I think one of the reasons folks are reluctant to switch to organic lawn care is that they think it's going to be complicated. Or more expensive. It's not.

Really, the only difference is that one stops using synthetic chemical products to tend to your lawn -- all other good lawn maintenance practices remain the same.

1) Focus on the soil. Aerate regularly to reduce compaction and topdress with a thin layer of compost to renew organic matter. I recommend this be done once a year, fall being my preferred season.

2) Mow high and often, removing no more than 1/3 of the blades at any time. Most cool season lawns should be maintained at about 3". This length will shade out weeds and conserve soil moisture, reducing the need for frequent irrigation.

3) Grasscycle -- use a mulching mower. Studies have shown that grasscycling or returning the clippings to the lawn does not contribute to thatch build-up....quite the opposite, it reduces it. A mulching mower (most lawn mowers can be retrofitted with a mulching blade if not present) minces up the clippings into a very fine consistency that filters down through the blades to nourish the soil and thus feed the lawn. This can reduce your fertilizing needs as much as 85%.

4) Water infrequently but deeply. Most lawns require only an inch of water a week and this should be applied in only one or two applications so reset any automatic sprinkler systems to reflect this pattern. Less frequent but longer watering periods encourages deeper water penetration into the soil profile and the grass roots will follow. Deeper roots increase drought tolerance and actually decreases the needed amount of supplemental irrigation.

5) Overseed as necessary to thicken the lawn. A dense, thick lawn will successfully outcompete weed development. Remove any existing weeds manually or exercise a bit of tolerance. A completely weed-free lawn is virtually impossible to achieve but the healthier your lawn is (by following the above practices), the less likely weeds will be an issue.

6) Fertilize when necessary with a natural product - seed meals (soy, cottonseed, corn gluten), alfalfa meal, or packaged organic lawn fertilizers. These are naturally slow release products so don't expect the immediate greening you see with the chemical products. The slow release also means they don't need to be applied often, once a season is usually sufficient. Fall is the best time, especially with cool season grasses. This helps to build nutrient reserves to take your lawn through winter and give it a good start in spring. Cool season lawns want to go dormant in summer so fertilizing much or too late in spring can be stressful and counterproductive so use a very light hand in spring.

Warm season grasses can tolerate a spring fert application easier.

And it may take a season or two to notice a significant difference but be patient........it will happen. And do follow the basic lawn maintenance practices followed above - if you adopt these religiously, you will find the need to apply any fertilizer to your lawn is greatly reduced. I haven't needed to apply any fertilizer in years by just adhering to these practices and grasscycling with nearly every mowing.

See Link

Here is a link that might be useful: Organic Lawn FAQ

The soil Biology Primer mentioned in Dave's FAQ list can be found at the link below.
Aeration of soil may be necessary if that soil lacks adequate amounts of organic matter but once the levels of OM are there aeration will no longer be necessary. Aeration also should only be necessary in soils of clay since most sandy soils have large enough pore spaces to allow air movement into those soils.

Here is a link that might be useful: Soil Biology Primer

Aeration of soil may be necessary if that soil lacks adequate amounts of organic matter but once the levels of OM are there aeration will no longer be necessary. Aeration also should only be necessary in soils of clay since most sandy soils have large enough pore spaces to allow air movement into those soils.

This is not at all true. Any soil under turf grasses is prone to compaction. It happens due to rainfall and irrigation and from lawns being walked on, played on, mowed, raked,etc. Porosity declines under these conditions and OM is not omnipresent - it needs to be routinely replaced.

Virtually any site that advocates organic lawn care will recommend regular aeration

Some people simply do not understand the role that organic matter plays in the soil as well as what the Soil Food Web does. Ma Nature does not send out machines to aerate the soil she maintains, that is done with the addition of organic matter that feeds the Soil Food Web that aerates the soil.

And some people simply do not understand that a non-natural, cultivated garden setting - like a lawn - cannot be equated to a situation where Ma Nature is not impeded by human intervention. If you walk on the soil (essentially what you are doing with a lawn), push heavy equipment across it, bombard it constantly with rainfall and irrigation, soil compacts. And you do understand what compaction does to soil structure and the impact that has on the soil biology, don't you?? Any organic matter simply placed on the top - especially when it doesn't come into direct contact with the soil itself (the turf grass and its roots being in the way) - is not going to be the slightest bit effective. You need to reduce or eliminate that compaction and the only way that can be done is by altering the soil structure by increasing porosity via aeration and the insertion of organic matter directly into the soil profile to maintain the porosity until the biology comes back into balance and takes over. For the short period of time until it all happens again.

This is why they tell you not to walk on or work wet soil - it damages the structure and results in compaction. A difficult situation to recitify and one that is NOT addressed simply by applying OM to the soil surface. And regularly irrigated lawns are nothing more than wet soil.

I understand this concept may be difficult to those with a very simplistic approach to soil science and lawn care to absorb. Judging by the responses, it sure seems that way. Just putting it out there for clarification and to allay the misinformation that seems to get spread here so frequently.