Keeping a lush, weed-free lawn requires diligent maintenance and care. While manual weeding can be effective for small infestations, severe weed problems often call for herbicide application. Using the proper herbicide and applying it correctly is crucial for getting rid of weeds without harming the grass.
This comprehensive guide will walk you through everything you need to know about applying herbicide to your lawn. We’ll cover herbicide types, safety precautions, application timing, equipment, techniques, and much more. With the right information and proper technique, you can effectively eliminate weeds and enjoy a pristine lawn.
Understanding Herbicides
Herbicides are chemical formulations designed to kill or inhibit the growth of unwanted plants, aka weeds. Several types of herbicides work in different ways:
Selective Herbicides
Selective herbicides target specific plants but do not affect others. For lawns, there are selective herbicides that kill broadleaf weeds like dandelions or crabgrass but do not harm the desired grass species. Using selective herbicides allows you to remove weeds without damaging the lawn.
Non-Selective Herbicides
Non-selective herbicides will kill almost any plant they come in contact with. These broad-spectrum herbicides are sometimes called total vegetation control. Glyphosate (Roundup) is a common example. Non-selective herbicides require careful application to avoid harming wanted plants and grass.
Pre-Emergent Herbicides
Pre-emergent herbicides create a chemical barrier to prevent weed seeds from germinating and emerging. Applying them before weeds sprout provides long-lasting control. This can reduce the need for selective herbicides later.
Post-Emergent Herbicides
Post-emergent herbicides target weeds after they have already germinated and broken through the soil surface. These offer more immediate control when weeds are already actively growing in the lawn.
Understanding the difference between pre- and post-emergent herbicides is key for proper timing and effectiveness.
Safety Precautions
When working with herbicides, it’s essential to exercise caution and follow all safety precautions. Here are some key tips:
- Wear protective gear – Gloves, long sleeves, closed toe shoes, goggles, and a mask are recommended when mixing and spraying herbicide. This prevents skin and eye irritation and inhalation hazards.
- Read all labels thoroughly – Follow all instructions for dosage, timing, mixing, application method, and precautions. Different herbicides have different requirements.
- Limit exposure – Avoid breathing in spray mist, and wash any accidental splashes immediately. Shower after you finish spraying.
- Use properly calibrated equipment – This ensures you apply the correct amount of herbicide for maximum effectiveness and safety.
- Store herbicides securely – Keep all herbicides in original containers, sealed tightly, and locked away from children and pets.
- Dispose of containers properly – Do not reuse empty herbicide containers. Dispose of them according to your local hazardous waste guidelines.
Following all safety best practices reduces risks and ensures herbicides work as intended.
Choosing the Right Herbicide
With many herbicide products available, it can be daunting to select the right one for your weed problems. Keep these key factors in mind when deciding on an herbicide:
Target Weeds
Identify the specific weeds in your lawn first. Look for selective herbicides labeled to control those target weeds. Some common lawn weeds and associated herbicides include:
- Broadleaf weeds (dandelions, clover, plantain) – 2,4-D, dicamba, MCPP
- Crabgrass – quinclorac, fenoxaprop
- Nutsedge – sulfentrazone, halosulfuron
Grass Type
Certain herbicides work better with specific grass species. Know your lawn’s grass type and choose an herbicide labeled as safe for use on those grasses. Cool season grasses like bluegrass, fescue, and ryegrass have different needs compared to warm season grasses like Bermuda, zoysia, or St. Augustine.
Application Schedule
Consider when you need weed control. Pre-emergent herbicides applied in early spring prevent weeds, while post-emergent products are more for actively growing weeds. There are also combination options providing both pre- and post-emergence activity.
Safety and Environmental Impact
Look for herbicides with lower toxicity if pets or children use the lawn. Also consider sustainability – some organic, natural herbicides have less environmental impact. Weigh safety, effectiveness, and your specific situation when selecting a product.
Application Timing
Timing is vital for herbicide effectiveness. Here are the optimal application windows:
Pre-Emergent Herbicides
Apply pre-emergent herbicides in early spring before soil temperatures reach 55-65°F. This is right before most annual weeds begin germinating. It creates a chemical barrier preventing seeds from sprouting. Timing varies by region – look for local guidance on soil temperature and average last frost dates.
Post-Emergent Herbicides
Post-emergent herbicides target actively growing weeds after they are visible above the soil. Apply when weeds are young, typically early to mid-spring. Established perennial weeds may need late summer or fall application as well. Weed identification and monitoring ensures proper timing.
Avoid Heat and Drought
Avoid applying herbicides during mid-day heat or drought conditions. Hot, dry weather makes it harder for plants to absorb the chemical. Early morning or evening applications when temperatures are cooler give the best results.
Also time applications for dry weather without rain in the forecast. Heavy rain right after application can wash away the herbicide before it is absorbed.
Proper timing takes some planning, but it ensures maximum weed control.
Application Methods
Herbicides can be applied using different techniques:
Liquid Spraying
The most common method is spraying a diluted liquid herbicide solution evenly over the lawn using a handheld or backpack sprayer. This offers precise application. Use spray nozzles that produce a fine mist to avoid runoff.
Granular Spreading
Some herbicides come in granular or pellet form. These are dispersed using push spreaders in a swath pattern. Granules provide extended residual activity as they slowly release herbicide. Even coverage is important.
Wiping
Wiping involves using a sponge, brush, or wick applicator to directly wipe herbicide solution onto weeds. This allows precise application to avoid harming grass. It is practical for spot treatment of scattered weeds.
Directed/Shielded Spraying
Using a shield around the spray nozzle allows you to target weeds growing near ornamentals or gardens. The shield blocks overspray onto desirable plants while directing herbicide right at the weeds.
Consider your specific needs, area size, and budget when choosing application methods.
Equipment for Herbicide Application
Having the proper equipment makes herbicide application much easier and helps ensure accuracy. Key tools include:
Protective Gear
Wear goggles, chemical-resistant gloves, long sleeves, pants, shoes, and a mask when spraying. This provides maximum safety for the applicator.
Sprayers
Choose pump-pressured backpack or handheld sprayers for larger lawns. Small areas can use simple pump spray bottles. Ensure sprayers have adjustable nozzles and pressure regulators.
Spreaders
Drop or rotary spreaders provide even distribution for granular herbicides. Models with metal gears and pneumatic tires work best.
Measuring Cups & Mixing Containers
Properly measure out herbicide concentrates before diluting. Use buckets or mixing containers specifically for herbicides. Avoid food containers.
Application Shields/Guards
Use shielded sprayers when treating weeds near ornamentals and gardens. This prevents herbicide contact with desired plants.
Having quality tools suitable for the area size makes herbicide application much more efficient. Investing in proper equipment saves time and frustration.
Preparing Your Lawn for Herbicide Application
Taking time to prepare the lawn first leads to better herbicide results:
- Mow the grass 3-4 days before spraying. This allows weeds to regrow and be more susceptible.
- Remove any leaves, debris, or yard waste covering weeds. This exposes them fully to the herbicide.
- Water 1-2 days prior if soil is dry. Weeds take up more spray solution with adequate soil moisture. But avoid overwatering.
- Plan for little to no rain immediately after application. Rain can wash away product before it absorbs.
- Time applications for cooler temperatures early or late in the day. Avoid hot midday heat.
- Identify problem weeds and select suitable herbicides before starting. Have all supplies and equipment ready to go.
- Read and follow all label instructions for the specific herbicide product.
Taking these preparatory steps sets up optimal conditions for your herbicide application.
Applying Herbicide to Your Lawn
Once you have selected your product and prepared the lawn, follow these steps for proper application:
1. Mix Herbicide Solution
Mix liquid concentrate with water in a separate container according to label directions. Measure concentrates carefully and use clean water. Only mix what you need for one application.
2. Calibrate Sprayer
Check that spray nozzles are clear and set to deliver the desired volume. Adjust pressure and test spray pattern before use.
3. Apply Herbicide
Uniformly spray the diluted herbicide over the entire lawn at the rate specified on the product label. Granular products use a spreader for even distribution. Keep a steady pace.
4. Check for Missed Patches
Look for uneven coverage or missed patches and go over them to prevent surviving weeds. Ensure you spray across the entire lawn area needing treatment.
5. Clean Equipment
Rinse sprayer with clean water after use and clean all equipment to remove herbicide residue buildup. Properly store and seal any unused product.
6. Let Sit
Avoid watering, mowing, or using the lawn for the timeframe listed on the herbicide label to allow maximum absorption and effectiveness.
With the proper process and steps, you can achieve uniform application for optimal weed control results.
Post-Application Care
Herbicide application is not the end – proper follow up care makes a difference:
- Wait the required days before mowing to allow herbicides to work fully.
- Adhere to any watering guidelines specified on the product label after application.
- Dispose of any leftover diluted herbicide solution – do not save or reuse it.
- Watch for herbicide symptoms like leaf yellowing as weeds die. This confirms product performance.
- Remove dead weeds after the waiting period with raking. This improves lawn appearance.
- Overseed bare spots where weeds die with new grass seed to fill in.
- Adjust future timing if application was too early or late based on weed survival.
- Let grass fully recover before stressing with additional products or heavy use.
Proper aftercare ensures your herbicide achieves maximum weed control with minimal lawn stress.
Common Mistakes to Avoid
While herbicides are effective when used correctly, several common mistakes lead to disappointing results:
- Using improper rates – Too little won’t control weeds, too much risks lawn injury.
- Spraying in windy conditions – This causes drift onto desirable plants.
- Applying during hot, dry weather – Plants can’t readily absorb the chemical.
- Allowing runoff during application – Not allowing the herbicide to stick to plants.
- Applying too early or late – Missing the weed growth stage targeted by the product.
- Failing to calibrate sprayers – Results in uneven and inaccurate application.
- Not following label directions – Ignoring specific product requirements.
- Mowing too soon before or after application – Reduces herbicide effectiveness.
- Allowing pets and children access too soon – Before treated areas are dry and safe.
Avoiding these common errors helps ensure your herbicide application goes smoothly and works as intended.
Dealing with Herbicide Resistance
When certain weeds no longer respond to an herbicide that previously controlled them, this means they have developed resistance. Overuse of a single mode of action allows weeds to adapt. There are several ways to overcome resistance:
- Rotate using herbicides with different modes of action – Do not repeatedly use the same active ingredient.
- Tank mix multiple herbicides together – Combining modes of action makes resistance less likely.
- Use non-chemical control occasionally – Methods like hand weeding, tillage, or mulching.
- Identify resistant weeds and treat while young – Smaller weeds are easier to control.
- Follow all label guidelines carefully – Using maximum rates and optimal timing.
- Consider replacing resistant turfgrass varieties – Some cultivars have better resistance genetics.
- Maintain healthy, vigorous grass – Thick turf crowds out potential weeds.
Careful herbicide rotation and integration of other control methods helps manage the development of herbicide-resistant weeds.
Monitoring and Reapplication
A single herbicide application provides temporary weed control. Monitoring your lawn and reapplying as needed prevents new weeds from invading:
- Scout for new weed growth 1-2 weeks after treatment. This checks product efficacy.
- Reapply post-emergent herbicides on two week intervals as weeds germinate.
- Reapply pre-emergent herbicides every 2-3 months through peak germination seasons.
- Adjust application timing if weeds are emerging sooner or later than expected.
- Identify areas of the lawn needing spot treatment vs whole lawn reapplication.
- Alternate herbicides with different modes of action between applications.
- Keep detailed logs of your applications and weed response.
Careful monitoring and properly timed reapplication provides season-long control with minimal weed breakthrough.
Alternative Weed Control Methods
While herbicides provide convenient and effective weed control, there are also some alternative options:
- Manual weeding works for small infestations. Use a dandelion puller tool to remove taproots.
- Maintain a taller mowing height – This helps grass outcompete weeds for light.
- Improve drainage in soggy areas prone to weeds. Aerating can help.
- Apply corn gluten meal in early spring – Provides natural pre-emergence control.
- Mulching open areas deprives germinating weeds of light. Use wood chips, gravel, or landscape fabric.
- Increase turf density by overseeding – Crowds out potential weed growth.
- For spot treatment, use boiling water, salt, or concentrated vinegar.
While more labor intensive, these organic weed control options are safe for kids and pets in the lawn.
Conclusion
Controlling lawn weeds with proper herbicide application takes some upfront effort – from product selection to application best practices. But the reward is a lush, weed-free lawn for enjoyment all season long.
Follow the tips in this guide to choose targeted herbicides, use proper timing for your weed problems, and employ the correct application techniques. Always exercise caution by wearing protective gear and following label directions.
With the right herbicide program and vigilant monitoring, you can rid your lawn of pesky weeds without using harsh chemicals. Your beautiful, green grass will be the envy of the neighborhood!
