Modifications of the "leaf spritz" technique for invasive plants

I first published in 2010 on the leaf spritz technique for "selective" control of invasive plants without affect on nearby "good" plants. The spray solution is a 15-20% solution of Garlon 4 in bark oil.

Invasive sunflower that was leaf-spritzed two weeks earlier.
I returned next year and found only three or four stems that had survived (or had been missed).

Since then I (and others) have used this technique for a wide variety of herbaceous plants. Many modifications can be done, depending on the species and the extent of the infestation. A later post provided more detail.

The original technique was to use a spray bottle to "treat" a few leaves in the upper part of the plant. However, some folks prefer to use a sponge to treat the leaves, and this technique also works. The advantage is that there is less chance of herbicide dripping onto "good" plants. This post shows how this modification works.

Buckthorn leaves that
had been spritzed
six days before.
The roots were also killed.

A major advantage of the "spritz" technique is that this is a "low-volume" treatment. Because the herbicide concentration is high, one doesn't need to "soak" the whole plant, as agriculturalists do. The fact that the herbicide is oil-based may have some significance here. (The original reason I was using this mixture was because I was doing basal bark treatment of woody plants, so I had the spray bottle in my hand. Why not try a few nearby herbaceous plants? Also, the leaf spritz technique does work for woody plants, as the buckthorn photo shows here.

Among other species that the leaf spritz works on are burdock, mullein, bird's foot trefoil, alfalfa, sunflower, and sweet clover (basal stem treatment).

I especially like this for dealing with large multi-stem patches of sweet clover that are too thick to dig quickly. I pull the stems back toward me, then lean down and spray the stem bases on the far side of the patch. Within three days they show distress and within six days they are dead!