Why Do Plants Need Fertilizers?

Indoor Plants

House plants need fertilizers. Outdoor plants can get their nutrients from the soil
House plants need fertilizers. Outdoor plants can get their nutrients from the soil | Source

Plants Are the Only Living Thing that Can Make Their Own Food

All plants have the capability of making their own food. Plants are the only living organisms that can make their own food. Outdoor plants have a greater ability to do this, more than indoor house plants do.

Plants use sunlight and the chlorophyl (green in their leaves) to manufacturre sugars from carbon dioxide.They use the sunlight and the green in their leaves to make sugars from carbon dioxide (which they breathe in through their leaves during the day) and water.

They breathe in the carbon dioxide through their leaves during the daylight hours. This sugar is then used by the plant energy so that it can grow and flourish. This is the important process of photosynthesis. The plant uses most of the energy to make new plant material, and some of it is stored by the plant for use during the months when there is less sunlight.

How Plants Make Their Own Food

At night, plants breathe in oxygen, a process called respiration. The soil provides the plant with minerals to help it grow. The plant releases any water that it doesn't need into the air through its leaves. This is called transpiration.

Plants use the process of photosynthesis, plants manufacture the sugars and carbohydrates needed for their growth and development. They require at least 16 elements to carry on this process. Plants obtain carbon, oxygen and hydrogen from air and water.

Outdoor plants would obtain the other nutrients required for growth from the soil. Houseplants rely on us to supply these nutrients through the application of fertilizers. Underfertilized houseplants often exhibit symptoms of slow growth, weak stems, pale leaves and reduced flowering.Plants are meant to grow in the right conditions.

With proper soil and good care, plants just naturally grow. However, fertilizer can be a helpful addition to help the plant along. The most important chemical elements of good plant growth is potassium, phosphorus and nitrogen. At times, plants may have a tougher time accessing these nutrients. That's where fertilizer works well.

Fertilizers typically contains nitrogen, phosphorous, potassium (N-P-K) other elements, which are needed in lower quantities, are usually readily supplied in the soil.


Organic and Inorganic Fertilizers

Organic and Inorganic Fertilizers:
organic fertilizers come from nature, such as seaweed extract, wood ash, and fish meal.
inorganic fertilizers are nutrients that are added to the plant soil. Commercially sold fertilizers are labeled with three numbers. Each of these numbers tells you the percentage of nitrogen, phosphate or phosphorus, and potassium or potash in the fertilizer in that order. The three numbers are usually written like this 10-10-10. Each nutrient has a specialized function.

  • Nitrogen encourages healthy foliage growth
  • Phosphorous encourages root growth
  • Potash encourages bigger, healthier blooms

Other macronutrients that are good for your houseplants include: boron, calcium, manganese, and magnesium that will encourage better growth. Macronutrients are chemicals the plant needs in a larger amount. Copper, iron, and zinc are micronutrients that the plant also needs. Micronutrients are needed in smaller amounts by the plant.

Fertilizers come in different forms

  • liquid
  • sticks
  • tablets
  • granular
  • slow release

Plant Food Helps Plants Flourish

Plants respond well to proper fertilization
Plants respond well to proper fertilization | Source

Learn About Fertilizers

Liquid and slow release are the best for indoor house plants. Granular is best of outdoor use. Sticks and tablets offer the most convenience, but they don’t do as good a job of distributing the nutrients to the plant.

To use liquid fertilizers, add the proper amount to your watering can. Based on the directions you can use it every time you water or every other time.

Of these, the two best suited for indoor use are liquid and slow-release fertilizers. Sticks and pills seem convenient, but they don't distribute nutrients very well through soil and, once you've shoved a fertilizer stick into your pot, you have no control over its release. Granular fertilizers are really designed for outdoor use.e Slow release fertilizers like Osmocote are in a tiem releae shell the lets the nutrients leech into the soil over a period of time. Osmocote lasts about 4 months. Slow release fertilizers are more expensive because they have a long lasting effect.

In general, house plants appreciate fertilizers that are high in nitrogen. Flowering plants respond best to those with higher phosphorus included as part of the fertilizer.


Whatever fertilizer you choose, follow the direction on the label. Too much fertilization can harm you roots and leaves.


Houseplants respond to fertilizer during the season they are growing actively. Usually this is from March through October. In the winter months, the temperatures are lower, and the daylight hours are shorter. Generally you do not have to fertilize your plants during the winter months.

Proper Plant Care


How can you tell if you have overfertilized your plants?


  • browning roots

  • browning leaf ends

  • wilting plant

  • leaves that are poorly shaped

  • white crust on the rim of the pot


To counteract the effects of overfertilization:


  • leach the fertilizer from the soil with lots of water to wash out the excess salt levels.

  • repot the plant and replace it with fresh soil


Fertilizers Play an Important Role in Plant Care

Plants use th nutrients to help their roots, stems, flowers and leaves. Fertilizers are important to help a plant grow and flourish. It is important to educate yourself about feeding your plants. The results will help your foliage look better and grow bigger.

More by this Author


Comments 3 comments

twitteringbird profile image

twitteringbird 4 years ago from Kerala, India

hi, it is interesting. Good luck


VirginiaLynne profile image

VirginiaLynne 4 years ago from United States

Terrific information on plants. My husband is a plant scientist and so lots of people ask him for help when their plants are not looking good. Often, it is too much water or the wrong amount of fertilizer.


toknowinfo profile image

toknowinfo 4 years ago Author

Hi Twitteringbird, Thank you for stopping by and commenting.

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working