Dear zaclohrenz,

Thank you very much for your inquiry. I love this question as it gets to the very heart of lawn care issues. Every part of your question is correct and leads to my answers. The first thing we need to realize is that weeds are opportunists and are growing where we allow them to grow. Weeds are not the cause of poor turf, but rather the effect of poor turf management. The three way weed killer sold at most stores like Wal-Mart, Lowes etc. contains the herbicides necessary (2,4 D, MCPP, and dicamba) to control the vast majority of weeds in our lawn assuming you are applying them at a time that is best to control the weed in question. For dandelions, the best time is actually in early fall and the second best time is just after they have flowered in the spring.

The big question is how the other cultural practices are contributing to your weed population, namely mowing, fertility and watering. If these are out of balance, putting down the weed killer can get pretty tiresome as the results will not be dramatic.

To begin with, you must mow frequently and follow the one-third rule. This means never cut more than one-third of the leaf blade off in any single mowing. This promotes turf density and the density is the key to preventing the light requirement for the weed to germinate. Second, follow a balanced nitrogen fertility plan. Apply judicious amounts of nitrogen when the grass is actively growing. For cool season grasses, this centers on spring and fall and for warm season grasses, late spring and summer. Do not over fertilize as this will cause rapid growth and then you will end up scalping the grass if you cannot keep up with the mowing and then weeds can encroach.
The final issue is watering. This one is not straight forward as climate, soil type, grass, and time of year will dictate the water needs of the plant. One rule to begin with is to assume that your turf will need 1.0 inch of water per week during the growing season. This can be applied in a variety of ways and rainfall needs to be counted in the total. For best results, try to water early in the morning. The wind is at it least and you can be the most efficient with the least contribution to disease pressure.

I hope this helps and gets you started towards your goal. Again, thanks for the question and let me know if you have more.

Respectfully

Trey Rogers
The Yard Doctor

Thank you for your reply!

I suspected that keeping the grass short, instead of allowing to grow tall, was a big part. I thought the weeds were stunted a bit if you did this.

As far as watering, is there a set number of times you should water between mowings, or does this matter? I normally try to water everything once between mowings.

Is there any treatment I can do during the summer itself to get rid of weeds? The weeds are starting to take over again, and chemicals from WalMart seem not to help much.

zaclohrenz,

Everything the Yard Doc said is what is always set forth as dogma in lawn care books. In addition to what he advised, you might want to bite the bullet and, even if you don't know your neighbors, ask them what precisely they do to keep their lawns weed free and in such great condition. (Especially since they live in your micro climate and deal with most issues that crop up in your neighborhood, lawn-wise.)

They already have a jump on you as it usually takes some experience plus a headstart and a couple of years when working with a new or existing, well-maintained lawn to keep it that way.

Most people take pride in well kept lawns and are proud of their lawns and should be happy to impart their wisdom. Only a few are not so socially amenable. I would recommend asking; certainly couldn't hurt!

Dianne