Zach Hendrix - CTO, Entrepreneur & Co-Founder at GreenPal | GreenPal
Proper fertilization is essential for maintaining a healthy lawn, whether you are doing it yourself or hiring a service. Fertilizing a lawn involves adding the necessary nutrients to the soil, much like taking a multivitamin to address deficiencies in the human body.
Understanding NPK ratios and conducting soil tests are crucial first steps. Soil testing helps identify nutrient deficiencies so that specific supplements can be applied rather than using generalized fertilizers. Home soil test kits available at garden centers or online provide simple means to determine nutrient levels, including nitrogen, phosphorus, and potassium (NPK), which are the main elements in lawn fertilizers.
Choosing the right fertilizer depends on understanding these nutrient levels and selecting a product with appropriate NPK values. For example, optimal parts per million (ppm) levels for nitrogen should be in the 20s, translating to about 70-100 pounds per acre. Phosphorus levels should range between 40 and 100 ppm, while potassium levels should exceed 250 ppm. A pH level of 6 to 7 is also ideal for grass growth.
Fertilizers come in various forms, with slow-release granular types often preferred over liquid sprays due to their ability to provide even coverage and reduce application frequency. "Gardenaholic recommends five fertilizer applications over the season," starting in mid-April until frost sets in.
Applying fertilizer requires caution to avoid overspreading, which can damage the lawn. Testing soil annually, preferably in spring, ensures an accurate fertilization strategy. Timing applications during early morning or late afternoon minimizes evaporation and enhances absorption.
Light rain following fertilization aids nutrient delivery but heavy rain risks washing away fertilizers. Signs of over-fertilization include yellowing grass and excessive weed growth; adjustments may involve reducing fertilizer use and increasing watering.
Ultimately, proper planning and execution—testing, applying nutrients as needed, and retesting—are key to achieving a lush green lawn.