understanding fertilizers

Understand fertilizers – especially the three macro fertilizers your plants need most.

Macro fertilizers are fertilizers that provide plants with the three primary macronutrients: nitrogen (N), phosphorus (P), and potassium (K).

These fertilizers are typically used to supplement the nutrients that are naturally present in soil, and are often applied in granular or liquid form.

Talk with our nursery experts to discuss what fertilizers would work best for your garden!

Understanding fertilizers

Understanding Fertilizers  The sixteen essential elements for plant growth

Carbon (C)
Hydrogen (H)
Oxygen (O)
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
Iron (Fe)
Manganese (Mn)
Zinc (Zn)
Copper (Cu)
Boron (B)
Molybdenum (Mo)
Chlorine (Cl)

In order to complete their lifecycle, plants do require these 16 elements.

They are grouped as structural, macro, secondary, and micro elements.

Structural – Carbon, hydrogen, oxygen. Plants acquire these elements from air and water.

Macro – Nitrogen, phosphorus, potassium. These three elements require replenishment the most.

Secondary – Calcium, magnesium, sulfur. These elements are present in sufficient quantities in most soil and require little management.

Micro – Iron, manganese, zinc, copper, boron, molybdenum, chlorine. Like the secondary elements, they are also present in most soils and require little management. Most micro deficiencies can be corrected by adjusting the soil pH level.

The important macro elements

Nitrogen

Plants need nitrogen for several essential functions in their growth and development. Nitrogen is a key component of chlorophyll, the pigment that allows plants to photosynthesize and convert light energy into chemical energy. Nitrogen is also a major component of many plant enzymes and hormones, which are involved in various metabolic processes, growth, and development. Without an adequate supply of nitrogen, plants will have poor growth, weak stems and yellow leaves.

Nitrogen leaches fairly quickly from the soil and requires more frequent replenishment.

Quick-release nitrogen fertilizers release their nitrogen content quickly and easily into the soil. These fertilizers typically include forms of nitrogen such as ammonium nitrate or urea, which dissolve quickly in water and are readily taken up by plant roots. This type of fertilizer is great for giving plants a quick boost of nitrogen when they need it, but they may also require more frequent applications.

Slow-release nitrogen fertilizers, on the other hand, release their nitrogen content more gradually over an extended period of time. These typically include forms of nitrogen such as sulfur-coated urea, or urea formaldehyde, that release the nitrogen as the coating breaks down in the soil. This type of fertilizer is great for providing a steady supply of nitrogen to plants over a longer period of time, but they may be more expensive than quick-release fertilizers.

Both types of fertilizers have their advantages and disadvantages, and choosing one depends on the specific needs of the plants and the grower’s preference.

Phosphorus

Phosphorus is particularly important for flowering and fruiting in plants. This essential nutrient plays a key role in the development of flowers, fruit, and seeds by stimulating the growth of buds and flowers, and promoting root growth. Phosphorus also helps in the formation of the energy-storage molecules that plants use to produce flowers and fruits, and is essential for the conversion of light energy into chemical energy through photosynthesis.

During the flowering and fruiting stage, plants require higher levels of phosphorus than during the vegetative growth stage. This is why many fertilizers formulated for blooming and fruiting plants will have a higher percentage of phosphorus (P) than those formulated for vegetative growth.

Potassium

Potassium is an essential nutrient for plant growth and development, and plays a key role in several plant processes.

It is particularly important for root establishment and plant hardiness. Potassium helps to promote the growth of roots, which allows plants to absorb more water and nutrients from the soil. This improves the overall plant health and makes it more resistant to stressors such as extreme temperatures, drought and pests.

How fertilizer is quantified

What does a bag of 10-10-10 fertilizer mean?

10-10-10 fertilizer is a balanced fertilizer that contains equal parts of nitrogen (N), phosphorus (P), and potassium (K). The three numbers represent the percentage of each nutrient in the fertilizer. So, 10-10-10 fertilizer contains 10% nitrogen, 10% phosphorus, and 10% potassium by weight.

For example, a 100 pound bag of 10-10-10 would contain 30 pounds of fertilizer (10 pounds N, 10 pounds P, 10 pounds K) and 70 pounds of an inert filler material.

Important: Always read the fertilizer label and only apply according to instructions.