The most effective lawn weed control strategy is to take measures to prevent it in the first place. If you establish your lawn properly and do proper regular lawn care and lawn maintenance, chances of your encountering a weed problem will be very slim indeed. Weed control on your lawn can really be as simple as that.
Weeds usually grow best in open areas where there is minimal competition from turf grass. With proper planning and proper lawn establishment you can help your lawn defeat weeds in the competition for light, nutrients and water. In this kind of scenario, when and if a few weeds appear it is then easy to hand-dig them out rather than use herbicides. Not only is it much cheaper but it also saves time and is healthier and better for the environment.
Proper lawn establishment means that the landscape chosen matches your needs with the environmental conditions and soil type available. It is also important that before you seed an area you ensure that the area does not contain any quack grass. This is a very aggressive weed that can easily take over your entire lawn.
If there are signs of quack grass and other perennial weeds then they should be removed with a sharp spade and the area should then be filled with weed-free soil or sod. Alternatively you can treat the weed areas with herbicide glyphosate and then till the soil and re-seed after seven days.
The other thing to remember is that south-facing slopes are usually hot and dry during summer, just the sort of conditions that will cause weeds to grow a lot better than turf grass. You may want to consider other landscaping options for these situations, for example prairie grass or wild flowers.
The soil can also encourage weeds in your lawn and make lawn care and lawn maintenance very difficult. Poor drainage and hard soils can cause serious turf problems. Weeds such as the annual bluegrass will usually thrive in this environment. The solution here is to try your best to improve drainage by tilling the soil and spreading it out. Eliminating low spots where water tends to collect and re-grading will also improve drainage and help correct this situation.
Selection of the seed you intend to use on your lawn will also have an impact on weed control later. Here it is advisable to use grass seed that contains very little weed seed. Is also wise to use varieties that are resistant to diseases that may be common in your particular area. Also check the amount of light your grass will ordinarily receive. If your back yard has a lot of trees then select a shade-tolerant grass species such as fine fescue.
Proper lawn care and lawn maintenance usually play a major role in weed control. Weeds ordinarily thrive in bare, sunny soil but are easily foiled and suffer under tall, dense turf. So when mowing your lawn, set your mower to 2 inches to provide more leaf area to shade the soil. You can then make sure you mow your lawn more frequently.
Having said all this, it is also true that even lawns that enjoy the best lawn care and excellent lawn maintenance will sometimes still be invaded by weeds. To have a truly weed-free lawn, you may have no alternative but to resort to the careful and selective use of weed control herbicides.
But first it is important to identify the weed or weeds which you are trying to control on your lawn. The reason is simple. Not all lawn weeds are controlled via the use of one specific herbicide. Quite often, the lawn owner will need to use two or more herbicides to obtain the desired results.
It is also imperative to bear in mind that the use of herbicides for broadleaf weed control will only kill weeds present at the time of application and will not prevent weed seeds from germinating and developing on the lawn at a later time.
Great care should also be taken when applying herbicides near trees, shrubs, flowerbeds, and vegetable gardens. It is possible for herbicides applied to these other plants to cause damage or even death to the plants.