How Often To Put Weed And Feed On Lawn: Timing is Key

Applying weed and feed to your lawn at the right time is crucial for effective weed control and healthy grass growth. Generally, you should apply weed and feed twice a year: once in the spring and again in the fall.

A healthy lawn is the pride of many homeowners. It’s a green carpet that enhances curb appeal and provides a space for relaxation and recreation. Achieving and maintaining this lushness often involves a combination of regular mowing, watering, and, crucially, fertilizing lawn and weed control frequency. One popular product that aims to tackle both is “weed and feed.” But the question that lingers for many is: How often to put weed and feed on lawn? The answer isn’t a simple one-size-fits-all. It depends on your specific lawn, the types of weeds present, your climate, and the particular weed and feed product you choose. However, a well-informed approach to its application can significantly improve your lawn’s health and appearance.

Deciphering Weed and Feed: What It Is and How It Works

Before diving into the “how often” aspect, let’s briefly touch on what weed and feed products are. These are typically granular or liquid lawn treatments that combine a herbicide (to kill weeds) with a fertilizer (to nourish the grass). The herbicide targets common lawn weeds, while the fertilizer provides essential nutrients to encourage grass growth. This dual-action approach offers convenience, allowing homeowners to fertilize and manage weeds in a single application.

The effectiveness of weed and feed hinges on the active ingredients. Herbicides in these products can be selective, meaning they target specific types of weeds (like broadleaf weeds such as dandelions and clover) while leaving grass unharmed. Others might be non-selective, though these are less common in residential lawn applications as they can damage desirable grass. The fertilizer component typically contains nitrogen, phosphorus, and potassium (N-P-K), along with other micronutrients, all vital for grass health.

When to Apply Weed and Feed: The Foundation of Success

The best time for weed and feed application is intrinsically linked to the life cycles of both your grass and the weeds you aim to control. Applying at the wrong time can render the product ineffective or even harmful.

Spring Weed and Feed: The Crucial First Step

Many lawn care experts agree that spring weed and feed is a vital part of the annual lawn care schedule. This is the time when many common lawn weeds begin their growth cycle.

Timing is Everything: The ideal window for applying spring weed and feed is when your grass has started to green up after winter dormancy, but before the weeds have set seed. This typically occurs when soil temperatures consistently reach above 55°F (13°C).
Why Spring? Applying in early to mid-spring allows the herbicide to target young, actively growing weeds. Fertilizing at this time also provides a much-needed boost to your grass as it emerges from winter and prepares for the warmer months.
Pre-Emergent vs. Post-Emergent: Some spring applications may include pre-emergent herbicides, which prevent weed seeds from germinating. If you’re using a product with a pre-emergent, timing is even more critical. You want to apply it before weed seeds have a chance to sprout. Post-emergent herbicides, on the other hand, kill existing weeds. Most weed and feed products contain post-emergent herbicides.

Fall Weed and Feed: Preparing for Dormancy and the Next Season

The second key application for weed and feed often falls in the autumn. Fall weed and feed plays a different but equally important role.

Autumn Advantage: In the fall, weeds are often still actively growing and absorbing nutrients as they prepare for winter. This makes them particularly susceptible to herbicides.
Strengthening Your Lawn: Fertilizing in the fall helps your grass roots to grow stronger and store energy, which is crucial for surviving the winter and emerging healthy in the spring. It also helps to thicken the turf, which can naturally suppress weed growth in the following season.
Timing for Fall: The optimal time for fall application is typically in early to mid-fall, after the peak heat of summer has passed but before the first hard frost. Similar to spring, consistent soil temperatures above 55°F (13°C) are ideal. This allows the grass to absorb the fertilizer and the herbicide to work effectively on any late-season weeds.

Frequency of Weed and Feed Application: Finding the Right Balance

Now, let’s address the core question: How often to put weed and feed on lawn? For most home lawns, applying weed and feed twice a year – once in spring and once in fall – is generally sufficient. This aligns with a typical lawn maintenance schedule that promotes consistent health and weed control.

Why Not More Often? Over-applying weed and feed can be detrimental.
- Herbicide Resistance: Frequent exposure to the same herbicides can lead to weeds developing resistance, making future treatments less effective.
- Grass Stress: Applying fertilizer too frequently or at the wrong times can burn your lawn, leading to yellowing or brown patches. Grass has specific nutrient needs, and over-fertilizing can disrupt its natural growth processes.
- Environmental Impact: Excess fertilizer can leach into waterways, causing environmental damage.
Exceptions and Considerations:
- Severe Weed Infestations: In cases of severe, persistent weed problems, a targeted, single application might be considered if recommended by a lawn care professional. However, this should be a last resort, and careful monitoring is essential.
- New Lawns: Newly seeded or sodded lawns have different needs. Typically, you should wait until the new grass has been mowed at least 3-4 times before applying any weed and feed products. This allows the young grass to establish a strong root system.
- Specific Product Instructions: Always read and follow the instructions on the product label. Different formulations may have different application recommendations.

Developing Your Lawn Care Schedule

Integrating weed and feed into your overall lawn care schedule ensures a systematic approach to lawn maintenance.

Seasonal Lawn Feeding and Weed Control

Your lawn maintenance schedule should be dynamic, adapting to the changing seasons and your lawn’s specific needs.

Spring (March – May):
- Early Spring: Light raking to remove debris.
- Mid-Spring: Apply spring weed and feed once soil temperatures are consistently above 55°F (13°C). This is also a good time for aeration if your soil is compacted.
- Late Spring: Continue regular mowing and watering. Spot treat any lingering weeds with targeted herbicides if necessary.
Summer (June – August):
- Focus on watering deeply and less frequently to encourage strong root growth.
- Mow at the higher end of the recommended height for your grass type to shade out weed seeds and conserve moisture.
- Avoid applying weed and feed during the heat of summer, as this can stress your grass. If you must fertilize, use a slow-release, non-herbicide fertilizer.
Fall (September – November):
- Early Fall: Apply fall weed and feed as temperatures begin to cool, but before the first hard frost. This is a critical period for fertilizing lawn to build root strength.
- Mid-Fall: Continue mowing and watering.
- Late Fall: A final mowing to remove any fallen leaves. Consider applying a winterizer fertilizer for enhanced winter protection.
Winter (December – February):
- Your lawn is dormant. Minimal activity is needed, mainly clearing snow or debris if necessary.

Factors Affecting the Best Time for Weed and Feed

Several environmental and lawn-specific factors influence the best time for weed and feed application.

Grass Type and Weed Predominance

The type of grass you have and the common weeds in your region play a significant role.

Cool-Season Grasses: These grasses (like fescue, rye, and bluegrass) thrive in cooler temperatures. They are best fertilized in the fall and spring. Spring weed and feed applications are effective when these grasses are actively growing and weeds are emerging.
Warm-Season Grasses: These grasses (like Bermuda, Zoysia, and St. Augustine) grow most actively in warm weather. For these, fertilizing lawn and weed control are best done in late spring or early summer, after they have fully greened up. Fall applications might not be as beneficial as the grass is beginning to go dormant.

Weed Life Cycles

Different weeds have different growth patterns.

Annual Weeds: These complete their life cycle in one year. Crabgrass is a common annual weed that germinates in the spring when soil temperatures rise. Pre-emergent herbicides are most effective against these when applied before germination.
Perennial Weeds: These live for many years. Dandelions and clover are examples. They are often best treated with post-emergent herbicides when they are actively growing, typically in spring or fall.

Weather Conditions

Extreme weather can impact application success.

Rainfall: Light to moderate rain after application can help activate the fertilizer and move the herbicide into the soil. However, heavy rainfall can wash the product away before it can be absorbed. Avoid application just before a heavy rain event.
Temperature: Avoid applying weed and feed when temperatures are expected to exceed 85°F (29°C), as this can stress or even kill your grass. The active ingredients can volatilize and damage desirable turf.
Wind: High winds can cause the granules to drift onto non-target areas like gardens, driveways, or water bodies. Apply on calm days.

Practical Tips for Applying Weed and Feed

To ensure the most effective and safe application of weed and feed, follow these practical tips:

Read the Label: This is the most important step. The product label contains specific instructions on application rates, timing, safety precautions, and target weeds.
Mow Before Applying: Mow your lawn a day or two before applying weed and feed. This removes excess foliage that might prevent the product from reaching the soil and weed crowns. However, ensure the grass blades are dry at the time of application.
Watering: Most weed and feed products require the lawn to be dry at the time of application. The dew should have evaporated. After application, watering may be recommended to help activate the product and wash granules off the grass blades. Check the label for specific watering instructions.
Avoid Application on New Seed or Sod: As mentioned, give new grass time to establish before applying.
Don’t Apply to Dormant Grass: Applying to dormant grass, especially in winter, is generally ineffective and can be harmful.
Calibrate Your Spreader: Use a broadcast spreader or drop spreader for even application. Ensure it’s calibrated correctly to apply the product at the recommended rate. Over-application can damage your lawn, while under-application will be ineffective.
Consider Spot Treatments: If you only have a few weeds, consider spot treating them with a targeted herbicide rather than applying weed and feed to the entire lawn. This reduces chemical use and potential stress on your grass.
Timing with Other Lawn Treatments: Avoid applying other fertilizers or pesticides close to a weed and feed application, as this can lead to over-fertilization or chemical burn.

Potential Drawbacks and Alternatives

While convenient, weed and feed products aren’t always the best solution for every lawn.

Herbicide Resistance: The overuse of the same herbicides can lead to resistance in weed populations.
Grass Sensitivity: Some grass types or individual grass plants may be sensitive to certain herbicides, especially during stressful conditions like heat or drought.
Environmental Concerns: The combination of chemicals, especially if over-applied, can pose risks to beneficial insects, pets, and the environment.
Timing Conflicts: Sometimes the ideal time for fertilizing your lawn doesn’t perfectly align with the ideal time for weed control.

Alternatives to Weed and Feed:

Separate Fertilization and Weed Control: Many lawn care professionals recommend applying fertilizer and herbicides separately. This allows for more precise timing for each task based on specific needs. For example, you might apply a targeted herbicide for broadleaf weeds in the spring and then a nitrogen-rich fertilizer in the fall.
Organic Lawn Care: This approach focuses on building healthy soil through compost and organic fertilizers, encouraging dense, healthy turf that can naturally outcompete weeds. Hand-pulling weeds is also a key component.
Post-Emergent Spot Treatments: For stubborn weeds that emerge throughout the season, using a liquid post-emergent herbicide applied directly to the weed is an effective and targeted approach.

Frequently Asked Questions (FAQ)

Q1: Can I put weed and feed down when it’s raining?
A1: No, you should not apply weed and feed when it is raining or when heavy rain is expected within 24-48 hours. Light dew on the grass is usually fine, and some products even recommend watering after application, but heavy rain can wash away the product before it has a chance to work. Always check the product label for specific watering instructions.

Q2: Is it okay to use weed and feed on a new lawn?
A2: Generally, no. New seed or sod needs time to establish a strong root system. Most weed and feed products should not be applied until the new grass has been mowed at least 3-4 times. Applying too early can damage or kill the young grass.

Q3: How long after applying weed and feed can I let my dog or kids play on the lawn?
A3: This depends on the specific product. Always consult the product label for safety instructions regarding pets and children. Typically, you’ll need to keep them off the lawn until the product has been watered in and the grass has dried completely.

Q4: What should I do if I applied weed and feed at the wrong time?
A4: If you applied at the wrong time (e.g., during extreme heat or just before heavy rain), monitor your lawn closely for signs of stress like yellowing or browning. If you applied too much, you may need to flush the lawn with water to dilute the product, but this can sometimes wash away the effectiveness. Consult the product label or a local lawn care expert for specific advice.

Q5: Can I use weed and feed on my flower beds or vegetable garden?
A5: Absolutely not. Weed and feed products are designed for lawns only. The herbicides can damage or kill ornamental plants, vegetables, and other desirable vegetation. Keep weed and feed applications strictly to your lawn area.

By carefully considering the timing, your specific lawn needs, and the product instructions, you can effectively use weed and feed as part of a comprehensive lawn maintenance schedule to achieve a healthier, greener, and weed-free lawn. Remember, consistency and informed application are the cornerstones of successful lawn care.