Whack-a-Weed: How to Battle the Outbreak

October boldly arrived with record rain, bringing nearly half of the North Valley’s normal annual rainfall in just one month. Plants are enjoying the surge of moisture. Unfortunately, weeds are thriving too.

Weeds are very opportunistic. Some can remain dormant for months. A few good rains, followed by sunny days, and suddenly we’re in the midst of an ongoing outbreak that has everyone playing whack-a-mole with pesky plants.

So what can you do?

In a previous article, I mentioned the benefits of applying a pre-emergent twice per year. This provides a foundation for consistent weed management. An application in June or July would typically mitigate fall weed issues. Unfortunately this year, the sheer volume of rain reduced its effectiveness.

Three strategies are needed:

Prevention Annual weeds reproduce from seeds. Pre-emergent herbicides kill germinating seeds, but not established plants.

Mechanical Removal Cut, pull, or hoe weeds before they go to seed. Once they set seed, removing them can spread more seed. And the longer you wait, the more difficult they will be to eliminate.

Post-emergent Treatment Herbicides like Roundup kill weeds that are actively growing.

No single strategy will be effective in the current onslaught. Some weeds are resistant to common post-emergent herbicides and require a type-specific herbicide or manual removal. Pulling weeds out by the roots is highly effective, but also labor intensive and can require daily attention in times like these. A combination of these two approaches is your best option for now.

Fortunately, this is a temporary situation. This weed infestation will recede as we dry out—assuming we do.