Weed Spraying Explained – Spraying The Blue Stuff

In the past few years, weed spraying to control unwanted weeds and grasses in lawns, planting beds, and other areas has become more and more popular and visible. I’m sure you’ve noticed the “blue stuff” a lot more on lawns and other areas during certain times of the year.

This article will help define the different types of weed control spraying applications, their different uses, different types of herbicides used, and how they may be beneficial to you.


First, a note about The Blue Stuff – A lot of folks are under the impression that the herbicides and weed killers themselves are blue and that the amount used is indicated by how dark or light the blue color is when applied.

Actually, the blue color is just an indicator dye that allows the applicator to see where they have already sprayed. This helps prevent excessive overlapping and over spraying which makes the applications safer and more economical.

While you’ll notice that some lawns and other applications are very dark blue, at Horizon we generally keep our applications on the light side. We do this for a few reasons. While the indicator dye is relatively inexpensive, the accumulated cost of many yards can add up. And of course that cost has to be filtered into the price. As well, a lot of our clients have expressed that they don’t care to have their properties blue for weeks.

So, we only use as little as needed for us to see and do and get effective results. Again, the depth of blue is not an indicator of the active chemical ratio.


Types Of Herbicide Weed Sprays

There are several different types of herbicides and weed killer sprays to address specific applications for different results. I won’t get too scientific with this. I’ll do my best to explain everything in a way that’s easy to understand. See Weed Control And Herbicides for a more detailed explanation of all the ins and outs of these types of chemicals and how to use them.

First, There are selective and non-selective herbicides.

  • - Selective Herbicides – These are chemicals that are used to control and kill some vegetation species without harming others. These are most commonly used in lawn applications or planting beds with desirable plants and trees. For example, dandelion or sand bur can be targeted and killed without harming the surrounding lawn turf. As well, there are some that will kill one type of grass without harming another grass type.
  • - Non-Selective Vegetation Killers – These are generally used in areas where no vegetation is desired or to spot spray in confined or other areas. A good example of a non-selective herbicide is glyphosate (Roundup). It is designed to kill most plants including grasses.

Pre Emergent

Again, not to get too scientific, pre emergents are designed to stop weed and other plant seeds from sprouting and growing. They generally don’t have any effect on existing vegetation that’s already growing.

There are many types of these chemicals in different strengths and chemical make ups to target different plant groups, species, and application areas. The most common areas where these are used are lawns and planting beds. Most are selective as explained above.

Post Emergent

Post, meaning after, emergent herbicide weed killers are designed to kill existing vegetation that is actively growing after it has already sprouted. These can be used in most applications but are also commonly used in lawns and planting beds. These can be selective or non-selective as explained above.

There are a lot of these chemicals that target different groups and species as well. A good example of a selective post emergent weed killer used in lawns is 2,4-D. This is one of the most common herbicides for lawn use that is still available to the general public in products like Ortho Weed-B-Gone. For example, it can be used to target dandelion without harming the surrounding lawn.

Bare Ground Soil Sterilant

These herbicides are always non-selective. They kill all vegetation including grasses for an extended amount of time. These are most generally used in industrial sites, oilfield weed control, fence lines, driveways, vacant lots, and planting areas without desirable ornamentals, trees, and other plants.

Bare ground soil sterilants can be very dangerous and unpredictable if not used correctly and cautiously. Honestly, they should only be applied by licensed knowledgeable pest control applicators.

There are a few reasons these chemicals can be so dangerous. One, if the wrong type for the wrong situation is used, it can be moved from the target site by wind or rain. If it is moved into an area where desirable plants are, the results are predictable. A lot of beautiful ageless trees have been lost due to this.

Another is when these chemicals are spray close to or over the root zone of desirable plants and trees. Again, these chemicals can move laterally and vertically in the soil due to wind and irrigation.

And yet another is when irresponsible applicators spray during breezy or windy conditions. Even the slightest breeze can cause enough drift to harm or kill nearby plants. Again, spraying these herbicides should only be done by licensed experienced applicators.


So there you have it. A little non scientific easy to understand explanation of weed spraying and what the blue stuff is.

I would also like to add that there are a lot of these post and pre emergents that come in granular form which are often more practical for the home owner who wants to do it themselves. Most folks don’t generally have access to the type of commercial sprayers that professional applicators have. If you do it yourself, Read and follow the label. It’s the law.

If you plan to do it yourself and have application or safety concerns, feel free to give us a call. Or if you would like professional weed spraying and control services for your lawn or property, give Horizon a call today at 575-725-9331.

 

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