FERTILIZING YOUR LAWN
At the end of a long Winter, most of us are “Green” deprived. Forget the robins, the first true sign of Spring is a green lawn, especially if it is yours and not your neighbors! This causes the first gardener’s phenomenon known as the Spring suburban fertilizing frenzy. As soon as the first Garden Center gets its delivery of fertilizer, an almost immediate line of cars pull in right behind it. They take it home and dump it on their lawns to be the first ones with a deep, dark green lawn. It works. The grass blades shoot up and they are such a dark green its almost blue. But the problem is weeds thrive right along side of the grass. Diseases strike the overworked grass plants. Lawnmowers barely have enough time to cool off before the grass needs cutting again. The worst part is after the lawn comes back to its normal color, the homeowner rushes back to the Garden Center and buys more fertilizer to start the cycle all over again. The sad part this constant fertilizing instruction was coming from “Turf Experts”. Today the word is enough is enough!
Researchers have now found out that all that fertilizer is actually harming the lawn instead of helping the lawn. Studies at the Alabama Polytechnic University shows that 1/2 of all the soluble nitrogen leaches out of the soil before it can be absorbed by the grass plants. And even the remaining half may be doing more harm than good. Grass plants are very efficient in their use of nitrogen, and can even be considered “fuel efficient”. Babying the lawn by putting all the fertilizer on it may actually reduce the natural efficiency. The is a ton of microorganisms in the soil that are harmed when excessive fertilizer is used, and this can upset the efficiency of the grass plants. Basically you are growing your lawn to death. The best lawn I have ever seen was on Crescent Avenue in Ramsey. The homeowner used 5-10-5 twice a year and the lawn was a beautiful green color for most of it.
When you fertilize, all the nutrients remain at the surface area of the soil. The natural tendency for grass is to have a deep and quite expansive root system. The roots do not have to travel to find nutrients when it is at the soil surface, and compaction can occur, and more importantly, in the summer the lawn will die without excessive watering. Another problem is fertilizer (non-organic) can actually acidify the soil and kill beneficial biological processes. A seven year study at the University of Kentucky showed that increasing fertilizer amounts drastically decreased the pH. The amazing thing learned was that the lawn that had the least amount of fertilizer had the lowest levels of thatch. At the highest levels, there were 65% less earthworms than at the lower level, which was due to the lower amounts of calcium, which is important to the earthworms metabolism.
We should instead address the soil instead of the topgrowth. A lawn can only be as good as the soil it is growing in.
Organic fertilizers take time to break down and add nutrients to the soil. As the break down, they feed the roots and allow them to produce carbohydrates, which is the energy source in plants as well as people. The goal of fertilizing is to build up this reserve of carbohydrates for times of stress, and to keep the plants growing steadily and healthily during these times.
Lets think about the normal fertilizer application schedule for one minute. In Spring, they suggest a high nitrogen fertilizer to get the lawn growing. This high nitrogen application causes the grass to have spurt growth, and it draws upon its carbohydrate reserves. The grass gets “hooked”, just like a drug addict, dependent on more fertilizer. The excessive growth also draws again on its carbohydrate reserves to help heal its wounds from the grass cutting. The roots don’t develop as they should, so when the hot weather comes, they are unable to dig deep for moisture. During the second application towards Summer, another high nitrogen application is suggested to continue your lawn to look its best. This application increases the respiration of the plants which again reduces the carbohydrate reserves. The grass weakens. At the end of Summer, you have to reseed and use a fall fertilizer to get the grass growing. And before you know it, it is Winter and the lawn goes into this dormant period without adequate reserves of carbohydrates to get it to Spring. And then the cycle begins again.
Tomorrow we will discuss the individual nutrients and the plants' needs. For more information you can read my Organic Lawn Care Manual at http://www.thegardeningguru.com/index-11.html.