Question 1

What is pre emergent?

Accepted Answer

“Pre emergent” simply means “before emerging.” This material stops seeds from germinating, which prevents weeds before they ever begin. Because pre-emergent products only affect seeds, they can usually be sprayed over existing plants without harming them. According to manufacturers’ labels, pre-emergent products last from 4 to 8 months when applied correctly. In Arizona, depending on the property and the weather, we can generally expect a solid 6 months of pre-emergent barrier protection. No matter the property, applying pre-emergent to landscaped areas every 6 months is the best approach to keeping your property weed-free.

Pre-emergent products work by inhibiting key enzymes in seeds or in the very early seedling growth of unwanted plants. This enzyme inhibition suppresses cell division and elongation, preventing the seedling from germinating and resulting in no weed growth. Many pre-emergent herbicides are classified by the HRAC (Herbicide Resistance Action Committee) based on their mode of action, such as microtubule assembly inhibition, which prevents plants from progressing beyond the seed or seedling stage.

Pre-emergent herbicides are registered for use across a wide range of applications, including both croplands and non-croplands, in accordance with regulatory agencies such as the EPA in the United States.

Question 2

What is post emergent?

Accepted Answer

Post emergent refers to products used once the weed has emerged from the ground, or "Post emergent".  There are two main types of post-emergent products: systemic and contact. These products can also be classified as non-selective (will harm any plant they come into contact with) or selective (designed to target specific weeds while leaving desired plants—typically turf—unharmed).
 
Systemic Post-Emergent:
Systemic post-emergent products are typically applied using ground broadcast equipment directly to the unwanted plant. After absorption, the herbicide moves throughout the plant, inhibiting a key enzyme or biological process necessary for its growth. This disruption causes the plant to die over time. Because systemic products work throughout the entire plant, they generally take longer—often 10 days or more—to fully eliminate the weed. However, they are effective at killing the entire plant, including the root system, not just the visible growth above ground.
 
Contact Post-Emergent:
Contact post-emergent products are also applied directly to the unwanted plant using ground broadcast equipment. These products work by destroying only the parts of the plant they come into contact with. Because they do not move throughout the plant, they act much faster than systemic products, typically producing results within 24–48 hours.
 
Selective Post-Emergent:
Selective post-emergent products are primarily used in turf areas to target unwanted broadleaf weeds and certain grasses without harming the desired turf. Their mode of action may be either systemic or contact, depending on the specific product, but they are formulated to selectively affect only certain types of plants.

Question 3

Will your service stain my landscape?

Accepted Answer

Color temporarily, yes; stain, no!  The color is called a spray indicator and allows our applicators and clients to visibly see what has been sprayed and what hasn’t.  With some products, the color is built into the material at the factory and we don’t get a choice in the matter.  With others, we elect to add a colorant to our mix for our applicators to do their job correctly.  Most added colorants will dissipate through UV exposure or rain.  With colorants, the typical time for color to last is about 2-3 days.  Color may last longer in shaded areas.

Question 4

When should I spray pre emergent?

Accepted Answer

If you haven’t had one done in the last six months, the answer is now! It is a myth that there is a best time of the year to apply pre emergent.  We are a year round business and can attest that weeds grow every month and rain falls every month. Just because you may not have weeds doesn’t mean you don’t have seeds just waiting for the next drop of moisture to germinate.

Question 5

So if I do a pre-emergent application I’ll never see another weed...right?

Accepted Answer

Weed control is an imperfect science.  Pre-emergents create a barrier on top of the soil to prevent new seeds from germinating, however, any disturbance in that barrier will create an area that is not protected.  We can treat two identical properties side by side and one will be pristine, while the other has areas that need further attention. This is why we stand by our service and give you a 6 month warranty on pre emergent treatments.  Any time there is a break through of weeds, just call us and we will come back and treat those areas at no additional charge.

Question 6

Will you spray pre-emergents on the sand under the swing set, in the sand box or the dirt in the horse corral?

Accepted Answer

No, no, and only at the animal owners request.  In order to be as safe and environmentally conscious as we can, there are certain areas that we will stay away from.  While pre- and post-emergent products are safe for humans and pets once they are dry, there are still areas that we will stay away from.

Question 7

I am laying new landscape rock. Do I use pre-emergents before or after I lay the rock?

Accepted Answer

The rock will often come with unwanted weed seeds in it, therefore we advise putting the pre-emergent down after the rock is spread. If there were weeds or grass in the area where the rock is going then you should have a post-emergent application before the rock is put down.  On commercial properties we will often apply pre emergent products before the rock is laid, and after the rock is installed, but we never advise only applying pre emergent before the rock is installed.

Question 8

Will pre and/or post emergent applications harm my pets?

Accepted Answer

Herbicide manufacturers clearly state that the application is safe to humans and pets once it is dry. We recommend that pets be kept off the treated area until it is dry, aerated, or dissipated.
 
We are continually amazed that most people ask about the pets but rarely about their children!  We reccommend that young children are also kept off of the treated areas until it is dry, aerated, or dissipated.

Question 9

Do the pre-emergents or post-emergents you use sterilize my ground?

Accepted Answer

No. It takes a different, stronger, material to do this and we won’t use these stronger products on residential or Home Owner Association properties.  Even on commercial properties, much care must be taken when applying a sterilizing product.

Question 10

It rained shortly after the pre-emergent application. Is it still good?

Accepted Answer

Yes. In fact it’s not only good, it’s great!  The efficacy of pre emergent porducts are increased when they are followed by some rain within the labelled timeframe.  for the most commonly used pre emergent, Specticle Flo, that timeframe is 5 months.

Question 11

What if it doesn't rain after my pre emergent application?

Accepted Answer

Pre emergent likes having rain after application, however, it doesn't need it to work.  Studies have shown that rain or not, pre emergent herbicides are generall within a few percentage points of efficacy whether or not their is rain follow application.  In either situation, we warranty our work for the life of the pre emergent, so you are covered!

Frequently asked questions