Broadleaf post-emergent herbicides are used to control weeds that are already visible above the soil. These products do not prevent weeds, they control existing plants. Correct product selection depends on:

Turf type
Weed maturity
Temperature
Application rate

Before You Spray (Always Say This First)

If the weed is visible, pre-emergent will not work
Turf must be actively growing, not stressed
Do not spray drought-stressed or heat-stressed turf
Follow the label exactly

GOOD · BETTER · BEST

✅ GOOD

Entry-Level Broadleaf Control

Products

2,4-D Amine, One way herbicide
3-D Foam (spot treat)
Trimec Southern, Three way herbicide

Typical Rate

1.0 – 1.5 oz per 1,000 sq ft

Timing and Technique

Post-emergent herbicides work best when applied early in the morning. Morning applications are preferred over afternoon or evening sprays for several reasons:

Leaf tissue is dry, allowing better herbicide contact
Plants are actively transpiring
Leaf pores are more receptive to herbicide uptake
Cooler temperatures reduce turf stress and drift

Avoid spraying during the heat of the day or late evening when uptake is reduced and stress is higher.

Spray Technique

Proper technique matters as much as product choice.

Keep the spray nozzle 12 -18 inches above the turf
Use a medium droplet size, not a fine mist
Pattern should be about the size of a dinner plate
Apply in a circular motion, not side-to-side
Goal is even coverage, not runoff

Over-application does not improve control and increases the risk of turf injury.

Key Reminder

Post-emergent herbicides work through leaf absorption, not the soil. Dry leaves, proper timing, and correct spray pattern are critical for consistent results.

Best practice:

Early morning, dry leaf, correct height, steady circular motion.

Spring and fall
Air temperatures 60 - 85°F
Best on young, actively growing weeds

Turf Sensitivity

Bermuda: Safe when actively growing
Zoysia: Generally safe, avoid stress
St. Augustine: Use caution, amine formulations only
Dormant turf: Poor results

Limits

Slower results
Limited on tough weeds
Weak on spurge, mallow, dollarweed
No sedge or grassy weed control

Counter explanation

“This works on small, common weeds. If they’re mature or stubborn, we’ll need to step up.”

✅ BETTER

Workhorse Broadleaf Control

Products

SpeedZone Southern (RUP)
Weed Free Zone
Q4 Plus
Blindside
Basagran T&O
Triclopyr (Brush & Stump)

Typical Rate

0.75 – 1.25 oz per 1,000 sq ft
(Blindside often lower)

Timing and Technique

Post-emergent herbicides work best when applied early in the morning. Morning applications are preferred over afternoon or evening sprays for several reasons:

Leaf tissue is dry, allowing better herbicide contact
Plants are actively transpiring
Leaf pores are more receptive to herbicide uptake
Cooler temperatures reduce turf stress and drift

Avoid spraying during the heat of the day or late evening when uptake is reduced and stress is higher.

Spray Technique

Proper technique matters as much as product choice.

Keep the spray nozzle 12 -18 inches above the turf
Use a medium droplet size, not a fine mist
Pattern should be about the size of a dinner plate
Apply in a circular motion, not side-to-side
Goal is even coverage, not runoff

Over-application does not improve control and increases the risk of turf injury.

Key Reminder

Post-emergent herbicides work through leaf absorption, not the soil. Dry leaves, proper timing, and correct spray pattern are critical for consistent results.

Spring through early summer
Fall clean-up
Faster visual burn-down than GOOD products

Turf Sensitivity

Bermuda: Safe when actively growing
Zoysia: Safe at label rates
St. Augustine:
- Use Southern-labeled products only
- Avoid ester formulations during heat
Heat caution:
- Ester products above 85 - 90°F can cause injury

Strengths

Faster knockdown
Broader weed spectrum
Better on spurge, mallow, dollarweed
Triclopyr adds woody and vine control

Counter explanation

“This gives quicker results and handles tougher weeds without jumping to specialty products.”

✅ BEST

Professional / Advanced Control

Products

Celsius
Celsius XTRA
MSM Turf
Southpaw
Telar XP
Katana
Vexis
Meso 4SC

Typical Rates (Low-Rate Products)

Celsius: 0.05 – 0.085 oz per 1,000 sq ft
MSM / Telar / Katana: grams or fractions of an ounce per acre
Meso 4SC: 0.15 – 0.3 oz per 1,000 sq ft

Timing and Technique

Post-emergent herbicides work best when applied early in the morning. Morning applications are preferred over afternoon or evening sprays for several reasons:

Leaf tissue is dry, allowing better herbicide contact
Plants are actively transpiring
Leaf pores are more receptive to herbicide uptake
Cooler temperatures reduce turf stress and drift

Avoid spraying during the heat of the day or late evening when uptake is reduced and stress is higher.

Spray Technique

Proper technique matters as much as product choice.

Keep the spray nozzle 12 -18 inches above the turf
Use a medium droplet size, not a fine mist
Pattern should be about the size of a dinner plate
Apply in a circular motion, not side-to-side
Goal is even coverage, not runoff

Over-application does not improve control and increases the risk of turf injury.

Key Reminder

Post-emergent herbicides work through leaf absorption, not the soil. Dry leaves, proper timing, and correct spray pattern are critical for consistent results.

Warm-season turf actively growing
Best in healthy turf
Often requires repeat applications

Turf Sensitivity (Very Important)

Bermuda: Excellent tolerance
Zoysia: Generally safe
St. Augustine:
- Celsius and Celsius XTRA only
- MSM, Telar, Katana NOT labeled
Cool-season turf: Label dependent

Key Training Point

These are not rescue sprays.
They work best when:

Rate is accurate
Turf type is correct
Expectations are realistic

Counter explanation

“These are professional products. They work extremely well, but the rate and turf type matter.”

Common Reasons Broadleaf Control Fails

Wrong product for turf type
Over-application
Spraying in heat or drought
Mature weeds requiring repeat applications
Poor mowing or irrigation practices

➡ Link: Lawn Care 101 BMP

Summary for Staff

GOOD: Cheap, simple, slower
BETTER: Faster, broader, most common choice
BEST: Professional, low-rate, highest control

Start at GOOD.

Move up only when needed.

POST‑EMERGENT HERBICIDE STUDY GUIDE