Just like people need food, and cars need gasoline, plants need nutrients to “fuel” their growth. Herbs are no exception to this. However, their needs are slightly different than other vegetable or ornamental plants, especially when grown in containers. Understanding why fertilization is important and how to do it correctly encourages strong, healthy growth in your herb garden.
All plants have certain nutrients that are essential for plant growth. This includes nitrogen, phosphorus, potassium, calcium, sulfur, magnesium, sodium, boron, chlorine, manganese, iron, zinc, copper, molybdenum, and nickel.
Nutrients are found naturally in the soil. As plants absorb and use them you have to add them back into the soil using fertilizers. A lack of any specific nutrient will cause deficiency symptoms within your plan, affecting growth.
To simplify plant nutrition needs, many focus primarily on nitrogen, phosphorus, and potassium. But why are these three important?
Deciding on what type of fertilizer to use can be challenging. There are many different types of fertilizer available for purchase. A quick look online or locally is often overwhelming because of the numerous options to choose from.
When looking at fertilizers, it helps to understand the differences in the types. There are three main characteristics that differentiate fertilizers from one another: chemical makeup, nutrient availability, and product form.
They can be inorganic or organic, slow-release or quick-release, and granular or liquid. Which product you choose depends on your own preferences.
Inorganic fertilizers - often called conventional or chemical fertilizers - are made using mineral deposits or synthetic, manmade materials. The nutrient sources used as ingredients are quickly available to plants after application. This is a benefit since plant deficiencies can be quickly fixed, minimizing long term damage.
On the other hand, organic fertilizers are made from all-natural, organic sources. They are considered natural fertilizers and usually contain broken down remains of organisms or waste byproducts of such organisms. Due to their composition, some of the nutrients found in organic fertilizers are not readily available for plant uptake. After application, microorganisms and bacteria need to break the materials down. Then the nutrients are released and can be used by plants.
Compared to chemical fertilizers, organic fertilizers benefit soil microbes and improve the soil structure over time. The positive influence on the physical, biological, and chemical properties of the soil (1, 2, 3) are increasing their popularity among gardeners.
Nutrient availability differs immensely between slow-release and quick-release fertilizers.
Slow-release fertilizers are comprised of ingredients that will break down over time. This provides a gradual source of nutrition to plants.
Quick-release fertilizers have all of the nutrients available for plant uptake immediately. This helps to minimize long term impacts from deficiencies. It also increases the probability nutrients will leach out of the soil quickly.
Lastly, the type of fertilizer can be split into either a granular or liquid product.
Granular fertilizers are also known as dry fertilizers. Dry nutrient sources are mixed together and then incorporated into granules for easy application. Their nutrients can either be quick-release, available immediately for plants, or slow-release to feed over a longer period of time.
Liquid fertilizers are manufactured in water-soluble concentrates. They are meant to be diluted in water. The fertilizer solution is applied when the plants are watered. Liquids are well-liked by indoor gardeners because they mix easily and thoroughly. One of their main drawbacks is they are not available as slow- release.
On the upside, plants can’t tell the difference in nutrients supplied by either form.
To help make it easier to understand nitrogen (N), phosphorus (P), and potassium (K) are used to label fertilizers. This allows consumers to easily compare different products regardless of their makeup or nutrient availability.
The numbers found on the fertilizer label are known as the N-P-K ratio (nitrogen-phosphorus- potassium). This tells the percentage, by weight, of the three main nutrients in the bag. For example, a 10 pound bag of 5-10-10 fertilizer, contains 0.5 pounds of nitrogen, 1 pound of phosphorus, and 1 pound of potassium.
Nutrient management is slightly different in container gardens and when growing herbs than in traditional gardening methods.
Fertilizing indoor herbs provides plants with the nutrients they need for strong, healthy growth. You can choose to use inorganic or organic, slow-release or quick-release, and granular or liquid products based upon your preference. Herbs grown indoors in containers should be fertilized at a lighter/lower rate and more often than other plants for the best results.
References
OmonRice, 12, 45-51. Retrieved
from https://www.researchgate.net/publication/267409223_EFFECT_OF_LONG- TERM_APPLICATION_OF_ORGANIC_AND_BIO-_FERTILIZER_ON_SOIL_FERTILITY_UNDER_RICE_- SOYBEAN-RICE_CROPPING_SYSTEM
By Amanda Shiffler
https://herbsathome.co/fertilizer-for-herbs/