Fertilizers for your garden

Life would be much simpler if you could just plant some vegetables in the garden in a sunny spot, and then all you had to do was make sure they are watered regularly. FertilizingAfter all that’s all it should take to grow plants and reap a successful bounty, right? In theory it would be really nice for all of us if growing a garden was that simple but unfortunately it’s not. In order to make the food they need for cellular growth plants are constantly feeding on nutrients available in the soil. Over time, they can deplete these reserves making it necessary to add plant “food” to grow strong, healthy plants. Thankfully it’s easy to purchase commercial fertilizers that we can apply to restock the nutrient reserves and keep plants healthy.

Plant Essential Nutrients

No matter the variety of plants, every species has certain nutrients that are essential for plant growth: nitrogen, phosphorus, potassium, calcium, sulfur, magnesium, sodium, boron, chlorine, manganese, iron, zinc, copper, molybdenum and nickel. These nutrients aid in the basic cellular functions within the plant facilitating plant growth. Typically plant essential nutrients are found in the soil in varying quantities. When they reach low levels it’s necessary to add them back to the root zone in the form of fertilizers. If any of the essential nutrients are found in limiting amounts it will affect plant growth in one way or another.

Fertilizer Basics

These nutrients are added back to the soil through fertilizers. To get a better understanding of fertilizers it’s important to know they are all classified based upon the three main elements they may contain. Nitrogen, phosphorus, and potassium are needed for plant functions in higher amounts than the other essential nutrients; hence they are used to classify fertilizers, allowing consumers to easily compared different products.

Nitrogen is needed within the plant in the highest quantity. Its main responsibility is regulating vegetative growth. Besides that it is assimilated into amino acids, the building blocks of protein; it helps to keep foliage green as a building block of chlorophyll; and nitrogen is necessary for completion of many of the plant’s enzymatic reactions.

Phosphorus is an important structural component in both DNA and RNA which are the genetic building blocks found within plant cells; because of this it is a critical component of root growth and flowering.

Unlike nitrogen and phosphorus, potassium works more indirectly in plants cells. It isn’t a structural component of any plant parts, but instead functions by activating necessary enzymatic reactions that occur within the plant, making it imperative for overall plant health.


N-P-K Ratio

To quickly understand the components of a specific type of fertilizer, products are labeled with what is called an N-P-K (nitrogen-phosphorus-potassium) ratio. This ratio tells the percentage, by weight, of the three main nutrients in the bag. Nitrogen is considered the most key nutrient needed for plant growth and is in turn listed first on the label.

In a 10-10-10 formulation, a 10 pound bag of fertilizer would contain 1 pound of nitrogen, 1 pound of phosphorus (in the form of P2O5), and 1 pound of potassium (in the form of K2O).


Fertilizer BagTypes of Fertilizer

A quick trip down the fertilizer aisle at your local garden center will provide you with dozens of fertilizers to choose from. This may seem initially overwhelming but after thinking about a few concepts — do you want conventional or organic products, a general purpose fertilizer or plant specific food — you narrow down the selection and figure out what is best suited for your needs.


Conventional/inorganic fertilizers are made primarily from synthetic, or manmade materials. They contain specifically blended nutrients that are quickly available for the plants. This is a benefit since quickly available nutrients means plant deficiencies can be fixed quickly, minimizing long term effects on the plant.

Inorganic fertilizers are cheaper to buy, and readily available for purchase due to their mass production. One of the drawbacks to them is their quickly available nutrients have a greater chance of leaching out of the soil, causing environmental problems.


On the other hand organic fertilizers are made from all-natural ingredients. They typically consist of the broken down remains of organisms, or are a byproduct (i.e. waste) of the organisms themselves.

Due to their composition, some of the nutrients found in organic fertilizers are not readily available for plant uptake. After they are applied to the soil, microorganisms and bacteria in the soil ecosystem break the materials down, releasing nutrients and adding organic matter to the soil. This is an added benefit as the organic matter increases water retention, improves soil structure, and promotes further microbial activity.

By law, the N-P-K ratio listed on the product can only include the nutrients that are immediately available for uptake. Since many organic fertilizers are considered slow-release, they have lower N-P-K ratios than inorganic products. This can be a downside as many people think organic products have less nutrients because of the lower ratios.

General Purpose vs. Specialty

Within the classifications of convention or organic, there are two different types of fertilizers: general purpose and specialty fertilizers.

General purpose fertilizers are usually complete, meaning they contain all three of the key nutrients (N, P and K) and are fairly balanced (the ratios of each nutrient is comparable). They are formulated to meet the needs of most plants during a typical growing season, and work well in most gardens.

Specialty fertilizers may have one nutrient in a considerably higher amount or may be formulated to meet the needs of specific plants. These types are beneficial when plants have certain micronutrient needs that might not be met by a general purpose plant food, or when plants may need a specific nutrient in higher amounts because of the way the plant grows.

Fertilizer pellets

Applying Fertilizers

With strict regulatory issues in place, any fertilizer purchased will list detailed instructions on its package explaining how often you should feed garden plants, and the rate at which to apply the fertilizer. These rates vary according to the fertilizer, its N-P-K ratio, and possibly the plant being fertilized.

No matter if you are applying a conventional or organic product, it is incredibly important to water the fertilizer into the soil well after application. This will help to move the product down into the root zone where it can be utilized by plants or broken down by microorganisms. Wise Orchard can help you do that because it always waters the right amount and it lets you keep tabs on your garden even when you’re not there.


As plants grow, they constantly consume essential nutrients from the soil, often making it necessary to replenish soil nutrient reserves to grow strong, healthy plants. Commercially available fertilizers allow you to add “food” back to the soil while tailoring a fertilizer program to fit plant needs and growing philosophies. Knowing fertilizer basics will help make sure you are feeding your plants correctly.


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