A: As long as those cattails are green and growing, you should spray them. Fall is actually an ideal time to treat pesky pond weeds because that's when the matured plants soak up nutrients through their leaves to prepare for the coming winter. They'll do the same thing with the herbicide—but it will cause their demise!
If you don't spray the cattails, they won't dry up and die. No, that would be too easy! When the weather gets cold, the leaves and stems will turn brown and dry up while the tuberous root systems in the soil below the surface lie dormant. Those tubers, having stored up energy all winter, will explode with new shoots and growth in the spring.
Plus, all that dead and dried up foliage will fall into your pond, adding decaying organics to the mix. That detritus—which is like fertilizer to pond weeds and algae—will cause an even bigger headache next year.
Spraying cattails now when they're still green is your best bet. Here's how we recommend you do it.
- Spray Growth: Using your tank sprayer, treat the cattails with Shoreline Defense with Treatment Booster Plus. Apply the herbicide, which has no usage restrictions, directly to all above-water foliage. The plant will draw it in through its leaves and die—roots and all.
- Spray Again: Wait about two weeks for the herbicide to kick in, and then repeat the process again to be sure you get that weed under control. This will be necessary in ponds with thick, abundant cattail growth.
- Remove Dead Foliage: As the cattails die, cut and rake out dead debris with your weed removal tools, like a weed cutter and pond rake. This will cut down on decomposing organics left in the pond, making it easier to get on top of any new growth in the spring.
Take some time during this late summer and fall to treat cattails. You'll be glad you did!