A well-planned fertilization schedule is the key to a lush lawn. Learn when, how, and with what to fertilize your turf throughout the year.
Table of Contents6 sections
Table of Contents
The Importance of Fertilization
Your lawn needs nutrients to grow, regenerate, and resist stress. The three essential elements are nitrogen (N), phosphorus (P), and potassium (K), often indicated on fertilizer bags as an NPK ratio.
Understanding the NPK Ratio
- Nitrogen (N): Stimulates leaf growth and provides a deep green color
- Phosphorus (P): Promotes root development
- Potassium (K): Strengthens resistance to diseases, cold, and drought
The Fertilization Calendar
Spring (April-May)
The first application is crucial. Use a slow-release fertilizer with a balanced ratio (e.g., 20-5-10). Wait until the lawn has been mowed at least twice before applying to ensure it is actively growing.
Recommended dose: 0.5 kg of nitrogen per 100 m² (1 lb per 1000 sq ft)
Early Summer (June)
Apply a slow-release, high-nitrogen fertilizer to maintain color and density. Avoid fast-release fertilizers that can burn the lawn in hot weather.
Late Summer (August)
This is the time for a light application to prepare the lawn for its fall recovery. A balanced fertilizer helps the turf recover from summer stress.
Fall (September-October)
The fall application is the most important one of the year. Use a potassium-rich fertilizer (e.g., 10-5-20) to:
- Strengthen roots before winter
- Improve frost resistance
- Promote a quick green-up the following spring
Late Fall (November)
A final application of a fast-release, high-nitrogen "winterizer" fertilizer allows the grass to store reserves for the winter. Apply just before the first hard frost.
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Organic vs. Synthetic Fertilizers
Organic Fertilizers
- Slow and steady release
- Improve soil structure over the long term
- Lower risk of burning
- More environmentally friendly
Synthetic Fertilizers
- Faster, more visible results
- More precise dosage
- Generally lower cost
- Require watering after application
Application Tips
- Calibrate your spreader: follow the manufacturer's instructions for the correct setting
- Apply in a criss-cross pattern: go over the lawn once in one direction, then again perpendicularly for even coverage
- Water afterwards: a light watering helps the fertilizer penetrate the soil
- Avoid windy days: for an even distribution
- Never fertilize a dormant or drought-stressed lawn
Signs of a Nutrient Deficiency
- General yellowing: lack of nitrogen
- Slow growth and weak roots: lack of phosphorus
- Brown leaf edges: lack of potassium
- Pale green color between veins: lack of iron
LawnFan automatically calculates your fertilization needs based on your grass type, climate zone, and application history.