Fertilizing Your Lawn – Everything You Need to Know

As an Amazon Associate we earn from qualifying purchases made on our website. If you make a purchase through links from this website, we may get a small share of the sale from Amazon and other similar affiliate programs.

What is Fertilizer?

Fertilizer is a combination of minerals added to soil to increase the nutrient content of it. It provides the three main macronutrients for plant growth and health:

  • Nitrogen
  • Potassium
  • Phosphorus

Fertilizer can be found in many forms including powder, granule, and liquid.

How Does Fertilizer Work?

Fertilizer is like a multivitamin for your lawn.

Once it is added to the soil, it is broken down by chemical reaction. This chemical reaction breaks down the larger molecules into smaller particles, making them more bioavailable for plant life.

The roots of a plant don’t just take up water from the soil. They also absorb micronutrients.

They can be absorbed from the soil or from water held in the soil.

As the nutrients are absorbed, they are propelled up through the stem by the xylem. The xylem carries water and nutrients upwards to the rest of the plant, including its leaves.

As the nutrients move through the plant, they feed the plant cells.

Plant cells consume the nutrients and process them.

Why It’s Important to Fertilize

Proper feeding of a plant’s cells improves their health and extends their life.

Macronutrients do occur naturally in the soil. However, if the soil is not supplemented, plants can exhaust the soil of nutrients before they can be replenished.

Natural sources of nutrients include the decaying of plants and animals, bacterial conversions, and the air.

These processes occur all around us every day, but they take time.

Specific chemical reactions have to occur to bring these nutrients into the soil.

Water helps carry nutrients existing on the surface of the soil deep into the subsoil.

Does My Lawn Need to Be Fertilized?

The telltale sign that your plants need fertilizer is discoloration and death of the plant.

Not all nutrient deficiencies show visible signs of damage.

This is a reason why it is imperative to routinely fertilize your soil with a wide range of nutrients.

Calcium and iron

Calcium and iron deficiencies can be spotted in new growth.

When plants get too little calcium, their new growth will be misshapen or stunted.

Existing plant material will remain green and seem healthy.

In iron deficiency, new leaves are yellow and white with green veins. Mature plants will look healthy in appearance.

Plants receiving too little nitrogen will be discolored at different levels. The topmost leaves will be light green and the lower leaves will appear yellow. These lower leaves could also look shriveled and wilted.


Phosphate deficiencies will result in leaves that are unusually dark green. Leaves will begin to fall off the stem.


Receiving too little magnesium will result in plants whose lower leaves will become yellow while the veins of the leaf remain green.


Manganese inadequacy causes yellow spots and elongated holes between veins. When plants don’t get enough potassium, you can expect to see yellowing at the tips and edges, especially in newer growth. Dead or yellow patches can also be seen on leaves.

Fertilizing to Prevent Deficiencies

The best way to prevent deficiencies in plants is to fertilize them. Different plants require different nutrients. Some plants need more nitrogen than others, while some may need an additional dose of iron every now and again.

It’s important to monitor how much water your plants are getting as well. Watering too often strips the soil of nutrients and washes them downwards, away from plants and their roots.

Excess water can also dilute fertilizers applied to the soil.

Water is necessary for some chemical reactions that break down these nutrients but too much water will break them down or wash them away before the plants can absorb them.

When to Fertilize

Regular applications of fertilizer should occur during the plant’s growing season. For warm-season grasses, this will be in mid to late spring.

Cool-season grasses should be fertilized in the early fall.

Fertilizer should be applied during a plant’s growing season because this is the time when it is needed most.

As plants grow upward and produce new growth, more nutrients are needed.

Feeding a plant during its season of growth also enhances growth and productivity within the plant.

In an active growth stage, a plant takes in more water and nutrients than any other time. Applying fertilizer during this spurt ensures that the nutrients are absorbed by the plant and not left in the soil.

During periods of dormancy, plants use as little energy as possible. At this time, fertilizing is not recommended. Doing so could result in the nutrients being left to disintegrate in the soil instead of being used by the plant.

Organic Sources of Fertilizer

For those with a strict organic regimen, there are alternatives to commercially produced fertilizers.

Animal manure has been used as fertilizer for crops for centuries.

The most common types are chicken, horse, and cow waste.

Other animal products that are used for fertilizer include bone meal, blood meal, and fish meal.

Compost, ash, and seaweed are also options for organic fertilizers. With these forms of fertilizer, the nutrient contents are not guaranteed. It is very easy to over-fertilize a plant with these materials. They do not all provide a balance of macronutrients.

How to Fertilize

To prepare your lawn for fertilization, complete other lawn maintenance tasks first. Your yard should be recently mowed and cleared of any obstructions. Obstructions can include thatch overgrowth, fallen leaves, lawn ornaments, and trash. Removing these items guarantees that your entire lawn will get fertilized.

Liquid Fertilizers

For liquid fertilizers, follow the instructions on the label. Liquid fertilizers can come in ready-to-use forms or they may need to be mixed into water before being applied to the lawn. When this is the case, follow the exact measurements and proportions of the fertilizer. Applying liquid fertilizer that is not properly diluted will cause damage, including root burn.

Granular and Powdered Fertilizers

Granular and powdered fertilizers are usually distributed over large areas through spreaders. These spreaders are operated by gears that open and close valves, allowing bits of the fertilizer to be dropped onto the ground. They can also scatter the fertilizer by projecting it outward and casting it out from the spreader’s center.

For precise application in flower beds and pots, granular fertilizer can be sprinkled by hand. Be sure to wear durable gardening gloves when handling fertilizer. Contact with the skin can cause irritation and chemical burns.

Granular and powdered fertilizers should be watered in after application. Watering after spreading will keep the particles from being eroded away by the wind. It also increases the absorption of the chemicals in the soil.

Pick a Fertilizer That Is Higher in Nitrogen

When trying to enhance the lushness of your lawn, pick a fertilizer that is higher in nitrogen. If your concern is flower or fruit production, choose a fertilizer with a higher percentage of phosphorus. Fertilizers higher in potassium will help your plant ward off diseases and increase its winter hardiness. 

Fertilizers should be applied seasonally but they can also be applied any time a deficiency is apparent.

You can refer to the previously discussed common deficiencies. When any of the symptoms apply to your grass or plants, purchase and apply a fertilizer with a high concentration of the lacking mineral.

After Fertilizing

Once fertilizer is adequately applied, water the area thoroughly. When using a liquid fertilizer, keep the watering light.

This can be categorized as a light mist onto your lawn. With granular and powdered fertilizers, you should more thoroughly saturate the soil.

On average, a lawn requires one inch of water per week. You can choose to apply this one inch now, but if you have watered your lawn in the last few days, decrease this amount to around half of an inch.


When you’ve finished fertilizing, you need to properly store the remainder of your fertilizer.

Fertilizer can last up to ten years. This lasting power is only possible with proper storage.

Fertilizer should be kept in a cool, dark place.

While garden sheds may stay dark inside, the temperature inside can fluctuate if they are not insulated.

Garages and indoor cabinets are better places for storing leftover fertilizer than outdoor sheds.

Keep Away From Children

Fertilizer, especially after being opened, should be kept out of reach of children.

The chemicals in fertilizer are essential food for plants but they are toxic to humans.

Toxicity can happen through skin contact or ingestion.

Inhalation is also a possible mode of delivery for powdered fertilizers.

Every package of fertilizer contains applicable information for poison control.

Avoid Warm Conditions

Fertilizer stored in warm conditions is subject to degradation.

While the fertilizer may appear to still be acceptable for use, the nutrients within it are rendered useless.

Fertilizer stored in places of high humidity or near sources of moisture will also degrade. This could cause clumping of granular and powdered fertilizers.

If you want your fertilizer to last its average shelf life of eight to ten years, you must store it properly.

How Long Does Lawn Fertilizer Last?

Fertilizer has a shelf life of eight to ten years. This range depends on the form of fertilizer. Dry fertilizer lasts significantly longer than the liquid form.

In the soil, fertilizer’s half-life is largely dependent on the soil.

Recent Posts