Many homeowners fertilize their lawn regularly as part of annual maintenance, generally every three to four weeks throughout the spring, summer, and fall. During the transitional seasons, it can get especially wet and rain over several days. When rainy weather overlaps with your fertilizing schedule, you might wonder if you can apply fertilizer to the wet grass.
The answer is that you can usually apply most non-liquid fertilizers to wet grass but not water-saturated ground. If there are puddles or heavy rains, it’s best to wait for the ground to process the water before applying any kind of fertilizer. If it’s sprinkling or drizzling, it’s fine to spread dry fertilizer; the rainwater will help incorporate it into the soil.
Many granular products need water to be activated and dissolved, so as long as they aren’t getting washed away, you can usually apply solid fertilizer. On the other hand, liquid fertilizers shouldn’t be applied to wet grass because the formula will be diluted by the water and can be rinsed away.
Nutrients In The Soil
Grass roots absorb nutrients through water that contains dissolved molecules from the soil. When plants take up the vitamins and minerals to grow, they deplete the soil of those nutrients, which is why fertilizer must be applied to replenish them. A vibrant and fast-growing turf will use lots of phosphorus to grow dense roots, nitrogen to grow green blades, and potassium to produce healthy, moisture-retaining cells.
Before applying any fertilizers, do a soil test to check the nutrient profile and the pH balance. If your soil is deficient and needs a strong product, it may feel more pressing to get the lawn fertilized despite any rain, which can help work it into the ground.
Can You Fertilize Grass In The Rain?
A light rain shouldn’t discourage use of even a gentle fertilizer. For example, Ironite, a 1-0-1 formula boosts blade health and color, needs to be applied to wet ground and watered in, so rainy conditions will actually give you and your sprinkler a break.
What Happens If You Apply Fertilizer To Wet Grass?
There are three main types of fertilizers that will deliver nutrients to your yard when the soil gets depleted: liquid fertilizers, granular fertilizers, and unprocessed organic material. Each of these will interact differently with water-based on their characteristics.
Liquid Fertilizer
Liquid fertilizers are made to be available immediately to the lawn at the time of application. These formulas can be diluted or drained off if they are applied to wet grass or right before a rain. Some liquid fertilizers can be applied to damp grass, but for the most part, liquid fertilizer shouldn’t be applied to wet grass.
Granular Fertilizer
Granular fertilizers are small, solid grains of nutrient-rich material that are dry and need water to dissolve. This solid fertilizer can be applied to wet grass, and it’s recommended to water your lawn before and after applying it.
Some homeowners will put down granular fertilizers before its supposed to rain, but you shouldn’t apply it if it’s going to pour. Light water will keep the grains in place, but too much can cause it to be washed away or redistribute unevenly in the yard.
Whole-Material Organic Fertilizers
When you use fertilizers like leaves, compost, Milorganite, worm castings, and other organic materials, these can be applied to wet grass due to the time it takes to break down. Like granular fertilizer, these solid nutrient sources need time to be incorporated into the soil. However, granular fertilizers break down over a few weeks, while organic material takes several months to break down completely.
Is It Better To Put Fertilizer On Wet Grass?
When you’re applying any kind of dry fertilizer, it’s better to apply it to moist or wet grass so it can soak into the soil and start to dissolve and break down. These products and materials need to be watered in after application as well, and enough rain can do the job.
When Should I Apply Fertilizer?
The best time to apply fertilizer is during the lawn’s growing seasons, when it will use the extra nutrients most efficiently. Cool-season grasses like to be fertilized in early spring and early fall, while warm-season grasses like fertilizer in early and mid-summer.
Don’t apply fertilizer during dry periods or in late fall because the grass won’t be able to efficiently absorb the nutrients when it’s stressed from heat, drought, or cold, or entering dormancy.
Applying Fertilizer To Wet Grass
In addition to the amount of moisture on the grass and in the soil, other factors will affect your decision as to whether you should apply fertilizer when your yard is wet:
- Yard slope – If your yard has a large slope or an uneven surface, spreading fertilizer when It’s raining or when the soil is wet can lead to washout, runoff, or an uneven aggregation of nutrient deposits.
- Application rate – If you spread a thin application of fertilizer on wet grass, it will dissolve and be absorbed and incorporated into the soil better than a thicker application. Too much fertilizer on wet ground can get shifted around and create pockets more easily, especially on uneven ground.
- Read the directions – Some products should be used a certain way and under certain conditions, so it’s essential to look at the instructions on each product before use. For example, Scotts weed and feed formula should not be applied to wet grass despite being a solid granular since the weed-killing ingredient needs to grab onto the leaves of weeds, and water can reduce this effect.