When to Spray Ortho GroundClear

By Kyle Lanning

Ortho GroundClear Complete Vegetation killer is a leading herbicide that boasts a year of complete vegetation control after application. It works by killing existing weeds and grass down to the roots and preventing weed seeds from sprouting for up to a year. It can be used during preparation for new patios or sidewalks, or when clearing away any other area where vegetation is undesirable. For best results, Ortho GroundClear should be sprayed under specific conditions.

House exterior
credit: Jupiterimages/Comstock/Getty Images


According to the product information included with Ortho GroundClear Complete Vegetation Killer, you should use the product when the daytime temperatures are at least 60 degrees Fahrenheit (approximately 15.55 degrees Celsius). This means that you should plan ahead before spraying. Check the temperature range on the day you are considering using the product and make sure that it will be above 60 degrees Fahrenheit for the majority of the time the sun is present. In addition, consider starting as early as possible because the earlier you spray Ortho GroundClear, the more time the product will have to work in the optimal temperature range.


Ortho GroundClear works best when the soil is slightly moist. Directions for use listed on the Scotts-Miracle Gro website state that if the soil is dry, you should moisten it before applying the product to see the best results. If you are doing a large area, or if you are unable to moisten your target area efficiently before application, you should wait to apply until after a light rainfall. Remember that this product works in part by killing the root systems of existing vegetation. This means that you should avoid applying the product if there is a chance of rain in the forecast. The product only needs a couple of hours to absorb and begin affecting the vegetation, but if it rains directly after application, you will not get the full effect.

Wind Speed

When you are selecting your application day, you will also want to take into account wind speed. Wind speed is a less important consideration then temperature or moisture levels, but it is still a variable to keep in mind when choosing your perfect application day. The reason that you want to avoid applying Ortho GroundClear on a windy day is the increased potential for particle drift. High wind velocity can cause particles of the herbicide to alter course and land on unintended areas. Wind speed becomes an especially important consideration if you are thinking about applying Ortho GroundClear near a sensitive area, such as around a border to a garden.