While you are out in your landscape doing your spring clean up you may be seeing a lot of winter annual weeds start popping up in your landscape. These weeds include henbit, dandelions, and clover (clover is a actually a perennial). Winter annuals actually germinate in the fall and go dormant until early spring when the soil temperatures start to warm up. To save your Saturday mornings for something more important than pulling weeds, you should treat your landscape in two stages.
First, kill the existing weeds. I recommend using Fertilome Kilzall or Fertilome Weed Free Zone, the product you choose will depend on where you are using the product. Both products will control just about every weed we have in early Spring. Mix up the chemicals according to the directions on the bottle and avoid applying them on a windy day.
Once the weeds are dead you should apply a pre-emergent weed control to help prevent new weeds from germinating. A pre-emergent is a compound that bonds itself to the top layer of soil. Once a weed begins to germinate the product does not allow the weed to fully develop and it dies. There are three different classes of weeds you need to know about when selecting a pre-emergent: annual broadleaf weeds, annual grassy weeds like crab grass, and perennial grasses. There are no pre-emergents available on the market labeled to control perennial grasses like fescue or Bermuda grass. Chemicals available to control these plants are too toxic for shrubs and trees. My best advice is keep a small bottle of Round Up or Killzall available to spot spray those plants.
For broadleaf and grassy annuals there are two different products available that you can choose from. Treflan is the active ingredient in the well known product Preen. We carry a Treflan based product called Weed and Grass stopper. It is a much more affordable product than Preen and is labeled for use around annuals and a wide variety of garden crops. Because it is safe to use around ornamentals and vegetables, Treflan has a shorter life span compared to other products, so it needs to be applied every 4-6 weeks depending on weather conditions. I have spoke with many customers disappointed in the performance of Preen or other similar products who did not know it needed to be reapplied. Be diligent in your application of Treflan and you will see significant reductions in the amount of weeds in your landscape.
The second pre-emergent for annual weeds is Snapshot herbicide. This product was only available in the commercial market for many years but has recently been approved for homeowner use in some ornamental settings. Snapshot is a combination product that uses Treflan and another product called Gallery. When these two products combine you gain a much wider spectrum of broadleaf pre-emergence control and a longer residual period than Treflan alone. We use Snapshot extensively in our landscape maintenance services and have been very happy with the results. It is a bit more pricy than Treflan but the results are well worth it. The downside to Snapshot is that it is not approved for use around annual plants such as flowers or vegetables. If you are using this product close to an annual bed be sure to give yourself about a 12 inch buffer area.
No matter which product you use to control weeds, always read the labels carefully and wear the recommended safety gear.