Fertilizer
/ˈfɝː.t̬əˌlaɪ.zɚ/
Definition
Fertilizer is a substance added to soil, potting mix, or water to supply mineral nutrients that plants need for growth. It differs from a soil amendment because its main role is feeding the plant, not improving soil structure. Most products provide the primary nutrients nitrogen, phosphorus, and potassium, and some also include secondary nutrients and trace elements such as iron or magnesium.
Use in Gardening
- Nutrient balance matters: Different products supply different proportions of nitrogen, phosphorus, and potassium, which influence leafy growth, root development, flowering, and fruiting in different ways.
- Too much can harm roots: Excess fertilizer raises salt levels around roots, making water uptake harder and sometimes causing leaf burn, weak growth, or root damage.
- Soil and potting mix behave differently: Garden soil can hold and release nutrients over time, while container mixes lose them faster through watering, so feeding often needs to be more regular in pots.
- Timing affects results: Plants use nutrients best during active growth. Applying fertilizer when growth is slow, such as in low light or cool conditions, can lead to buildup instead of steady uptake.
Related Terms
NPK ratio
Npk ratio describes the relative amounts of nitrogen, phosphorus, and potassium in a fertilizer, shown as three numbers…
Nitrogen
Nitrogen is a chemical element and essential plant nutrient, classified as a primary macronutrient because plants need…
Phosphorus
Phosphorus, in plant science, is an essential macronutrient and chemical element that plants take up mainly as…
Potassium
Potassium is an essential plant nutrient and chemical element that plants absorb as K+. Unlike nitrogen or phosphorus…
Micronutrients
Micronutrients are essential mineral elements that plants need in very small amounts for normal growth and metabolism…
Side dressing
Side dressing refers to a fertilizing technique in which nutrients are applied to the soil beside established plants or…
Top-dressing
Top-dressing is a horticultural technique in which a thin layer of material is added to the surface of the soil or…
Foliar feeding
Foliar feeding refers to applying a diluted fertilizer solution directly to plant leaves so nutrients can be absorbed…