Writing an online answer for a question like “When should I fertilize my lawn?” is difficult, because Internet readers live in different parts of the country, if not the world.
Climate is a major factor in knowing when fertilizer needs to be added to your lawn, and climate factors change from one region to the next.
Fertilizing in Texas is not the same as fertilizing in Maine. Even in warm weather climates like California and Florida, fertilizer probably needs to be added at different times of the season.
Your Lawn and Sunlight
Beyond that, there are warm-season grasses and cool-season grasses, each of which that needs to be fertilized at different intervals.
Plants tend to grow when the amount of sunlight they receive tells them when to grow. This means that a certain type of grass is going to start growing on roughly the same day every year, but if that same type of grass is two states north, that same spring day further south is going to be longer, and therefore growing season changes with location of the same species of grass.
Keep in mind that a succession of overcast days, or a lot of stormy days, means less sunlight for your plants, so bad weather with less sunlight means your grass is likely to wait to grow.
In the end, your lawn is going to decide when to start growing on its own time, according to its own bio-rhythms, so don’t get ahead of yourself and add nitrogen, when your lawn doesn’t appear interested in growing.
With all of that in mind, I’ll try to give an overview about when you should fertilize your grass, according to the cool-weather grass and warm-weather grass you’ll be planting.
Learn when lawn grass begins to grow in your region of the country, so you’ll be able to nail down exactly when you should fertilize your lawn.
Cool Season Grass Fertilizer
Cool-weather grass has two growing seasons: in the spring and the fall, when weather is temperate.
Even in the summer, cool-weather lawn grass stops growing, because the heat waves of the late summer are harsh ont he grass.
For cool weather lawns in the northern part of the United States, you’ll want to fertilize when grass shows signs of returning from the yearly winter dormant period.
Warm Season Grass Fertilizer
The warm-weather lawn grasses tend to be used in the southern part of the United States. These grasses are best to fertilize when grass starts to show its green in the spring.
Add lots of nitrogen to the soil at this point. In the latter stages of the summer, fertilize your lawn again, but with a smaller amount of nitrogen then.
When Not to Fertilize Your Lawn
Don’t fertilize when you’re have a drought or heat wave. When you apply fertilizer, it needs water to soak into the soil.
If it doesn’t soak into the soil, fertilizer can burn your lawn, making the drought worse. If you do apply fertilizers during a dry spell, bite the bullet and water your lawn well a couple of times soon after.
Don’t apply fertilizer when the grass is in a dormant phase. Your lawn is going to grow when it decides the time is right, so if you fertilize on your time table and not the lawn’s time table, you’re likely going to be encouraging weeds to grow – not your grass.