Rock Areas admin March 24, 2023


Stop Rock and Mulch Bed Weeds All Season Long

Stop weeds before they start! The best way to reduce the need for weeding by hand or use of products like Roundup is by preventing weeds from growing in the first place! Organo-Lawn uses a very special pre-emergent weed control called Specticle to prevent weeds from growing in rock and mulch beds.

Specticle is a pre-emergent weed control that is applied to rock areas, mulch beds and sometimes driveway cracks. This preventative weed control stops weeds from growing for up to 10 months. The product is extremely environmentally friendly and won’t leach from the soil into the water supply. In fact the product won’t even move an inch in soils.

It is important to schedule this service early in the season because this pre-emergent weed control must be applied prior to any weed seeds germinating. These weed control applications occur during the winter months. We perform pre-emergent rock and mulch bed applications during the months of November through early March. These applications cannot be applied on top of snow, therefore we recommend scheduling these applications as early as possible.


Preventative Weed Control for Rock and Mulch Beds

Landscape Bed Weed Control

This special weed control truly saves countless hours of hand weeding and it virtually eliminates the need to spray weeds with products like Roundup. If the weed control is applied prior to the weeds germinating, the weeds won’t be able to grow for up to 10 months.

This product does not disturb perennial plants, bulbs, or any established plants such as as shrubs, trees, or existing flowers.

The application occurs during the winter months when most people are not thinking about weed control. The reason for this is because the product creates a barrier in the soil and the weed control will only stop weeds from growing that have not germinated already. Many weeds begin to germinate very early in the season. During warm winters, some weeds start growing as early as February. Once a week has germinated, it cannot be controlled by this product, even if you cannot see it yet!

We strongly recommend having this application applied in November. The reasoning behind a November application is that it is easier to work around snow storms at this time of year. If it snows in February, the weed control application to the rock and mulch beds will not occur until after the snow melts. If the snow is deep enough and the weather is cold enough this could prolong the application until March.

Plant in Healthy Soil - Boulder

How Effective is Specticle?

Does it Stop Weeds?

Yes, we have been using this pre-emergent rock and mulch area weed control for many years and it works great! The first year the product is applied we expect to see around a 90% control rate on weeds. The 10% of weeds that come up are usually weeds that have already germinated. If the application was applied in November we expect to achieve a 95% or higher weed control rate.

How the Product Works

  • Specticle has the active ingredient Indaziflam. This ingredient attaches itself to soil and will not move. This product bonds itself to soil so tightly that it won’t even move one inch. Therefore, this product won’t leach into water.
  • The weed control will prevent weeds from germinating for up to 10 months.
  • The weed control works better in Rock areas than it works in mulch beds. Expect to see weed control rates around 90% or more in rock beds and 60-80% in mulch beds.
  • Organo-Lawn performs these applications from November – early March. Specticle needs to be applied prior to weeds germinating and the best results are achieved if the product is applied well before soils begin to warm up and weeds begin to grow.
  • After the application is completed it is recommended to water the product into the soil. If there is no rain or snow within 1 month of the application the product does need to be watered into the soil for it to work properly.
Rock Area Weeds

Preventative weed control works better if it is applied as early as possible. Winter (November – February) is the ideal time to have the product applied.

Pre-Emergent Weed Control Application Season

Ideal Time for Rock & Mulch Bed Treatment

December through February is the best time to have this rock and mulch treatment applied. We apply this product during warm days when there isn’t any snow on the ground. The product lasts 10 months and is broken down by microbes in the soil. There is almost no microbial activity in the soil during the winter months and a winter application will last just as long as an application that is done in March.

Treatment Season:

November – early March. If there is snow on the ground we cannot perform the application and we recommend scheduling this service as soon as possible.

Specticle Information

Specticle Flo is registered with the EPA by Bayer, EPA reg. #432-1518. This rock and mulch weed control is also registered with the Colorado Department of Agriculture.

Specticle Flo is a synthetic pesticide containing Indaziflam. If you are chemically sensitive or if this is a major concern for you we will be glad to work with you to develop an appropriate organic lawn care alternative for you and your weed control needs. * Click on the PDF link above to download a Indaziflam toxicology PDF file.

Schedule a Pre-Emergent Weed Control Application for Rock and Mulch Beds

If you have any questions about Specticle weed control for rock and mulch beds, please give our offices a call to discuss your weed control options. Boulder (303) 499-2000 or Fort Collins (970) 225-9425

FAQ – Weed Control for Rock and Mulch Areas

Is Specticle Weed Control Safe for Kids and Pets?

According to the Colorado Department of Agriculture it is illegal to claim that any weed killer is safe. Therefore, even though Specticle Flo is on the EPA’s reduced risk list for pesticides, we legally cannot say it is a safe for kids or pets. According to the Department of Agriculture, water is not safe. We have spent many hours researching this product and have found that all the research indicates that this product is extremely low toxic to people, pets and the environment.