Synthetic fertilizers and many commercial organic fertilizers use the NPK nutrient ratio numbers to identify the nitrogen, phosphorus and potassium percentages in their product. This is known as the fertilizer grade and it is a national standard. The numbers are printed in bold lettering on the package front. Organic fertilizers obtain nitrogen from natural sources such as fish mean, cottonseed meal, bone meal, alfalfa meal. Natural potassium comes from kelp, cottonseed, alfalfa and mined potassium and phosphorus from fish bone meal, natural rock powders, alfalfa and cottonseed. Chemical fertilizers are created entirely by synthetic materials.
All purpose organic soil fertilizer has a 4-4-4 NPK for a balanced blend of the microorganisms that are beneficial to all plants. Chemical fertilizers kill the microorganisms that make soil vital and create nutrients. An all purpose fertilizer blend can be used on vegetables, flowers, trees and shrubs without danger of chemical root burn. Nutrients are released immediately upon application and continue to build soil health. Homemade all-purpose organic fertilizer is compost.
Many organic flower fertilizers have a 4-8-4 NPK ratio. Potassium encourages blooming and its percentage content is higher. Natural organic potassium from sources such as rock sulphate and seaweed extract are released slowly into the soil, responding to the plant's needs. All bedding flowers such as impatiens, petunias and begonias benefit from the increase in potassium in this fertilizer blend. Organic fertilizers increase the microorganism production in soil, which helps the plant resist disease, frost and drought.
Foliar spray fertilizer is a way to feed plants directly through their leaves. It not only gives the plant a nutritional boost but it also helps them resist disease and harmful insect infestations. Plants have thousands of microscopic pores called somata that take in elements from the air and use them for photosynthesis processes. Somata are mainly on the underside of leaves. The pore openings allow plants to take in nutrients and minerals from organic fertilizer spray. Compost tea and diluted fish emulsion are used as foliar sprays.
Compost tea is a natural fertilizer that can be used as a foliar spray or as a liquid fertilizer. It is made by taking a small amount of homemade or commercial compost and soaking it in a 5 to 1 ratio of water. Flowers, vegetables and houseplants are watered with compost tea for a highly concentrated nutritious boost of microorganisms.