What is the NPK value?
As a grower, you want to give your plants the right amount of nutrients. The NPK value can help you in this. You can usually find this on the substrate packaging; it indicates how much nitrogen, phosphorous and potassium it contains. The NPK value assists in maintaining the health of your plants.
Nitrogen - N
N is the symbol for nitrogen. Nitrogen ensures the leaves and stems are nice and green. It contributes to the growth of the plant. If your plant contains too little nitrogen, the leaves turn yellow in colour. Too much nitrogen is not good either. Your plants then weaken and are more susceptible to diseases, fungi, frost and infestations.
Phosphorous - P
P is the symbol for phosphorus. Phosphorous promotes respiration, energy supply, root development, flowering and the shelf life of the crop, amongst others. If your plant contains too little phosphorous, the leaves turn purple or blue and the lateral roots do not grow well. The plant remains small. An excess of phosphorous is rare. If this is the case, it can harm the plant indirectly due to a lack of trace elements.
Potassium - K
K is the symbol for potassium. Potassium promotes the transport of carbohydrates and water, the firmness of the plant, fruit development, root development, and it makes the plant more resistant, amongst others. Too little potassium affects root development and the plant looks limp. An excess of potassium means the salt concentration is too high and the plant will absorb fewer nutrients.
How to read the NPK value
Does your substrate packaging state an NPK value of 29-18-9, for example? Then it means the fertiliser contains 29 percent nitrogen, 18 percent phosphorous and 9 percent potassium. Your plant needs all three nutrients, but a plant goes through different phases. You have to give a different amount of nutrients in each phase. For example, your plant requires more nitrogen in the growth phase and more potassium in the flowering phase.
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