Defeat the weeds before they emerge in 2020

May 18, 2020 | By: Scott Robinson

Controlling weeds in maintained turf and ornamental beds here in Ohio is a constant battle for anyone who manages these areas. The most common methods used to control them are pre-emergent herbicides, post-emergent herbicides and cultivation/manual removal. Pre-emergent herbicides applied with the correct product for the target weeds, application timing and rate following label procedures can be very effective at reducing the population of many of our most problematic species. Pre-emergent herbicides are spread in granular form or sprayed onto turf or beds –  then soil moisture, rainfall or irrigation move the active ingredients into the top inch or so of soil. The herbicide binds with the soil particles and creates a barrier in the soil that kills the seeds as they germinate, preventing them from ever developing. It is important to do any cultivation, aeration or soil disturbance before applying the pre-emergent because disturbing the soil after application can weaken the barrier and allow breakthroughs. 

Controlling where possible with pre-emergent herbicides has some benefits over post-emergent options. It is typically a less expensive option. They never become visible and with combo fertilizer/herbicide products, the herbicide can be applied in one step of labor with the fertilizer application. Successful pre-emergent herbicide applications require knowledge of what weed pressures exist on the site, life cycles including when seeds in the soil will germinate and knowing which weeds will not be controlled by these applications. We deal with grassy weeds, broadleaf weeds and sedges and within those groups have annual, biennial and perennial weeds. Many annual weeds we deal with have seeds that can germinate throughout the year if moisture and temperatures are right. Many of the biennial and perennial weeds that give site managers constant problems regenerate from both new seeds and living in-ground plant parts that can reproduce new plants. Pre-emergent herbicides have no effect on these weeds regenerated from roots, stolons, rhizomes and other parts and will require post emergent herbicide controls. Many of our difficult to control weeds like dandelion, thistles and clovers regenerate new plants both ways.

Contact your Green Velvet representative to discuss the best product choice, timing and rate for dealing with your weed control issues.