How to Apply Lawn Fertilizer

A beautiful green lawn can greatly enhance the look of your yard and home. But achieving a lush lawn takes a bit of work, including proper mowing, watering, aerating and applying the right fertilizers. Fertilizing your lawn provides it with important nutrients that allow the grass to thrive. Learning how to properly apply lawn fertilizer can help you get the beautiful lawn you desire.

When to Apply Fertilizer

The timing of fertilizer application is important for optimal results. Here are the best times to fertilize your lawn:

  • Spring: Early spring, when grass first starts actively growing, is a great time for the first feeding of the year. This provides nutrients to help the lawn recover from winter dormancy. Aim to fertilize 4-6 weeks before the expected last spring frost.
  • Summer: Apply another round of fertilizer 6-8 weeks after the spring feeding. This will stimulate growth through the heat of summer.
  • Fall: Late summer to early fall is prime time for fertilizing cool season grasses like bluegrass and fescue. The nutrients help the grass store energy for winter and thrive the following spring.
  • Avoid winter: Fertilizing when grass growth has slowed down or stopped in cold weather provides little benefit. It can even damage the lawn if applied too late in fall after grass has hardened off.

Pay attention to seasonal timing for where you live. Work within the natural growth cycle of the grass species in your lawn.

Choosing a Fertilizer

Selecting the right type of fertilizer ensures your lawn gets the nutrients it needs. Consider the following factors:

  • Grass type: Formulations are tailored for cool season grasses like bluegrass versus warm season varieties like Bermuda.
  • Quick or slow release: Quick release fertilizers provide an immediate nutrient boost. Slow release options deliver nutrients over an extended time.
  • NPK ratios: NPK refers to nitrogen (N), phosphorus (P) and potassium (K), the primary nutrients. Aim for an NPK ratio tailored to your grass and season.
  • Organic or synthetic: Both have pros and cons. Synthetic fertilizers offer more control; organic options are slower release.

Consulting with your local garden center can help identify the ideal fertilizer for your needs. Provide details on your lawn like grass variety and current condition.

Common Fertilizer Types

Here are some of the most common options for lawn fertilizers:

  • Granular fertilizer – Pelletized fertilizer that spreads easily over the lawn. Available in quick and slow release versions.
  • Liquid fertilizer – Concentrated fertilizer that mixes with water for spray application. Offers immediate nutrient uptake.
  • Organic fertilizer – Made from plant, animal or mineral sources. Provides nutrients more slowly over time.
  • Weed and feed – Combination products that include lawn fertilizer along with weed killers. Offer convenience but can risk overapplying chemicals.

How Much to Apply

Check the label of your fertilizer product for recommended application rates. Most provide settings for different spreader types.

As a general rule of thumb:

  • Apply 1 lb of nitrogen per 1,000 sq ft of lawn space.
  • Slow release fertilizers call for around half this rate every 6-8 weeks.
  • Excess fertilizer can damage grass, so more is not better. Stick to rates on product labels.

A soil test can dial in exactly how much and what type of fertilizer your lawn needs. Your local extension service may offer low-cost testing.

Application Methods

Proper application technique ensures the fertilizer reaches your lawn, not sidewalks or streets. Options include:

Broadcast Spreader

Push and rotary broadcast spreaders efficiently cover large lawn areas. Follow tips for best results:

  • Calibrate spreader settings using manufacturer guidelines.
  • Use half rate going one direction, half the other direction for even coverage.
  • Avoid spreader overlaps that apply double fertilizer.
  • Sweep any stray fertilizer granules off hard surfaces onto lawn areas.

Drop Spreader

These spreaders drop fertilizer directly beneath, providing better control. Keep in mind:

  • Go slowly for uniform coverage.
  • Use narrower swath for small lawns.
  • Take care on slopes where fertilizer can shift to one side.

Liquid Fertilizer Sprayer

Sprayers use diluted liquid fertilizers. Pros and cons include:


  • Provide immediate nutrient availability.
  • Allow foliar feeding to bypass poor soil.
  • Reach lawn areas broadcast spreaders may miss.


  • Coverage requires multiple passes.
  • More potential for foliar burn compared to granular fertilizers.

Fertilizer Spikes

Spikes are driven into the ground in a grid pattern. Considerations:

  • Require more physical work than broadcasting.
  • Apply fertilizer below thatch layers for slow nutrient release.
  • Create concentrated fertilizer zones that can damage grass.

Select a spreader or sprayer suited for your lawn’s size and terrain. Make sure it provides uniform fertilizer distribution.

Lawn Prep Before Fertilizing

A bit of planning and prep helps fertilizer work most effectively:

  • Mow the lawn 3-4 days before fertilizing. This avoids removing nutrients along with clippings.
  • Irrigate thoroughly if the lawn is dry. Fertilizer needs water to dissolve and soak into soil.
  • Consider aerating compacted lawns first so fertilizer can better penetrate soil.
  • Control lawn weeds, which compete with grass for nutrients.
  • Clear fallen leaves and debris that can interfere with fertilizer reaching grass.

Taking these simple steps avoids wasting fertilizer and improves its availability to your lawn’s root zone.

Fertilizer Application Tips

Follow these tips for success when applying fertilizer:

  • Read and follow all label directions carefully.
  • Wear gloves and wash hands after use to avoid skin irritation.
  • Avoid inhaling dust by using a mask if needed.
  • Apply on a calm day to prevent granules blowing away.
  • Water after applying to move nutrients into soil, or apply before rain.
  • Sweep any fertilizer landing on hard surfaces back onto the lawn.
  • Follow label precautions for pets and kids entering treated lawn areas.

Careful fertilizer application minimizes waste, enhances safety, and ensures your lawn gets the nutrients it requires.

Signs Your Lawn Needs Fertilizer

How do you know when it’s time to fertilize the lawn? Look for these clues:

  • Loss of deep green color – Nitrogen deficiency shows as grass looking yellowed and pale.
  • Slow growth – Poor nutrient levels reduce shoot and root growth. Fertilizing stimulates active growth.
  • Thinning turf – Grass plants losing density is a sign of nutrient deficiencies stressing the lawn.
  • Poor recovery from traffic – Footprints and mower tracks lingering can indicate low fertility.
  • Weeds invading – Abundant weeds like dandelions signal the lawn is stressed and competitively weak.

Addressing these issues through proper fertilization helps rejuvenate lawn health and thickness.

Alternatives to Fertilizer

Besides standard fertilizers, consider these options:

  • Compost topdressing – Adds nutrients and organic matter while improving soil.
  • Liquid seaweed – Provides micronutrients, amino acids and growth promoters.
  • Microbial inoculants – Bacteria and mycorrhizal fungi enhance nutrient availability.
  • Humic acids – Aid nutrient uptake and counteract alkali soils.
  • Sulfur – Lowers soil pH for acidic loving plants.
  • Iron – Addresses iron chlorosis for stronger grass.

Combining traditional fertilizer with these supplements can enhance soil health and plant performance.

When to Stop Fertilizing

Knowing when to cease fertilizer applications for the season is also important:

  • Stop several weeks before expected first frost so grass hardens off properly.
  • Don’t fertilize during winter dormancy when grass is not actively growing.
  • Discontinue fertilizer if drought conditions develop and grass growth stops.
  • Avoid fertilizing near major holidays when grass will get heavy traffic.

End-of-season fertilizing can lead to disease problems, winter damage and wasted effort and expense.

Health and Environmental Considerations

Applying lawn fertilizers comes with some health and environmental cautions:

  • Keep children and pets off treated lawns until materials water in and dry.
  • Follow all label safety gear recommendations when applying fertilizer.
  • Irrigate immediately after fertilizing to minimize chemical runoff.
  • Sweep any granules landing on sidewalks, drives, etc back onto lawn areas.
  • Avoid fertilizing just before heavy rain that can wash chemicals into storm drains.

Careful fertilizer application keeps both your family and the environment safe.

FAQs About Fertilizer Application

Questions commonly arise when learning how to fertilize a lawn properly. Here are answers to some frequently asked questions:

Should I fertilize before or after mowing the lawn?

Apply fertilizer around 3-4 days after mowing. This minimizes removing nutrients along with grass clippings. Let the grass grow a bit before its next cut.

How soon after fertilizing should I water?

Ideally irrigate immediately after fertilizer application. This dissolves granules and moves nutrients into the soil before they have a chance to burn grass blades.

What’s the difference between quick and slow release fertilizers?

Quick release fertilizers provide a rapid nutrient boost but effects don’t last. Slow release options provide a slower, steady feeding over 6-8 weeks.

How do I calibrate my broadcast spreader?

Most have settings on the hopper that indicate roughly how fast fertilizer will flow at each number mark. But do a test run on concrete with marked areas to dial in speed and swath width.

Should I bag or mulch mow after fertilizing?

Mulch mowing is ideal. It returns grass clippings and the nutrients they contain back to the soil. Just make sure the lawn is dry before mowing.

When is the best time to aerate my lawn?

Core aerate in early fall or spring when grass is actively growing to maximize recovery and benefit. Avoid summer heat stress.

Following label directions and asking questions ensures you apply fertilizer effectively and safely.


Achieving a lush green lawn takes proper fertilization along with practices like mowing, irrigation and aerating. Learning how to apply lawn fertilizer correctly provides the nutrients grass needs to thrive without wasting product or causing environmental issues. Pay close attention to fertilizer timing based on the season, choosing an optimal formulation, following application rates, using proper techniques and equipment, and adhering to safety precautions. A beautiful lawn with minimal effort is possible when you fertilize skillfully. Robust grass with few weeds and a deep green color will have your neighbors asking what your secret is!