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When to Spray Pastures for Weed Control Full Guide of 2023

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when is the best time to spray pastures for weedsLet’s grab some weed & feed for your pastures, friend. Summer’s heat has your grazing grounds growing weeds faster than your cattle can mow the grass. But have no fear – with the right know-how, you’ll keep your fields fit for livestock in no time.

Though tempting, holding off until autumn leaves you losing the weed war. Early summer’s prime time to act while weeds are young and less hardy against herbicide. Consult your local extension office to ID specific species, then choose systemic herbicides to knock ’em out at the roots.

With a custom spray plan in hand, you’ll keep your pasture – and profits – growing strong. So scout your acreage, map problem areas, and take aim at weeds now before they take over.

Healthy grass makes healthy cattle and a healthy bottom line.

Key Takeaways

  • Scout pastures in early spring, late winter, and midsummer to identify weeds and note densities and problem areas.
  • Match herbicide to the species and growth stage.
  • Rotate livestock before seedheads emerge to prevent spreading.
  • Timely scouting and matched remedies transform weedy plots into pastoral paradises.

Weed Identification and Herbicide Selection

Weed Identification and Herbicide Selection
You’ll want to inventory your pastures in early fall and adjust grazing pressure. Identify target weeds and match herbicide selection and application timing to the species and growth stages present. Walk through each pasture and note weed density, problematic areas, and evaluate overall forage stand density.

Adjust livestock pressure to avoid overgrazed areas where weeds thrive. Identify key weeds and determine if they are annual, biennial, or perennial in order to select the proper herbicide. Read labels thoroughly, choosing products labeled for the target weeds and registered for use in pasture.

Match herbicide rates to weed size and growth stage. Select the right product and time the application to weed growth for effective control.

Common Toxic and Noxious Weeds

Common Toxic and Noxious Weeds
Watch out for those pesky jimsonweeds, thistles ‘n such when ya mosey through the pasture, or your cattle could get mighty ornery after snackin’ on ’em.

Keep an eye peeled for poison hemlock’s ferny leaves and purple blotches.

Scout early for multiflora rose, now a certified noxious weed in many states.

Pigweeds like Palmer amaranth can quickly take over an under-grazed pasture.

Proper identification is crucial to control those bad boys before they spread their toxic seeds all over the place.

And don’t forget to walk the fence lines where pesky thistles and such like to hunker down.

Keepin’ up with those sneaky weeds takes some know-how and elbow grease, but payoff is healthier, happier cattle and pastures.

Forage Crops Herbicides Application

Forage Crops Herbicides Application
When selecting herbicides for pastures, match the product’s timing, rate, and spectrum to target weeds at their most susceptible growth stage. Know weed lifecycles and their timing of emergence. Time applications for during or just prior to weed seed germination.

Assess weed growth stages and spray weeds when small and actively growing. Tank-mix herbicides with different modes of action for broader spectrum control. Spot spray weeds using a handheld sprayer. Promote dense forage stands through fertility, proper cutting height, and stand renovation.

Time herbicide applications to avoid crop injury. Consider herbicide persistence and rotational restrictions. Implement cultural practices first, then use herbicides judiciously as needed for effective integrated weed management.

Identify the Weeds

Identify the Weeds
Before choosing an herbicide, carefully identify the specific weeds infesting your pastures so you can select the right product and application timing.

  1. Walk your pastures in early spring, late winter, and mid-summer to make a list of all weed species present.
  2. Note aggressive weeds like broadleaf plantain, musk thistle, multiflora rose, curly dock, and purple loosestrife.
  3. Differentiate annual, biennial, and perennial weeds since their life cycles dictate control timing.
  4. Consider pre-emergent herbicides for early spring weeds; avoid summer spraying of perennials.
  5. Rotate grazing animals before seedheads emerge to prevent spreading.

Knowing the weed species on your land allows matching the herbicide mode of action and application timing to target them most effectively. Proper identification and a customized plan are key for optimal pasture weed management.

Seasonal Applications

Seasonal Applications
You’ll wanna target those rascally biennials in autumn once their leaves emerge and the weather’s still warm enough for the herbicides to be absorbed, lest those buggers go to seed come spring.

The ideal time for pasture spraying depends on the types of weeds present and their growth stages.

Weed Type Optimal Spray Window
Annuals Early spring or fall when small
Biennials Fall rosette stage before winter
Perennials Early fall with active growth

When selecting herbicides, match timing to the product’s strength on your weed targets. Consult labels for specifics on growth stages, adjuvants, rates, and grazing restrictions.

With a bit of planning and proper execution, you’ll keep those pesky weeds at bay and your pastures prancing.

Can You Spray Pasture for Weeds in Summer?

Can You Spray Pasture for Weeds in Summer
During the summer months, herbicide application on pasture forages requires careful consideration of growth stage and environmental conditions to achieve efficacy. Target spot spraying, rather than broadcast application, can help minimize herbicide usage while controlling key weed species.

Monitor pastures to determine the following:

  1. Competitive effects of weeds on forage quality and yield
  2. Adequate summer rainfall for herbicide absorption
  3. Proper weed growth stage for herbicide timing
  4. Any label restrictions on hay harvest interval after spraying
  5. Options to harvest as silage if spraying late in the season

Careful observation, timing, and selective herbicide use let summer spraying strengthen pasture quality and productivity while following label guidelines.

Applying Herbicide

Applying Herbicide
You’ve made great progress controlling summer weeds. Now, focus on applying herbicide at the optimal time for your target weeds. Regularly scout pastures, estimate weed densities, and assess previous control efforts.

This helps determine timing and herbicide selection. Match application timing and herbicide mode of action to the weed growth stage for best results. Adjust applications based on scouting. With a plan targeting problem weeds, you’ll gain control.

Rotate Your Grazing Animals

Rotate Your Grazing Animals
Rotate your grazing animals.

Rotating your grazing animals helps reduce pressure on any one area, allowing pasture plants to recover and outcompete weeds. By moving livestock between paddocks and avoiding overgrazing, you give your forages a rest period to regrow thicker and crowd out opportunistic weeds.

This also prevents selective grazing, where animals repeatedly graze preferred plants while ignoring weeds. Work grazing rotations so each paddock has adequate recovery before animals return. Moving animals when weeds are still small interrupts seed production and the lifecycle of persistent pests like thistles.

Rest also supports root growth for drought tolerance. Adjusting grazing pressure along with other practices like fertility management, timely mowing, and renovating thin stands delivers integrated control that minimizes reliance on herbicides.

With a little planning, you can leverage grazing patterns and promote healthy, weed-resistant pastures.

Frequently Asked Questions (FAQs)

How long do I need to keep livestock off pasture after spraying weeds?

You’d be wise to wait the full label-recommended livestock grazing interval when spraying weeds. Though tempting to save a few days, rushing livestock back could prove far costlier in the long run.

Is it okay to spray pastures while pregnant cows are grazing?

You shouldn’t spray pastures while pregnant cows are grazing. Some herbicides can be harmful to fetuses and nursing calves. Wait until cows are moved to another pasture before spraying weeds. Hand spot spraying is safer if cows must remain.

Monitor weeds and focus on cultural practices like fertility and grazing management first.

Do I need a special license or permit to buy and apply pasture herbicides?

No, you do not need a special license or permit to buy and apply approved herbicides on your own pastures following label directions. Focus on proper product selection, timing, technique, and safety precautions for effective control.

What spraying equipment (nozzles, pumps, etc.) works best for pasture weed control?

Use a backpack or handheld sprayer with flat fan nozzles to evenly apply herbicides at low pressures. Regularly check and calibrate the spray pattern to ensure you get adequate weed coverage and avoid drift onto sensitive areas.

How soon after rain can I spray weeds for best results?

Spray weeds 1-2 days after rain when foliage is clean and soil is moist for best herbicide uptake. Avoid runoff from heavy rain. Let plants dry if wet; it’s ideal to spray weeds in the morning under calm conditions.


Although nursing weeds may seem fetching at first, timely interventions can nurture lush pastures. By scouting fields during opportune seasons and judiciously applying herbicides, you’ll soon be reveling in the fruits of your labor – thriving stands with nary an unwelcome guest.

So monitor growing conditions, match remedies to rogues, and spray at the genesis of infestations. Little deeds done early prevent bigger headaches, transforming pestilent plots into pastoral paradises.

When is the best time to spray pastures for weeds? As soon as interlopers rear their heads.

Avatar for Mutasim Sweileh

Mutasim Sweileh

Mutasim is a published author and software engineer and agriculture expert from the US. To date, he has helped thousands of people make their yards lush and thick.