Re: [gardeners] Miracle Grow Weed Preventer

Kay Lancaster (
Thu, 28 Jun 2001 12:59:35 -0700 (PDT)

On Wed, 27 Jun 2001 wrote:

> Active ingredient Trifluralin Alpha, Alpha,
> Alpha-Trifluoro-2,6-Dinitro-N,N-DIPROPYL-P-Toluidine    (C13H16F3N3O4)
> Called Scott's and the gals I talked with muddled through the label and were
> very confused as I am also.

Trifluralin is probably better known to us who grew up listening to
herbicide commercials as Treflan -- it's a pretty commonly used herbicide
in soybean production, for instance.

Basically, it works by blocking cell division, especially in young,
growing roots and it's a fairly low persistence herbicide.

> Can't be used after transplant, can be used up to 10 weeks prior to planting
> up to 1 day prior to transplanting.  So what's the difference between 1 day
> prior to transplant and after transplant?  It isn't going to dissipate in 24
> hours.

What they're trying to accomplish is to stop young weeds from growing
before planting, and hope that the crop isn't also damaged.  Mild Treflan
damage isn't terribly easy to spot for most people... the leaves and stems
may turn purplish, plants can be stunted, seedling stems swollen.

I'm assuming the particular formulation being used is designed to bind
to soil and thus lessen the chances of damaging the wrong plants.  Treflan
normally lasts a month or two in soil, so I wonder about applying it
several times... was he following label directions?

Here's a couple of starting points to learn about herbicide damage to
weeds and crops, and weed control methods:

more technical: