After the recent deep freeze our area suffered, lawns look dead but are in fact dormant.  Questions about lawn care are surfacing.  Lawns will green-up as temperatures moderate and stay consistently warm.  How well lawns rebound depends on their health and the health of the soil.  Let me lay out some arguments for treating your lawn, and indeed your whole landscape, in an organic way.

Good organic lawn care involves more than fertilizer and avoiding pesticides. It means building up your lawn’s root structure and the soil that supports it so that you achieve a natural balance between beneficial organisms and pests. With organic techniques that balance will last a long time.

Some basic principles to organic lawn care are:

• Aerate– weedy lawns are often the results of poor drainage and compaction, aeration allows air to enter soil assisting in the breakdown of thatch and allows nutrients to easily enter the soil root zone.
• Dethatch – excessive thatch is often caused by over fertilizing with commercial synthetic chemical fertilizers and over watering in the past. Note: Up to a 1/2 inch of thatch can be beneficial.
• Test – have a complete soil analysis done and bring soil to correct balance of nutrients and structure.
• Feed the soil with a balanced organic (slow release) fertilizer and/or compost and
• Mow High. If grass is cut short, shallow roots develop making it difficult for the grass to withstand drought. Also keep mower blade sharp. A dull blade damages the grass each time it is cut.

Thatch is composed of roots, stolons, and rhizomes (runners). Mulching mowers leave the grass clippings on the lawn (adding organic matter & nitrogen) which increases the microbial activity that assists in the breakdown of thatch.  A beneficial layer of thatch helps the grass root zone to retain moisture. 

The key to success in Houston with St. Augustine lawns is to make sure the soil is rich and alive. Commercial synthetic chemical fertilizers and weed & feed formulas kill off the microorganisms in our soil that are needed for good health of plants. Numerous studies have shown that brown patch in grass is a disease caused by fertilization. There is a direct link between brown patch and fertilization with synthetic nitrogen sources during the growing season.  Also, the use of fungicides, bactericides, herbicides, and insecticides destroy the soil’s health even when they are used on surface plants, as rain, dew or watering will wash the chemicals into the soil.

Researchers have discovered a group of fungi that protect lawn grasses from pests. These endophytes are fungi that have a mutually beneficial (symbiotic) association with many species of grasses. An endophyte derives food as well as protection from living between the cells of the turfgrass plant’s roots. This fungus does not harm the host plant but does produce toxins that are released into the leaves and roots of the grass plant. These toxins that are harmless to the grass (and humans) but repel chinch bugs, sod webworms and other surface feeding insects. Studies at Rutgers University and Lofts Seed Inc. have shown that grass with endophytes present is able to withstand drought and weed invasion better.  It has been estimated that there are 930 Billion microorganisms in each pound of soil under healthy turf grass. (Eliot Roberts of the Lawn Institute)                                                                                                                                    

A Cornell University study concluded that mulching mowers provide a convenient and economical solution to the problem of disposing grass cuttings and leaves. The study revealed that over a season the lawn became healthier and with 40% more growth (as compared to a lawn cut with a bagger). Cutting more than 1/3 of the leaf length injures grass, greatly increasing the chances of insects and disease problems.   

So, do you need any more reasons to go organic in your lawn treatments?  I hope not and that you do your plants, yourself, and our environment a favor by adopting organic approaches to your gardening practices.

A caution from many experts warns that after this harsh freeze that we’ve undergone, do not use weed and feed products on your lawns.  Use organic fertilizers only,  as synthetic ones will do further damage to the stressed grass.  If you have thatch buildup, don’t mechanically dethatch St. Augustine grass now.  Instead, give it a haircut or rake out debris, and apply humates. The humates (humus) will break down the thatch without disturbing the stressed grass roots.

Compiled from several sources:
Excerpts from “Texas Organic Gardening Book”, by Howard Garrett
Excerpts from “ACRES, USA” magazine
Excerpts from “Organic Gardening” Magazine, Rodale Research Institute
Excerpts from The Lawn Institute