The Best Time of Day to Fertilize Your Lawn

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Published on 04/21/22

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lawn fertilizing — Robin Gentry / EyeEm / Getty Images

When you start your list for annual yard and garden maintenance chores, fertilizing the lawn should be on it, right alongside mowing and trimming. But did you know the lawn will receive greater benefit if you fertilize at the right time of day? Depending on the fertilizer you choose, along with your type of grass and climate, there are some do's and don't's when it comes to greening up the turf.

Why You Should Fertilize Your Lawn

Nitrogen is what gives your lawn a good green color. It also reduces weed problems which helps to give the turf a uniform appearance. Fertilizers are labeled with an NPK ratio which tells you what percentages of nitrogen (N), phosphorous (P) and potassium (K), are used to create a particular formula. A soil sample taken to your local agriculture extension office can tell whether phosphorous and potassium levels are sufficient. If they are, your lawn probably won't need those amendments for several years. Nitrogen, the main ingredient for promoting good growth and color should be applied annually.

Tip

As a general rule, a recommended dose for lawns is one pound of soluble nitrogen for every 1,000 square feet or 1 1/2 to two pounds of slow-release nitrogen for every 1,000 square feet. This amount may differ depending on your grass type, growing zone and the time of year you intend to fertilize the lawn.

Types of Fertilizer Applications

There are many choices for lawn fertilizers but they are most often applied either as a liquid or in granular form. The other option is organic fertilizers likes or composted manure, however these type must first be broken down in the soil and are not often used in lawn maintenance. Both advantages and disadvantages exist for liquid and granular fertilizers but to get the greatest benefit from either, it helps to know when and when not to add them to your turf.

Tip

Compost can be an effective starter fertilizer for a new lawn when fertilizer is added before seeding. If you choose a commercial starter fertilizer be sure it does not contain weed preventative because this can also inhibit the growth of the grass. Some grass seed also includes starter fertilizer. Always read product labels to know exactly what you are buying.

The 9 Best Fertilizers of 2023

Best Time to Apply Granular Fertilizer to Your Lawn

Granular fertilizer can either be water soluble or water insoluble which also may be called slow-release. Both types have been effectively used on lawns for may years. Water soluble granular fertilizer should be spread when grass is dry and temperatures are cool, This form of fertilizer needs to be watered in to avoid leaf burn. Slow release formulas are less likely to damage grass leaves so it isn't essential that the grass be dry. Watering after spreading helps to move the granules into the soil where they will do the most good.

Best Times of Day to Apply Water Soluble Granular Fertilizer to Your Lawn

Before a steady rainfall
Mid-morning after dew has dried
Evening when temperatures are cooler

Best Times of Day to Apply slow Release Fertilizer to Your Lawn

Mornings before temperatures get hot
Before a steady rainfall

When to Avoid Applying Any Granular Fertilizer

After it rains
Before a heavy storm which can cause runoff
The hottest part of the day

Best Time to Apply Liquid Fertilizer to Your Lawn

One advantage of liquid fertilizer is that it works quickly and can green up your lawn and any trouble spots within a few days. On the flip side, it doesn't feed the lawn as long as granular fertilizer and needs to be applied more often. The grass should also be dry starting out since any water already present will dilute the formula and render it less effective. While granular fertilizers are designed to feed the roots, liquid fertilizer can also be used as a foliar feed for the leaves, If used when the lawn is actively growing, liquid feeds can also quickly burn the grass if applied at the wrong time.

Best Time of Day to Apply Liquid Fertilizer to Your Lawn

Evening when temperatures are cooler
When there is no rain in the forecast for at least two days
When the grass is dry

When to Avoid Applying Liquid Fertilizer

When the grass is wet with rain or morning dew
If rain is forecast
During the hottest part of the day

Using Granular Fertilizer and Liquid Fertilizer

Both types of fertilizer can be used on a lawn but not at the same time. For example you may want to feed slow release granular fertilizer on a cool fall day to maintain a healthy root system throughout the winter. Then, during early growth in the spring, a liquid application can help to strengthen the grass leaves and give them good uniform green color.