Probably the most commercialized aspect of gardening is lawn care. I believe its based more on profits than plant biology. Look at the number of commercials and amount of advertising devote to having a green lawn. Maintaining a lawn organically is easier and less expensive. An organic lawn also allows you to use your clippings in your compost pile and as a mulch around fruit trees. It is perfectly safe at all times for kids, grandkids, pets, and yourself to play on, lay on, and enjoy.
Here's my routine:
Early Spring (when forsythia blooms) apply an organic fertilizer which usually is composed of various meals with bone meal the most abundant. Look for one that has corn gluten which is a pre-emergent weed control. (Prevents weeds from sprouting) I use Gardens Alive Wow Supreme.
If you lawn has an extreme weed problem apply again one month later.
To get rid of existing weeds use any organic herbicide that has d-limenol and/or clove. These are essential oils. The d-limenol is a citrus oil. They burn what ever plant it is sprayed on including morning glory so only spot spray your dandelions and weeds. Spray any weed that pops up. Be diligent in early spring. By summer very few weeds appear, and you are just enjoying your lawn.
Early fall, September, I fertilize again with a dry organic lawn fertilizer. I use WOW supreme but you can use one without a pre-emergent weed control.
You can reseed bare areas and add compost if needed. Fish emulsion will always help spots that are struggling.
I have never aerated my lawn. You only need to aerate if thatch is a problem.
Keep the lawn mowed regularly.
Watering depends on your soil type and the type of lawn you have as well as your watering system. There are also conditions created by your house and the sun that may effect how often and long you water. I have west facing second story windows that reflect sunlight and almost burn the grass. The type of sprinklers and their output will also effect watering. I have Kentucky Bluegrass and a sandy loam soil. In spring I water as needed. In summer the sprinklers come on everyday for 15 minutes. You can always cut back the water, and if you lawn complains increase the time.
Be sure to choose the right type of lawn for your purposes and concerns. We have a green zone all around our house because we have frequent wildfires and this acts as a buffer zone. Different varieties feel different, grow different, have different water requirements, different hardiness and green up at different times and rates. So do some research so you are happy with your choice.
Confession! I have always followed the routine I shared with you. There is no need for an expensive 4 step program. The lawn has been the pride and joy of my two youngest sons, Blake and Tyler, that have faithful cared for it for while growing up. They are both in college but when they come home they make sure the lawn looks great!