Have you ever determined that you're going to clean the basement, garage or barn and just become frozen in place because you can't determine where you should start on the massive job? Did you ever just say to yourself "forget it!" and go do something else instead? Well, the same thing happens when you decide to face down that weedy mess that you hesitate to call a Lawn. You know that it will take several different weedkillers, but you don't know which ones and in what order, or when they should be repeated to finish the job well.
*** Northern (Cool-Season) Version***
It's very possible to turn around a yard that is very weedy, but it takes time and patience. If you're looking at tons of different weeds and not just a few, the Triangle Approach is for you. Let's set some background...
There Is No Magic
Despite what many suppliers of weed killers will tell you, there is no single weed killer that will kill all types of weeds without harming your lawn. There are weed killers for diiferent broadleaf weeds, and others for grassy weeds. Just because an herbicide is more expensive does not indicate that it kills more weeds - it may be expensive because it focuses well on one weed type or species very well.
And while they may be easy, "weed and feed" products don't work as well as herbicide-only products - I'll discuss why later in this article.
When to Tackle Weeds
The best time to tackle a plethora of weeds is when most of them are actively growing. In the North, this is generally late April until Memorial Day, and then early Fall. Summer is not the best time to tackle them - grasses and most weeds are in a slower "survival mode" waiting for the best growing conditions of Fall.
The Triangle Approach
Picture a triangle with the fat part on the bottom. We don't want to bother figuring out what weeds you have if your lawn is infested with 20 different weeds. We want to eliminate most of them with an inexpensive, readily-available, easy-to-apply weed killer. First, we apply a fertilizer to get them growing, This causes a growth spurt, and the metabolism goes up. Somewhere between Days 10-14 this tendency peaks (it is longer for organic fertilizers). "Weed-and-Feed" products can't take advantage of this growth spurt, because they apply the fertilizer and the herbicide at the same time. This is the moment to strike - hit the weeds with a general-purpose broadleaf liquid weed killer containing 2,4D - possibly in combination with Dicamba and/or MCPP. This is a broad-spectrum kill that will get lots of easy-to-kill weeds. Generally it is a fairly fast kill of 7-14 days. Brand names do not matter - the ingredients do. If you had a lot of weeds, you may repeat the treatment a second time. In general, sprayed liquid applications work best, as they are absorbed by both the leaves and roots.
The middle part of the triangle is for the tougher weeds that don't knuckle under to broad-spectrum killers. If you started with 20 weed types, you'll probably be down to 3-4 types now. These will generally be things like Clover, Chickweed, Oxalis, Wild Violets and Ground Ivy. It's a good idea to get these weeds identified by someone on AROUNDTHEYARD.COM. The weed-killers needed will not be household names, but will be widely-available. The kills will be slower - often 2-3 treatments 14 days apart, with nothing visibly damaged for a long time. Stay the course - the weed killers work. The weeds may just get smaller and weaker without yellowing. The most common herbicide at the Level 2 part of the triangle is Triclopyr, when found in concentrations of 8% or so. Lower concentrations often fail to complete the job.
The top of the triangle is the use of specialty herbicides. Often by this point you're down to just grassy weeds, but these are the hardest to beat. The weed killers will be names you often have never heard of, and they can be more expensive to buy, difficult to find, and exteremely touchy about being applied correctly. This phase may be one that some novice lawn owners skip - they choose just to live with grassy weeds as part of the permanent situation. If you proceed to this level, you will definitely want to get detailed assistance from an experienced member on AROUNDTHEYARD.
Following the Triangle Approach keeps costs down and eliminates a lot of frustration. You see progress and results. It takes patience, but works 90%+ of the time.
The Triangle Approach works best when it is followed as described, and in order. Skipping steps/levels, increasing the specified application rate, creating "cocktails" that mix chemicals from different levels, or doing the steps in a different order are not recommended, and may cause harm to the lawn, soil or nearby plants.
That's it! Please feel free to post questions you may have related to this article on AROUNDTHEYARD...