I am very fond of greenery and plants. But I don't have much knowledge of maintaining them. So I prefer low maintenance plants. They will live longer with my kind of a person. But the problem is much deeper I suppose. I was going through the internet where I found this lovely article about why do plants turn yellow. It was very informative in terms of the reasons stated in it. For a layman, when ever a plant is turning yellow, we think its because of water scarcity or excess sunlight or less sunlight majorly. But its very interesting that there are ample reasons as to why our plants turn yellow. So here I am stating those reasons with a hope that it will be of some help to you all.

Chlorosis

Known as chlorosis, the yellowing of plants' leaves can point to a variety of health problems. It's the visible result of too little chlorophyll, the pigment used by plants to trap sunlight for photosynthesis. Since chlorophyll gives leaves their green color, an inadequate supply turns plants a pale green, yellow or yellowish white. And since chlorophyll is key to plants' food-making abilities, a plant suffering from chlorosis might not survive if the source of its chlorophyll shortage isn't addressed.

At first glance, a yellow leaf may not seem to hold many clues about the underlying problem. But if you know what to look for, a few variables in how chlorosis develops can offer a surprising amount of information.

Reasons and fixtures

Nutrient deficiency

Beyond hydrogen, carbon and oxygen, plants need more than a dozen mineral nutrients to survive, all of which must come through their roots. A soil test is the best way to know what's missing, but a quick look at the leaves can shed light on the situation. Plants with nutrient deficiencies often have distinct patterns of chlorosis, like green veins with yellow tissue in between, that first appear on particular leaves.

  1. Potassium deficiency: Edges and tips of the leaves become yellow.
    How to fix: Bury citrus rinds in soil at base of the plant. Add compost rich in veggie or fruit waste.

  2. Nitrogen deficiency: Tips and center veins of the leaves become yellow.
    How to fix: Add organic compost like manure or coffee grounds to the soil.

  3. Calcium deficiency: Leaves become misshapen.
    How to fix: Determine if your soil is acidic or alkaline. For acidic soil use lime and for alkaline soil use gypsum.

  4. Zinc deficiency: Leaves show signs of light discoloration between large veins.
    How to fix: Spray with kelp extract.

  5. Iron deficiency: Leaves become yellow and have small green veins.
    How to fix: Make the pH of the soil 7. Then reduce the amount of phosphorus in the soil.

  6. Magnesium deficiency: Leaves show signs of white strips along veins.
    How to fix: Add organic compost rich in magnesium or add Epsom salts or lime to the soil.

Pests

Unlike a nutrient deficiency, whose symptoms are often distributed symmetrically in plant tissue, pest problems tend to develop in asymmetrical patterns. That includes damage by insects as well as leaf spots, a common indication of fungal or bacterial disease in plants.

Insect damage can lead to chlorosis in affected leaves, but it can also be managed safely with nontoxic methods like insect-repelling plants, neem oil and DIY organic pesticides. Most garden bugs are harmless or even helpful, though.

There are several safe ways to control fungi in the garden, from crop rotation to baking-soda spray, but one of the first steps is often to manage soil moisture. Plants need water to grow, of course, but too much water can create favorable conditions for fungal pathogens.

How to fix: Spray plant with neem oil or an insect killing soap.

Water and light

 Even without harmful fungi, overwatering and underwatering can both lead to discolored leaves. That may seem confusing, but there are usually context clues about which is to blame. The soil around an over watered plant is likely to be wet, for instance, and vice versa. Too much water may also lead to limp, floppy foliage, while the leaves of dehydrated plants are typically dry and brittle.

Over watering : Leaves look yellow and wilted

How to fix: Poor soil drainage can result in your plant's roots drowning. Add sand or soil to replant to a raised bed.

Dehydrated: Leaves look dry and easy to crunch.

How to fix: Water your plants regularly.

And don't forget about the sun. All the water and nutrients in the world won't help if a plant is too short on sunlight, which can make its leaves droop and fade. Many garden plants like tomatoes and cucumbers need at least six hours of sun per day, preferably eight. But sunlight requirements vary among different kinds of plants, so do research on what your garden needs. Some plants, like broccoli and salad greens, can get by with significantly less direct sunlight per day.

Lack of sunlight: Leaves look faded and droopy.

How to fix: Re position your plant's location.

Now when these reasons are known to you and me, what are we waiting for? Lets get to work and plant more trees and maintain them for a healthy surrounding.