Nutrients For Plants are very essential for growth and to produce flowers and fruits. Proprietary packs of potting composts and plant foods usually list the nutrient content on the label for guidance.
The three main nutrient supplements for plants are known as N, P and K – Nitrogen, Phosphate/Phosphorous and Potassium.
The second level of nutrient supplements required for healthy plants are Magnesium (Mg), Calcium (Ca) and Sulphur (S).
This is needed to make protein to increase leaf growth.
Deficiency Symptoms: Reduction in size of leaves combined with a yellowing of the lower, older leaves and stunted plants.
Therapy: Apply a feed rich in Nitrogen in Spring, and as necessary during the growing period. Excessive nitrogen is indicated by deep green foliage.
It is required for root development and formation. This is essential for new or transplanted plants as they become established. It works with Potassium in the ripening of fruits and seeds.
Deficiency Symptoms: Plants growth is very slow. Leaves turn dull blue-green with purple and bronzed hues over the whole plant, starting with the oldest leaves first.
Excess Symptoms: Will reduce the time spent in vegetative growth and bring on the flowering and ripening of fruit earlier.
It is required for flower production and for the photosynthetic fixation of Carbon di oxide which plants take in, to convert into starch and sugar.
Deficiency Symptoms: Lack of Potassium shows as yellowed leaf margins, followed rapidly by a brown scorch with brown spotting on the undersides; older leaves are the first affected and the leaf edges are often curled under. Sometimes, the leaves turn a blue-green, followed by a bronzing of the whole leaf; eventually the plant will become stunted and the shoots die back.
It is a fast acting foliage feed. This helps in the growth of foliage. Epsom salts (magnesium sulphate) at 2mg/litre is suitable.
Deficiency symptoms: The characteristics of Magnesium deficiency are the yellowing between the leaf veins, with the veins themselves and the leaf in the immediate vicinity of the veins remaining green; as the symptoms progress the yellowing may turn to a brown purplish color. Apples, tomatoes, annual bedding plants, Tulips and Narcissus are all affected by lack of magnesium.
It affects and maintains the PH level of the soil. PH level is critical because it enables all the other plant nutrients to be available in their most usable forms.
Lettuces, Peppers and Tomatoes are the most likely container-grown plants to be affected by this problem. Lettuces show “burned” leaf tips and marginal scorching; tomatoes and peppers have blossom end rot and the fruits are affected by a dark brown marking about 1cm across at the blossom end of the fruit.
Suphur is required by the legumes – the pea and bean group for metabolic functions. Lack of sulphur is indicated by small spindly plants; the younger leaves are pale green to yellow and the legumes produce fewer of their characteristic Nitrogen-fixing root nodules.