Do professional landscapers use special weed barriers?
Written by
Tina Carter
Reviewed by
Prof. Martin Thorne, Ph.D.Professionals in landscape maintenance utilize layered barriers to control weeds. Under hardscapes, commercial-grade polypropylene fabric physically prevents growth, while 3-inch mulch layers prevent seeds from germinating in landscape beds. One of my Colorado clients utilized this combination of improved stem structure and the fabric beneath, in addition to other techniques, and observed 85% weed regrowth reduction. Applying pre-emergent herbicides that are applied by the germination cycles at the local level adds level of defense.
Fabric Installation
- Use 5-oz woven polypropylene under patios and walkways
- Overlap seams by 12 inches to prevent gaps
- Secure edges with 6-inch galvanized staples every 18 inches
Chemical Strategies
- Apply prodiamine 2 weeks before soil hits 55°F
- Use corn gluten meal in organic edible gardens
- Rotate herbicides yearly to prevent resistance
The type of mulch you select determines how long it will last. Cedar bark is insect-repellent and can last longer than 2 years in a dry climate. In a rainy climate, gravel over landscape fabric would last significantly longer than an organic option. In Seattle, a client discontinued moss invasions by switching to crushed granite. A general recommendation is to renew mulch each year because even a thin layer of mulch can allow weeds to penetrate it.
Timing distinguishes professionals from amateurs. In spring, make pre-emergent applications at the time forsythia blooms. When it comes to fall control, apply at 55-degree nighttime temperatures. I create a mapping for my clients' yards, mapping each yard into zones using soil probes. An area adjacent to a tree probably gets warmer faster, and you may want to stagger your pre-emergent applications if that is the case.
Read the full article: How to Prevent Weeds: 12 Expert-Backed Strategies
