Many regions have soil types which have a heavy silt or clay content which often results in the soil constantly retaining too much water at all times. It’s the very fine particles within these soil types which causes them to stick so closely together, and thus preventing the free flowing of water through the earth. As a result of this, the Saint Augustine lawn can become constantly water logged, which in turn will make the turf soft and weak and easily damaged from normal wear and tear conditions, the lawn will be far more susceptible to moss, bare patches, diseases, weeds and pests, and will always be unsightly from the resulting recurring damage.
Water logging in Saint Augustine turf is a soil drainage issue, so repairing soil drainage will be the primary focus of this article to fix this problem and try to bring our Saint Augustine lawn back to full health.
Saint Augustine Lawn Coring
Our first approach to curing water logging is to core the lawn and soil. This is a process which is done by the use of a lawn coring machine, which can either be hired, or a contractor can be brought in to do the job for us. We advize the use of a contractor due to the weight and difficulty of the machine for new users to safely operate.
Lawn aerification is done by using this machine to punch steel tubes, called tines, into the turf and soil, which in turn removes plugs (cores) of turf, thatch and soil from the lawn. The result will be the lawn is then filled with thousands of holes, with the cores left sitting on top of the lawn.
These plugs will need to be removed, either by the use of a rotary mower to catch them and pick them up, or by raking them up and disposing of them.
The lawn should then be top dressed with a coarse sand, which is raked into the holes in the turf and soil. This coarse sand will allow for far greater water flow through the soil, as well as allowing more oxygen to the roots of the turf, both of which are vital to good lawn health, and in aiding in the reducing of water retention of the soil.
For soils which have major water logging problems, the lawn aerification process can be repeated once a year until the lawn and soil is fully draining and no longer retains excess water.
Wetting Agents are applied to a lawn in the same manner as fertilizers. They can come in the form of a granular agent which is spread by hand or a fertilizer spreader, or in liquid form which is sprayed onto the lawn.
Wetting agents can also be applied by turf professionals.
Wetting agents help soils to more freely circulate and flow water, and as such will allow a water logged lawn soil to more freely disperse of excess water in its profile.
Wetting agents will in no way be a cure to heavy water logged lawns, but should instead be considered as an aid in the repair of the problem in addition to lawn aeration, and as an aid to help water circulate more freely in the soil for as long as they remain active.
Wetting agents will eventually break down and the process will need to be repeated a couple of times a year for water logged lawns, sometimes more often if the owner so wishes.
For the worst affected Saint Augustine lawns and soils, wetting agents may often prove a futile exercise if used on their own and without proper soil repair being undertaken at the same time.
Not All Water Logged Soils Can Be Repaired
Real repair for water logged soils can only ever be achieved by changing the profile of the soil from one which retains water to one which disperses water more freely, and the best way to achieve this is with the use of lawn aeration, and addition of coarse sand.
While such lawn coring can greatly help with many water logged Saint Augustine lawns, the effects do have limitations, and will not repair all lawns or soils.
The reason for this is that the tines which create the holes in the turf and soil can only go so deep, perhaps only an inch or few at best, and for heavy clay based soils this just will not do the job adequately. Because once we get beyond those few inches - we're right back to the cause of the problem, which is the same clay or silt based soil which is still causing exactly the same problem.
So what's the solution for these real problem soil types?
First, the lawn owner must judge for themselves whether the combination of lawn coring, coarse sand replacement and wetting agents will work for their own lawn environment. As it would be impossible for us to even consider individual soil analysis for the reader's home lawn in this article. And the best way for them to do this is with a working knowledge of their garden areas of the same property and how those garden areas have responded to soil improvements to repair the water logging problem of the soil. If the soil adjustment was only minor, then coring etc should work equally as well for the Saint Augustine lawn.
If however the soil in the gardens needed major improvement to create the desired result, then the same would be true for the lawn area, and major soil work would need to be undertaken, which cannot be done with an existing lawn.