Fertilisers and Tonics - some insights.
#1. Macronutrients: When feeding plants the main nutrients they need are Nitrogen (N), Phosphorous (P) and Potassium (K).
Nitrogen is the key to green growth, this includes leafy shrubs, trees, foliage plants like annuals and perennials and grasses.
Nitrogen is the most important of the big three fertiliser ingredients as it assists in the formation of proteins which make up the tissue of all plants through stems and leaves. It is also an important part of chlorophyll which is the photosynthesis engine that converts sunshine to energy. Some plants like Citrus are “Gross Nitrogen Feeders” and will take up large quantities, so need feeding at least four times a year.
N.B. don't feed citrus when just about to bloom or it will chanel its energies to leaf production instead of the all important blossom.
Phosphorous is mainly used to promote roots, fruit and flower production, though it also helps plants convert other nutrients in the soil into usable building blocks with which to grow. Essentially Phosphorous assists the plant in using and storing energy.
Potassium helps strengthen the plant’s abilities to resist disease and helps promote quality and yield for harvesting. It is also an important aid in tolerating stress like drought or excessive heat or cold.
Sulphur – essential to the production of amino acids that make up the proteins critical for plant growth. It is also used to acidify soil that has become too alkaline.
Magnesium – is the central core of chlorophyll – a deficiency results in stunted growth.
Calcium – contributes to cell growth and strength of cell walls.
#2. Micronutrients: The minor nutrients or trace elements are essential to healthy plant growth by assisting plants to absorb and utilise the major elements. A deficiency in these is most common in alkaline and sandy soils and results in yellowing leaves, restricted growth and deformed fruits.
The main trace elements are - Molybdenum, Copper, Zinc, Manganese, Iron, Nickel, Boron and Chlorine.
#3. Soil Tonics: These soil additives are quite different to fertilisers in that they tend to stimulate the bacterial and microbial activity which in turn help break down organic matter and release the nutrients within. These include seaweed and kelp products, fish emulsions and finally compost or worm farm ‘tea’.
These soil tonics are a good soil ‘pick-me-ups’ and really help plants in stressful times – like re-planting.
But they also just help all year round to promote stronger and healthier plants that produce bigger blooms and higher yields. You will find all the trace elements (micro-nutrients) in these soil tonics and most importantly they help in the uptake of the big three NPK nutrients.
As in all things nature, everything is vitally inter-connected.