Semera®

What is Semera used for?

Semera is a broad spectrum herbicide and algaecide used to treat a wide variety of floating or submerged weeds plus algae.

What is the active ingredient?

The active ingredient is flumioxazin.

How to apply Semera herbicide?

Mix the liquid form with water in a sprayer or dissolve granules in water and spray over where the weeds are.

Is granular or liquid better?

Granular Semera can be sprinkled around dock areas for treating lake weeds. If treating watermeal, granular or liquid forms are best mixed with water and sprayed, so liquid is easier.

How does Semera compare to Clipper?

Semera has the same active ingredient in the same quantity as Clipper!

Is Semera safe for fish and wildlife?

Semera is EPA approved for aquatic use. It is safe to use with the fish, frogs, turtles, etc. in the water as well as the animals that come visit.

Will Semera kill duckweed or watermeal?

Yes! Semera will kill a large variety of floating weeds (including watermeal), submerged weeds, and algae.

When should I apply Semera?

For best results, apply Semera early in the morning when the pH of the water is naturally lower. Apply Semera when the water temperature is 60° F or warmer and the weeds are actively growing.

When will I see results after applying Semera?

You’ll see results on floating weeds or algae in 7-14 days and submerged weeds in 17-21 days.

Read all labels for complete instructions before applying products.

Weed identification

Our recommendations:

Submerged weed control

Floating weed control

How to apply

• Use the Tormada product application boat for easy application (for submerged weeds)
• Dilute (dissolve first if using granules) with tap water, and evenly spray the surface over the plants
  • Dilute 1 oz. in 1 gallon of water
  • 1 oz. = 3 Tbsp. + 1 tsp. of granules
• If using with a surfactant, dilute (dissolve first if using granules) products with tap water, and evenly spray the surface over the plants entirely
  • Dilute 1 oz. Semera and 1 oz. of surfactant in 1 gallon of water
  • 1 oz. = 3 Tbsp. + 1 tsp. of granules

When to apply

• Apply on a sunny, calm day when the water temperature is 60° F or warmer
• Treat early in the morning, and when plants are actively growing and near the surface of the water
• May re-treat every 7-14 days or when there is new growth

Other tips

• Application rates based on a 1 ft. average depth, areas with dense growth may require a higher rate to be used
• Mix with surfactant for floating and emergent plants

Semera WDG Label

Semera WDG SDS

Semera SC Label

Semera SC SDS

Flumigard Label

Flumigard SDS

Flumigard SC Label

Flumigard SC SDS

Aquatic herbicides water use restrictions according to label:

• Swimming: 0 days
• Drinking water: 0 days
• Domestic uses: 0 days
• Fish consumption: 0 days
• Irrigation for food/crop: 5 days
• Irrigation for turn/ornamental: 5 days
• Livestock watering: 0 days

FREE shipping on orders $99+

Orders $98.99 or less will be charged $12.95.

Orders are usually shipped within one day by a ground carrier.

U.S. shipping only.

Certain regulations apply for shipping to AK, CA, CT, DE, HI, ME, MA, NJ, NY, VT, WA, DC. Please contact us if you live in one of these states: 1-877-428-8898.