Prowl H 2 O


Prowl ® H 2 O delivers excellent residual control of annual grasses and select broadleaf weeds, now in a unique water-based formulation.

  • Prowl H 2 O offers the same great weed control as original Prowl, but now with less equipment staining and reduced odour.
  • The active ingredient is microencapsulated and suspended in a water-based formulation.
  • Flexible tank-mix options and application timings make it a good fit for many weed control programs for conventional and glyphosate-tolerant corn and soybeans.

How it works

  • Prowl H 2 O stops weeds as they are trying to emerge in your field.
  • It can be sprayed on emerged corn without worry about crop injury as it is not absorbed by any green tissue.
  • Will not control weeds that have already emerged but will keep weeds from coming back into a clean field.
  • Prowl H 2 O is used in a pre-plant application prior to planting soybeans, for early season residual control of key grass and broadleaf weeds.

When to apply

For Corn

  • Prowl H 2 O has an exceptionally wide window of application for maximum flexibility.
  • Can be applied with various tank-mix partners anytime after corn is planted up to the 4-leaf stage for outstanding grass control with excellent crop safety.
  • Can be applied in a liquid-fertilizer carrier as a replacement for water for pre-emergence applications.
  • Plant corn AT LEAST 4 cm deep to ensure good seed coverage.
Crop or weed type Stage
Corn Prowl H 2 O + Atrazine – Pre-emergence to 4-leaf stage
Prowl H 2 O + Banvel ® II – Pre-emergence to 4 leaf stage
Prowl H 2 O + Marksman ® – Pre-emergence to 4-leaf stage
Prowl H 2 O + Accent® + Banvel II – Spike to 3-leaf stage
Prowl H 2 O + Glyphosate – Pre-emergence to 4-leaf stage
Prowl H 2 O + Marksman + Glyphosate – Post-emergence at 1 to 4-leaf stage of glyphosate tolerant corn only
Broadleaf weeds Pre-emergence
Grassy weeds Pre-emergence

For Soybeans

  • Apply as an early pre-plant surface application.

For Dry Bulb Onions

  • Prowl H 2 O herbicide can be applied at the loop and 2 true leaf stage of crop development.
  • Uniformly apply the recommended rate of Prowl H 2 O herbicide in 100 L/acre or more of water by ground equipment.
  • Prowl H 2 O herbicide treatments will NOT control emerged weeds.
  • Make sure to control existing weeds before applying Prowl H 2 O herbicide.
  • Prowl H 2 O herbicide treatments are most effective in controlling weeds when adequate rainfall or overhead irrigation is received within 7 days after application.

How much to apply

  • Whether on its own or as a Prowl H 2 O tank-mix program, Prowl H 2 O is easy to apply.
  • Use at a rate of 10 gallons of spray solution per acre when applying to corn fields.

Corn Tank-Mix Application Rates

Tank-Mix Partner Rates
Prowl H 2 O Alone Prowl H 2 O -1.5 L/ac (3.7 L/ha)
Prowl H 2 O + Atrazine Prowl H 2 O – 1.5 L/acre (3.7 L/ha)
Atrazine – 1.25 L/acre (3.1 L/ha)
Prowl H 2 O + Banvel ® II Prowl H 2 O – 1.5 L/ac (3.7 L/ha)
Banvel II – 0.243 – 0.5 L/acre (0.6 – 1.25 L/ha)
Prowl H 2 O + Marksman ® Prowl H 2 O – 1.5 L/acre (3.7 L/ha)
Marksman - 1.5 - 1.8 L/ac (3.7 - 4.5 L/ha)
Prowl H 2 O + Marksman + Glyphosate*

Prowl H 2 O - 0.89 L/acre (2.2 L/ha)

Marksman - 1.0 L/acre (2.5 L/ha)

Glyphosate* - 360 g ae/L equivalent 2.5 L/ha (2.5 L/ha)

Prowl H 2 O + Accent + Banvel II Prowl H 2 O – 0.89 L/acre (2.2 L/ha)
Accent - 6.76 g/acre (16.7 g/ha)
Banvel II – 0.253 L/acre (0.625 L/ha)
Prowl H 2 O + Glyphosate* Prowl H 2 O – 1.5 L/acre (3.7 L/ha)
Glyphosate* - 360 g ae/ac (900 g ae/ha)

*For use on fields planted with Roundup Ready Corn. A rate of 360 g ae/ac is equivalent to 0.67 L/ac of Roundup WeatherMax ® (540 g/L) or 1 L/ac of Roundup Original ® (360 g/L). Check the label rate of your glyphosate formulation to confirm.

Mixing Instructions

  1. Fill the tank one-half to three-quarters full with clean water and agitate.
  2. Add tank-mix ingredients according to instructions listed below.
  3. After complete mixing, add PROWL H 2 O to the tank.
  4. When adding Accent plus BANVEL II, ensure that the tank-mix is well mixed and in suspension, then add a recommended non-ionic surfactant such as Citowett Plus, Agral or Ag-Surf to the tank-mix.
  5. Fill the remainder of the tank with water while agitating.
  6. Maintain continuous agitation while adding herbicides and until spraying is complete. If spray mixture is allowed to settle for any period of time, thorough agitation is essential to re-suspend the mixture before spraying is resumed.


Note: Do not apply PROWL H 2 O herbicide post-emergence in liquid fertilizers. Apply post-emergence applications in water only.

Tank-mix ingredients are to be added in the following order:

  • Wettable Powder, Dry Flowable or Water Dispersible Granule Formulations: When using water as a carrier, add the dry material to the partially filled tank while agitating. If applying with liquid fertilizer, make a slurry of the wettable powder in water (1 part WP to 2 parts water), before adding liquid fertilizer in spray tank. Slowly add the slurry into the partially filled tank while agitating.
  • Liquid formulations: Add the liquid to the partially filled tank while agitating.
  • Emulsifiable Concentrate (EC) formulations: Add the EC to the partially filled tank while agitating.
  • Solution formulations: Add the solution to the partially filled tank while agitating.
  • After complete mixing, add PROWL H 2 O herbicide to the partially filled tank while agitating.

For Soybeans

TIMING RATE OF PROWL H 2 O

Early pre-plant surface application.

Ground application only.

0.89 L/ac (2.2 L/ha) - plus glyphosate**

**Consult the glyphosate label for use rates

For Dry Bulb Onions on Muck Soils

TIMING RATE OF PROWL H 2 O
Loop stage of onion growth 2.67 L/ac (6.6 L/ha)
2 true leaf stage of onion growth 2.67 L/ac (6.6 L/ha)


Application at both growth stages is required for season-long control.


For Dry Bulb Onions on Mineral Soils

TIMING RATE OF PROWL H 2 O
Apply as a foliar application at the 2-6 true leaf stage of onion.  Ground application only. 0.89 - 1.34 L/ac (2.2 - 3.3 L/ha)

Application tips

For field corn

Uniformly apply with properly calibrated ground equipment using a minimum of 200 L water/ha.
Use a properly calibrated low-pressure (138 kPa to 276 kPa) sprayer equipped with 80o or 110o flat fan nozzles to achieve uniform spray distribution and minimize drift. Keep the by-pass line on or near the bottom of the tank to minimize foaming. Nozzle screens must be no finer than 50 mesh.


For soybeans

Uniformly apply with properly calibrated ground equipment.  The tank mix should be applied prior to planting soybeans in no-till or reduced tillage situations.  Soybeans should be planted at least 5 cm deep.  Adequate soil moisture is required for optimum activity.

For dry bulb onions

Apply as a foliar application at the 2-6 true-leaf stage.  Apply in 250 L water/ha by ground application only. Maximum of 2 applications per year.

Tank mixes

If you have a specific weeds that are of a concern, use one of the following tank-mix recommendations with PROWL H 2 O to assist you.

Prowl H 2 O + Atrazine (Aatrex Liquid 480, Atrazine 480)

Pre-Emergent – after planting and before weeds and crop emerge
Post Emergent Application – before 2 - leaf stage of annual grasses and up to the 4 leaf stage of corn
Grasses Barnyard grass
Fall panicum
Green foxtail
Yellow foxtail
Crab grass (large and smooth)*
Broadleaf Weeds Lamb’s-quarters**
Redroot pigweed**
Ragweed
Smartweed
Velvetleaf***
Main Feature Great performance on a broad spectrum of weeds at a low cost per acre. Best value.

*Pre-emergence applications only
**Controls triazine-resistant biotypes
***Early post-emergent application only up to the 3-leaf stage of corn

Always refer to the labels for complete product and application information

Prowl H 2 O + Banvel ® II

Pre-Emergent – after planting, before weeds or crop emerge
Post Emergent Application - before 2 - leaf stage of annual grasses
Grasses Barnyard grass*
Crabgrass (large and smooth)**
Fall panicum**
Green foxtail
Broadleaf Weeds Lamb’s-quarters***
Redroot pigweed***
Ragweed
Velvetleaf
Main Feature When ragweed, velvetleaf and triazine-resistant weeds are major problems.

*Post-emergence application provides partial control and reduces competition.
**Pre-emergence application only
***Controls triazine-resistant biotypes

Always refer to the labels for complete product and application information

Prowl H 2 O + Marksman ®

Pre-Emergent – after planting, before weeds or crop emerge
Post Emergent Application – before the 2-leaf stage of annual grasses
Grasses Barnyard grass*
Crabgrass (large and smooth)*
Fall panicum**
Green foxtail
Old Witchgrass
Broadleaf Weeds Lamb’s-quarters*, ***
Redroot pigweed***
Ragweed
Velvetleaf****
Main Feature Excellent treatment for heavy infestations of ragweed, velvetleaf and triazine-resistant weeds, with residual activity for later flushes.

*Post-emergence application provides partial control and reduces competition
**Pre-emergence application only
***Controls triazine-resistant biotypes
****Pre-emergence application provides partial control and reduces competition from this weed

Always refer to the labels for complete product and application information


Prowl H 2 O + Marskman + Glyphosate

Post Emergent Application - at the 1 to 4-leaf stage of glyphosate tolerant corn
Grasses Barnyard grass
Crabgrass (large and smooth)
Fall panicum**
Green foxtail
Broadleaf Weeds Lamb’s-quarters*
Redroot pigweed*
Ragweed (common)
Velvetleaf
Main Feature Excellent residual control of broadleaf weeds and annual grasses in glyphosate-tolerant corn.

*Includes triazine-resistant biotypes


Prowl H 2 O + Accent 75 DF + Banvel II

Post Emergent Application – at the 1-4 leaf stage of annual grasses, and from spike to 3 leaf stage of corn
Grasses Barnyard grass
Large Crabgrass*
Fall panicum
Green foxtail
Yellow foxtail*
Old Witchgrass
Broadleaf Weeds Bindweed, field
Buckwheat, tartary
Buckwheat, wild
Corn spurry
Cow cockle
Green smartweed
Lady's thumb
Lamb’s-quarters***
Mustard, Wild
Redroot pigweed***
Ragweed, common
Thistle, Canada**
Sow thistle, perennial**
Velvetleaf
Main Feature A post-emergent herbicide program with 3 modes of action that controls problem grass and broadleaf weeds from the spike to 3-leaf stage in corn. For grasses, application has to be made at the 1-4 leaf stage.

*Suppression only
**Top growth only
***Controls triazine-resistant biotypes

Always refer to the labels for complete product and application information

Weeds controlled


Broadleaf weeds controlled
Lamb’s-quarters*

Broadleaf weeds suppressed
Redroot pigweed*

Grassy weeds controlled
Barnyard grass
Green foxtail
Fall Panicum
Large crabgrass
Smooth crabgrass

*Includes triazine-resistant biotypes

Follow crops


Corn and soybeans can follow Prowl H 2 O in rotation.

Product specifications


Size (units x size): 2 x 8.9 L / 450 L
Product Article #: 59012420 / 59012481
PCP #: 29542
Ontario Classification #: 3
Gross Weight of Package (kg pkg/kg pallet): 24.8 / 897
Units/Pallet: 36 / 1
PTS - T/L (48 foot): 22
Warehouse Stack Height: 3 pallets
Heated Storage: Protect From Freezing
Flash Point: N/A
NFC Class: N/A
TDG Information: Not Regulated

Technology Sheets & Brochures

Where to Buy

Postal Code:

Distance (kms):

Find