's real. They just had a landscaper take away all the excess soil and level it before plugging in the grass.

Yes you have a mix of grasses. Whether they are weeds is in the eye of the beholder. On the plus side they are covering the soil with greenness and filling the soil with valuable roots. They keep the mud off your shoes. If they grow too fast then the lawn can look shaggy before the week is through. If you want to categorize things, there are two kinds of plants: those that look like grass and those that don't. The plants that don't look like grass, for example dandelions, clover, and others can be killed without harming the grass by using a product like Weed-b-Gon. There is a grass killer for grassy weeds, but it will also kill the grass, so there's that. There are some grass killers that are specific to particular grasses, but I'm not up to speed on those.

You can really tune up your lawn by edging it. Many, if not most, people do edging with a string trimmer.

Basics of Lawn Care

After reading numerous books and magazines on lawn care, caring for lawns at seven houses in my life, and reading numerous forums where real people write in to discuss their successes and failures, I have decided to side with the real people and dispense with the book and magazine authors. I don't know what star their planet rotates around but it's not mine. With that in mind, here is the collected wisdom of the Internet savvy homeowners and lawn care professionals summarized in a few words. If you follow the advice here you will have conquered at least 50% of all lawn problems. Once you have these three elements mastered, then you can worry about weeds (if you have any), dog spots, and striping your lawn. But if you are not doing these three things, they will be the first three things suggested for you to correct.

1. Watering

Water deeply and infrequently. Deeply means at least an inch in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. Do not spread this out and water for 10 minutes every day. If your grass looks dry before the month/week is up, water longer next time. If that does not work, then you might have to water more than once per week during the summer's hottest period. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds.

You will have to learn to judge when to water your own lawn. If you live in El Paso your watering will be different than if you live in Vermont. Adjust your watering to your type of grass, temperature, humidity, wind, and soil type. It is worth noting that this technique is used successfully by professionals in Phoenix, so...just sayin.' The other factors make a difference. If you normally water 1 inch per week and you get 1/2 inch of rain, then adjust and water only 1/2 inch that week. You can time your sprinklers by placing several cat food or tuna cans around the yard and timing how long it takes your sprinklers to fill all the cans. Mine takes 8 hours while some high flow systems take 20 minutes. Yours will be in between.

2. Mowing

Every week mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. However, bermuda, centipede, and bent grasses will become the most dense when they are mowed at the lowest setting on your mower. In fact there are special mowers that can mow these grasses down to 1/16 inch. Dense grass shades out weeds, keeps the soil cooler, and uses less water than thin grass. Tall grass can feed the deep roots you developed in #1 above. Tall grass does not grow faster than short grass nor does it look shaggy sooner. Once all your grass is at the same height, tall grass just looks plush.

3. Fertilizing

Fertilize regularly. I fertilize 5 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above. Follow the directions on the bag and do not overdo it (unless you use organics in which case you may overdo it without fear of hurting anything). Regardless of what you see on TV commercials, your first application of chemical fertilizer should go down at the end of spring - Memorial Day is easy to remember. The next app goes down the end of summer (Labor Day). The last app goes down the end of autumn (Thanksgiving or so). The last app should go down after the grass has stopped growing but before the frost hits.

At this point you do not have to worry about weed and feed products - remember at this point you are just trying to grow grass, not perfect it. Besides once you are doing these three things correctly, your weed problems should go away without herbicide. Weed n feed products are universally panned on the lawn forums. Use herbicide in mid April and fertilizer in late May. That will get you there. I might point out that these three elements are in order of importance. You can screw everything up badly by focusing on fertilizer and not getting the watering right.

@dchall_san_antonio Wow, thanks for taking the time to share all this info!  I'm gonna be honest, I don't think I've seen my husband water the grass once. ὣ3 That being said, we do get decent rain,but I imagine our lawn is thirsty for a real watering. He mowed the lawn again recently and took way too much off judging by the tips you gave. Our lawn now has yellow patches all over which I think is either thatch or the grass responding to being stressed out...not 100% sure which. He only mowed one part so I advised him to mow the rest higher next time. Once he's done mowing we'll water the lawn deeply and get on a schedule. I'll try and share updates of how the lawn is looking after we do this.

If you're getting rain, then restart your calendar. If it rained an inch this week, it should not need water for at least a week or 2. There have been years when I did not water the lawn until July because the rain came at all the perfect times.