Oh That Lawn Again

Lawn in StrathamThe days of treating lawns as a chemical test plot are waning and that is as it should be. True it is fairly easy to make a lawn almost insect, weed and disease free by adhering to a strict chemical regiment, but do we really want to do this anymore?

An alternate option is the integrated pest management approach to having a nice looking lawn. This method balances correcting the growing conditions, seed source, predators and many other factors to achieve that desired lawn. In integrated pest management the use of chemicals is part of the program but their use is greatly diminished. Using this approach you can achieve a lawn that is every bit as nice looking as the old chemical plant that was once called a lawn.

The third approach is to go strictly organic. Here you may asking, can I have a insect, weed and disease free lawn using this method? And the answer to that is no. But you can have a lawn that meets your needs.

The question is do I want a lawn that looks like a golf green, the one designed by Schwartz Brothers Landscape Solutions St. Louis, or does a lawn with a few weeds disease or insects really meet my needs? My own lawn looks like a weed farm with some grass growing in it, but I pay no attention to it other then mowing, and I live in the country where my neighbors are distant and don’t care. Also I am comfortable in my status so I don’t need a lawn as a monument. That’s right, that is actually what a lawn started out to be, a status symbol.
When the English moved out to colonize and landed in hot dry areas, lawns were used as a bragging piece. As it was hard and expensive to maintain a lawn in these areas a large perfect lawn told everyone you were rich and powerful.

The wealth of knowledge concerning lawns is staggering as any Internet search will show.
I intend here to give you the basics of a good lawn maintenance.

Watering. This is the single most important thing that people get wrong.
Shallow frequent watering promotes disease, insects and poor shallow roots.
Most lawns, even in the grips of a drought, need water only once a week. Once every five days at the most. Water deeply and get between 1 to 2 inches on your lawn once a week, all at once if possible. (amount depends on grass type and soil).

If you have soil or slope problems and get puddling or run off before achieving this rate you may have to break the time up. Here is where you may want to go to the five day schedule and alter the amount to achieve the correct amount per week. It is easy measure how much water the lawn is getting by putting cans or other straight sided vessels out in various locations, running the irrigation for 15 minuets then measuring and averaging the amount of water collected. Remember rain counts in the weeks water total. Most good irrigation companies have systems that adjust for rain, but I can’t tell you how many times I see irrigation systems watering while its raining.

There are two exceptions to this rule, and that is if your lawn develops either a disease called Fusarium Leaf Blight or Necrotic Ring spot. A light daily watering can be used to reduce the severity of these diseases. This watering technique may then cause other problems so get more advice before using this practice to control these diseases.

Soil. Lawns like a rich well drained moderately high organic loam. If your lawn is rock, sand, gravel and or clay. You can have the whole thing torn up and replaced, or you can amend the soil a bit each year. Use organic fertilizer. Top dress with compost 1/4″ spring and fall. Aerate as many times as you can stand, and afford until you have changed the soil compaction. Once you have accomplished a better growing soil, aeration will only need to be done as needed. This is usually every couple of years depending on use and soil type.

Use a mulching mower. Return your clippings to the lawn using a mulching mower. This will increase the organic mater faster then almost any other means and reduce your need for fertilizing. Clippings will also return up to 1/3 of the lawns nitrogen needs back to the roots.I also prefer to run my mulching mower over my leaves rather then rake them. This also feeds and conditions the lawn. You will have to adjust your lime needs if you do this but I find it much easier to adjust my lime than rake leaves. A lot of lawn experts will tell you not to do this but I always did when I had a nice lawn and it works. Other then the PH adjustments no one can tell me why they say it is not good to do, so you decide. I recently found this paper that states mulching leaves of some species can reduce dandelion populations.

Seed source. Annually over seed with different seed types that are compatible with your lawn composition and likes. Different seed varieties offer different resistance to insects disease and environmental conditions. Seed producers are constantly developing new varieties of grass. A good place to get these new varieties is a real garden center such as Agway that has seed in bins that you can mix. The problem with newer houses is that the lawns are usually from sod farms and not seeded. Sod farms grow the best grass for their needs, usually a few varieties that grow fast, look good and do well in on their farms. They also intensely manage this crop. This is not to say that establishing a lawn with sod is wrong; it has its benefits, but it is even more important to introduce other varieties of grass to sod established lawns.

Fertilize and correct the PH. Grass will grow anywhere and so will weeds. But by adjusting your fertilization and PH to the optimum for grass you will help the grass out compete the weeds. Randomly fertilizing is pretty useless, wasteful and can increase diseases. My advise is to use your Agricultural Extension Service. Bring in a sample of soil and have it analyzed and they will give you the correct fertilization and pH adjustments. This is much too cheap for the service given, and absolutely invaluable if you want a nice lawn. Note that PH is as important if not more important then fertilizer. Plants can not effectively use fertilizer if the PH is wrong. Use organic fertilizer. I am not a one hundred percent organic practitioner, I do use chemicals where needed, but in this case I am fully on board with this practice. The reason for this is that organic fertilizers not only supply needed organic material but also Scientific studies show that they reduce disease. Basically the process of decomposition competes for the same nutrients that some diseases need. (Way to deep for this overview. Here is some research)

Weed control. You will not eliminate all weeds in your lawn even with a full chemical regiment. But once you establish a healthy lawn you might find that you can be comfortable with the amount of weeds that remain with just spot treatment or popping them out with a tool. If you have a stubborn weed problem it is usually not productive to randomly treat it. Here again use your Agricultural Extension Service. They will be able to identify the weed and steer you to the right solution whether you want to use weed killer or another method. Vinegar will kill weeds. It will also kill grass. It will not kill the roots of perennials so treating every time they re-appear is necessary. Pulling will kill weeds but any part of the root of some weeds will re-grow like Hydra heads. A propane blow torch also kills weeds, I am sure you can figure the negatives of this one by yourselves. It does work though. Corn gluten can in some circumstances act as a pre-emergence. It does this by applying a very thin high nitrogen layer at the soil surface which burns the sprouting weed. It is not very effective, is very short lasting and is really dependent on weather and other factors. Most independent research is not favorable to this product as a weed control option. It does at least supply nitrogen to your lawn so try it if you like. It is expensive and you will have to adjust your nitrogen applications respectively.
The best weed control is a healthy lawn. Grass has the second widest natural range of any plant, and it did not get this way by not competing with weeds. Guess what plant has the widest range and win a prize.*

Mowing. The best overall height for healthy lawns is 2 1/2 to 3 inches. Mowing frequently is better for the lawn then letting it grow long then cutting it way back. Keep lawn mower blades sharp. Dull blades leave ragged cuts that contribute to water loss and disease. If you have a service that cuts your lawn be sure that they clean their equipment before they cut your lawn. One of the fastest ways diseases move from one lawn to the next is by hitching a ride on a lawn mower.

Thatch. A little thatch is healthy, up to about 3/4 of an inch. Heavy thatch harbors pests and stops water reaching the roots. Most lawns if cut and fertilized correctly will not have a thatch build up. Over fertilization is the leading cause of thatch build up.

Disease. This is too short a piece to get the full scope on diseases. Just remember that weather, your watering, fertilization and seed selection will have a marked effect on the presence and destructiveness of diseases. Disease prevention should usually be left to these factors. If you do have a problem that occurs each year a preventative treatment might be warranted. Before you treat for any disease: First it must be correctly identified. Second it has to be determined that correcting the growing environment is not the right cure. Third, is this disease an infrequent occurrence that happens due to just the right weather conditions? Forth, can you introduce a resistant grass variety for this disease? And lastly if you wish to use a chemical control, is there an effective chemical control and is the timing right for application. If you use a service and they treat for diseases ask them what diseases they are targeting, what treatments they are using and are there any cultural treatments that will reduce the frequency and severity of this disease. If they don’t know or are miffed at your question hire someone else.

Grubs and other insects. Before you treat for grubs or other insects make sure you have a problem. Too many lawns are treated for problems that don’t exist. By treating for problems that don’t exist not only are we needlessly polluting the environment, but killing predators and chancing that the actual target insect will build resistance to the insecticide. Also it is a waste of money. Your Agricultural Extension Service will have information on how many of a particular insect per square foot must to be present to show any visible effect on your lawn. For example Japanese beetle need to be around 8-10 grubs per square foot to have any noticeable effect on a well maintained lawn. So there is no point in treating if the number is less then this. If you hire a service and they suggest treating for grubs, it is not an unreasonable question to ask how many grubs per square foot do I have and what insect are they. Sound really smart and ask if they are at the visible damage threshold. If they don’t know or are miffed at your questioning hire someone else.

Most grub problems until now have been treated with chemicals such as Dylox or Imidicloprid (merit). Both work. Both have to be applied right and at the right time. Both are toxic and can move to none target areas. There is a new chemical on the market that has just been incorporated into a granule. It is far less toxic to none target organisms and it works for all lawn pests. It is expensive and not widely available yet. My local Agway in Hampton knows about it. I may be lucky that it is run by a knowledgeable person who keeps up with new products, his name is Keith. The name of the chemical is Acelepryn.

Remember always follow the label and treat only if you actually have a problem.

The University of Connecticut provides a great resource page with a lot more information than covered here.

*(Just kidding no prize it is the Willow tree)

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