Feeding houseplants involves providing them with the nutrients they require for growth and good health. Plants need an adequate supply of the three major nutrients (macro-nutrients) and small amounts of trace elements (micro-nutrients). These nutrients are required for the various biochemical processes that take place in a plant. If these nutrients are missing or are inadequate, the houseplants will present with deficiency symptoms (poor growth). An excess of these nutrients will also cause problems for your houseplants.
The macro-nutrients are needed in relatively large amounts. They include Nitrogen (N), Phosphorous (P), Potassium (K), Calcium (ca), Sulphur (S), Boron (B) and Magnesium (Mg). The micro-nutrients are needed in small amounts. They include Iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn), Chlorine (Cl) and Molybdenum (Mo).
Nitrogen is the leaf maker. It gives the plant a lush, green foliage and also promotes growth.
Phosphorous is the root maker. It helps in root development and plant growth. It also helps in the transfer of energy from sunlight to plants and also to hasten maturity.
Potassium is the flower maker. It encourages bud formation and flowering. Potassium also increases vigour and disease resistance of plants.
Calcium is essential for root health, growth of roots and development of leaves.
Magnesium is a key component of chlorophyll (the greening material of plants) which is essential for photosynthesis (plant's food making process).
Sulfur is a constituent of plant proteins and is involved in energy production for plants.
Manganese is necessary for many plant biochemical processes.
Iron is needed for chlorophyll formation.
Copper is an essential constituent of plant enzymes.
Zinc helps in production of plant hormones necessary for stem elongation and leaf expansion, among many others.
Boron is a major constituent of plant cell membranes.
Molybdenum is essential for enzyme synthesis and activity.
Chlorine is required for energy reactions in the plant.
Most houseplants foods commonly called fertilizers are nearly always compound fertilizers containing Nitrogen, Phosphorous and Potassium. They come with a label stating the content of each of these elements; if there is no statement for one of them, then it is missing. The best fertilizer for houseplants need to be a balanced fertilizer like 20-20-20 for N-P-K. Some contain some micro-nutrients in small quantities.
If a houseplant lacks these nutrients it will develop what are called deficiency symptoms which vary from one houseplant to another. These symptoms include;
Always be careful when feeding to avoid damaging your houseplant; fertilizer is not the solution for all houseplants problems. If a houseplant is fed with too much fertilizer, it will exhibits certain signs which include;
Both macro-nutrients and micro-nutrients are obtained by the roots from the soil. Certain conditions are required for houseplants to obtain these nutrients from the soil.
These are deposited on the surface of the soil where they dissolve and get into the soil every time the houseplant is watered.
They come in the form of liquids, powders or crystals. They are applied by mixing them with water during watering; this saves time by combining two activities to be performed at once.
These are applied by spraying on the houseplant foliage. Most foliar feeds contain micro-nutrients.
Do not gamble, look up your houseplant's food requirements in this Houseplants A-Z Guide.