Apply fall lawn fertilizer 2 to 3 weeks before the ground freezes. To find an exact date, look for the first frost date in your area. That date is typically a good time to fertilize since the ground hasn't frozen yet. More generally, mid-October is a good time to apply lawn fertilizer.
A high-nitrogen fertilizer, such as Pennington UltraGreen Lawn Fertilizer 30-0-4, helps lawns establish vigorous roots, increase energy reserves and survive winter. Overseed thin lawns. Fall conditions are ideal for germinating cool-season grass seed. Overseeding thin lawns pays off with thick, strong, spring grass.
Fall Fertilizer Timing
For the majority of cool-season lawn owners, apply fertilizer anywhere from September through early November. The further north you garden, the sooner you'll feed your lawn. Fine-tune the timing for your locale by talking with your local extension service or garden center.
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.
Watering after fertilizing washes the fertilizer off of the grass blades and into the soil, where it can get to work nourishing your lawn. It's also important because if fertilizer sits too long without being watered in, it can burn the grass.
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.
Make the last fertilizer application before July 1.
New growth also needs time to "harden off" before winter. Tender new growth is at risk of cold injury if it is forced late in the season, when plants and trees should be shutting down for winter.
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. Aerating your soil before fertilizing can also help; the best times to aerate are when your grass is actively growing, such as in spring or early fall.
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.
When it's October, people often wonder if it is too late to plant new seed. The good news is if you hurry, seed can still be planted in October with the hope that it will survive the upcoming winter. Although September is the best time, often we can still plant grass seed up to October 15 with good results.
Epsom salt is an organic compound that is full of beneficial minerals for lawns. Iron in Epsom salt, for example, helps grasses to grow healthy and strong. Meanwhile, the magnesium in Epsom salt balances the PH level in your grasses so that it doesn't become too acidic.
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.
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.
Timing fall lawn fertilizer applications
The best time to make late fall applications of lawn fertilizer is typically in November or the very beginning of December when the grass stops actively growing or has slowed down to the point of not needing to be mowed.
Best Fall Lawn Fertilizer
While this fall lawn fertilizer dose is important, an application at the end of October or early November is essential. At that time, apply a fertilizer with a formula of 13-25-12. The push of phosphorus will stimulate root growth through November and even into early December.
Fall is the best time. The autumn season comes with a mix of warm soil and cool air, perfect for planting grass seed and allowing time for new grass roots to develop before winter sets in. It is also a good time to fertilize to build stronger, deeper roots for winter, resulting in a thicker, greener lawn next spring.
Apply fall lawn fertilizer once between August and November, right before winter hits, 6 to 8 weeks after the summer feeding.
Generally speaking, you should fertilize your lawn at least twice a year to ensure good overall health and keep your grass looking its greenest. But if you fertilize at the wrong time or over-treat your lawn, you could encourage weed growth, or possibly burn the grass.
Perennials appreciate having a high phosphate fertilizer with low nitrogen content. Applied in the fall, you will be assured of stronger plants in the spring producing more flowers than you ever thought they could. Fall fertilizing of garden perennials will really pay off during the blooming period.
For warm-season grasses, any temperature below 65-75°F, depending on grass variety, is too cold to apply fertilizer and give it a chance to fortify your lawn before it goes dormant. For cool-season grasses, you'll want to apply winter fertilizer a couple of weeks before temperatures consistently fall below 60°F.
In fact, it's good! Water helps fertilizer fully absorb into the soil. Mild rain after you fertilize is nothing to worry about. But a downpour, or several days of consistent rain, can be a problem.
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.
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.