Gardening, Guest Posts, Planting, Plants

Plant Nutrients: Everything You Need to Know

plant nutrients guide

In addition to their basic needs, such as light, air, water, and balanced temperatures, plants also need a wide variety of nutrients in the soil for healthy growth. Air and water provide oxygen, hydrogen, and carbon that plants desperately need, however, in the soil plants require both macronutrients, secondary nutrients, and micronutrients.

Plants’ appearance are a great way of determining whether your soil is adequate and providing enough nutrients. A balanced mixture of what your plants need will make sure that you have a healthy and flourishing garden.

But what specific hydroponic nutrients do plants need?


Relating to nutrients that plants need in bigger quantities, macronutrients are more frequently needed for crop fertilisation.

  • Phosphorus. Vital for seed germination and plant growth. A deficiency of this nutrient causes plants to be dull and to have leaves of a purple or bronze colour with brown edges. Too much phosphorus can cause a potassium deficiency.
  • Nitrogen. Stem and leaves need nitrogen for appropriate growth. Too much of this nutrient causes a potassium deficiency. Yellow-green leaves with reduced growth are a sign of nitrogen deficiency, and both cold and wet soil can aid in its dilution.
  • Potassium. Increases disease resistance, however, too much potassium causes magnesium and calcium deficiencies. On the other hand, a potassium deficiency stunts growth.

Secondary Nutrients

These nutrients are often needed by most plants in lesser amounts than the macronutrients, but still required due to the latest clean air and environment efforts.

  • Magnesium. Enzyme reactions and chlorophyll production need magnesium. Not enough of this nutrient can cause leaves to fall off after yellowing. Too much of this nutrient causes a calcium deficiency.
  • Sulphur. Important for the formation of chlorophyll. A sulphur deficiency slows plant growth and causes leaves to fall. Excessive amounts of sulphur turn the soil acidic.
  • Calcium. Calcium is needed for appropriate root growth and a deficiency stunts roots, making plant leaves grow small and round and eventually fall. Too much calcium causes a potassium and magnesium deficiency.

growing seeds


Needed in much smaller amounts, micronutrients are activators for important plant functions, and necessary for healthy plant development.

  • Manganese. Allows chlorophyll formation, with a deficiency typically causing white specs on leaves or yellow leaves with green veins. Too much manganese will cause iron depletion in the soil.
  • Zinc. Without zinc, plants can’t produce proteins adequately, which will condition plant growth and maturity. A deficiency makes plants have yellowing, deformed leaves with dead spots and green vein. Too much zinc is often not a problem, as plants can withstand high amounts of this nutrient.
  • Iron. Oxygen transfer and chlorophyll formation require iron. Yellow leaves with green veins are a sign of iron deficiency, although uncommon, can cause the soil to become acidic and the leaves discoloured.
  • Chlorine. Essential for photosynthesis and gas exchange, helping to balance the potassium levels. A chlorine deficiency threatens plant health due to inhibiting photosynthesis, and chlorine toxicity scorches the leaves.
  • Boron. Helps plants’ cells take in water, reproduce adequately, and interchange sugars. If there isn’t enough boron for plants, the latter will become distorted with hollow stems and misshapen fruit. Varying from plant to plant, boron toxicity can cause stunted growth and yellow-brown leaves.
  • Copper. Important for plant reproduction and protein production. Blue-green leaves are common with copper deficiency, while root growth is restricted with toxicity. Too much copper can cause zinc, molybdenum, or zinc deficiencies, and eventually leads to plant decay.
  • Molybdenum. Essential for nitrate enzymes and legume nodule formation, low amounts of this nutrient can make leaves develop wither yellow mottling or dead spots. Molybdenum toxicity is rare but, when it happens, it reduces the absorption of nutrients like copper.

Make sure to keep an eye on your plants to diagnose any nutrient deficiency or toxicity. Plant nutrient boosters can greatly benefit your plants from seed to fully grown. Similar to humans and animals, plants also need a varied and balanced ‘diet’.

Craig HollandCraig Holland is the brand marketing manager at Plant-Magic. Although his initial dream was to become a pilot, he settled for the lively and vivacious world of plants. He has years of experience in caring for plants and writing about it and when he’s not doing that he can be found eating super noodles and cheering for Liverpool FC.