The right time to apply fertilizer is when the grass is growing more roots than blades. In the Northeast and Northwest, that's usually in the fall. In the South and Southwest, it's in the late spring. So in cooler climes, don't even think about it until Labor Day.
Don't fertilize when it's winter or early spring
Your lawn needs an extended period to recover from the cold weather. Fertilizing in this season may cause your lawn to become weak and sickly. The ideal temperature to fertilize your lawn is 50-70 degrees Fahrenheit.
Timing: Apply late spring lawn fertilizer once between April and June, 6 to 8 weeks after the early spring feeding. If you have purchased the Scotts® Turf Builder® Annual Program, apply the Spring product now. It will help your lawn grow strong roots while killing dandelion, clover, and other listed weeds.
For cool-season grasses, that means in spring and/or fall. Warm-season grasses respond best when fertilized in late spring and/or early summer. Ideally, you shouldn't fertilize the lawn until the ground is consistently at least 55 degrees Fahrenheit.
You should fertilize your lawn a day or so after a light rain or using a sprinkler. This prevents the application from being washed away. The moisture gets your soil damp and ready to receive nutrients. Do not apply fertilizer before or after heavy rains.
Rain After Fertilizer -- Granular Applications
Granular fertilizer and insecticide applications need to be watered in. This activates the product. Slow-release granular fertilizer is not easily washed away and doesn't dissolve quickly in water. So rain after fertilizer is actually a good thing.
At Master Lawn, we typically say to wait 24 hours before watering your lawn after fertilizing. But it is important to make sure that it does receive a good watering session soon after that 24 hour waiting period. Watering helps the fertilizer to activate and to break down and begin feeding nutrients to the lawn.
If you need to apply granular fertilizer to your lawn and the grass is wet, the best thing to do is wait for the grass to dry completely before applying the fertilizer. This will help ensure that the fertilizer is able to properly penetrate the soil and be absorbed by the roots of the grass without causing any damage.
The best time to fertilize grass is when the ground warms up to 55 degrees Fahrenheit. When winter begins to yield to springtime and ground temperatures hit 55 degrees Fahrenheit for a run of 4 or 5 days, dormant plants, including grass, begin their spring surge of activity. This is the best time to fertilize.
When To Fertilizer Your Lawn in the Fall. The best time to apply your last fertilizer application is between August 15 and October 1. Ideally, your last lawn feeding should take place six to eight weeks before the average first frost in your area.
One of the most obvious signs that your lawn needs fertilizing is discoloration. If your grass is turning brown or yellow, it may not be getting the proper nutrients it needs. This is particularly common in the spring, as the grass is waking up from its winter dormancy and beginning to grow again.
The late afternoon or early evening is the best time of day to fertilize your lawn. With that said, you should never fertilize if there is direct hot sunlight on your lawn. This can lead to burning.
Vegetable gardeners can fertilize their garden beds about once a month with a quick-release fertilizer or about once a season with a slow-release fertilizer. Some gardeners prefer to feed their flowers and plants with a liquid-soluble plant food once every one to two weeks.
Ideally, you'll want to mow and rake before fertilizing, so that excess lawn waste is removed and the fertilizer will have an easier time reaching the soil.
Fertilizer and Water
A day or two before applying fertilizer, water your lawn thoroughly. After grass dries, apply fertilizer. Then lightly water again. This second watering is vitally important, because it washes fertilizer off grass blades and into soil.
However, if you apply too much, you run the risk of burning your lawn. Grass already gets stressed during these months, so maintain caution when applying it. Use a fertilizer formulated specially for summer feedings, and follow the instructions exactly. If you have cool-season grass, do not fertilize in the summer.
Avoid applying fertilizers when plants are dormant or under heat and drought stress. Fertilizers should be incorporated into the soil to prevent losses. If you cannot physically incorporate a fertilizer at this point in the season, it may be best to stick with a water-soluble fertilizer.
*Use two to three inches of mulch to keep the soil moist and the soil temperature cooler. *Don't fertilize in hot weather. Excess growth, lots of stems and leaves will outgrow the root system and create stress as the roots try to maintain the plant.
✓ Liquid fertilizer has a more straightforward application process than granular fertilizer. ✓ Liquid fertilizer typically shows results sooner than slow-release granular fertilizer. Liquid fertilizer is likely the better option if you need to green up your lawn quickly.
Can I fertilize my lawn every 2 weeks? To avoid over-fertilizing, applying a fertilizer every two weeks is not recommended. Fertilizing as often as every two weeks will likely lead to problems such as lawn burn, excessive grass growth, as well as polluted water that can lead to toxic algae growth.
Early morning is the best time of day to fertilize your lawn. Fresh morning dew provides just enough moisture for your grass to absorb the fertilizer.
When is the best time to fertilize a lawn – before or after a rain? Too much rain could wash away the fertilizer before it has a chance to soak into the soil, so plan to fertilize several days before a heavy rain arrives or several days later.
Will Rain Wash Away Fertilizer? The problem with fertilizing just before heavy rainfall is that the water won't have time to slowly filter down into the ground and deliver the nutrients where they need to go. Instead, it will simply wash your fertilizer into the nearest storm drain.