LD - I'm not one to argue with success. Your treatment method may work well, though relatively labor intensive.

A lot depends upon how quickly you apply the herbicide solution to the cut cattails and what concentration-mix was utilized (presumably of glyphosate).

In general, one may use a relatively high dilution-ratio when conducting full-coverage applications to uncut cattails (ex. 1 oz/gal.). Alternately, treatments applied to cut-surfaces need to be done quickly after cutting, and with lower dilution-ratios (higher concentrations - ex 1:1 ~ herbicide:water).

With virtually all systemic herbicides (Rodeo, Aquamaster, etc.), good results usually depend upon the plant's absorption of a sufficient amount of herbicide into its vascular system; whether applied at low concentrations over a large absorptive surface area or high concentrations to a small "cut" surface.

Your post wasn't considered misinformation. It may indeed be a very viable option for those who have moderate levels of infestations and don't want the unsightly appearance presented by a lot of dead cattail debris.

On the other hand, the labor to cut and remove a cattail biomass (ahead of a treatment) might be wasted if the follow-up herbicide treatment was not applied at a sufficient concentration.

BTW: both treatment methods should include a surfactant/wetting agent in the mixture.

Kelly Duffie
Cypress, TX