Yellow Plant Leaves

Michelle RobertsGardening


There are a number of reasons for yellow plant leaves. Yellowing on mature bottom leaves is not always a problem as they tend to yellow, turn brown, and drop off due to lack of sunshine or close contact with a wet soggy ground, or just because they have lived their life and are done. However, when yellowing occurs throughout the plant, it is the first visible sign that something is wrong. Figuring out the problem and solving it can be critical to the life of the plant as well as the quantity and quality of fruit or vegetable production.
[spacer height=”10″ mobile_hide=”true”]

Possible Causes:

[spacer height=”10″ mobile_hide=”true”]

Over fertilization

Too much use of chemically based fertilizers can cause a toxic environment in the soil and cause yellow plant leaves, followed by stunted growth and death. If you are using chemically based fertilizers be sure to follow recommended rates of application so as not to poison your plants.

Too wet

Yellow plant leaves are also cause by too much water. If the roots have not begun to rot, the problem can be corrected by backing off the water and allowing the plant to dry out between waterings.

Bug invasion

Pests can cause plants to turn yellow as they feed on the leaves and stems robbing the plant of essential nutrients. Some of the pests out there – like spider mites – are so tiny and difficult to see, that you don’t realize your plants are being munched until it is too late.

Inspect yellowing leaves by turning the plant leaf over and using a magnifying glass to see if there are colonies of mites inhabiting the leaf. Controlling pests requires hand picking (as in the case of squash vine bugs) or regular spraying. If your soil is balanced your pest problem will diminish.

Nutrient Deficiencies

Plants will turn yellow if the soil is not balanced. There are 3 major nutrients (nitrogen, phosphorus, and potassium) and micro nutrients (13 minor nutrients including magnesium, calcium, iron, manganese, boron, and more) that a plant needs in order to be healthy.

Yellowing leaves can be and often is a sign that the major or micro nutrients are lacking. A lack of Nitrogen will turn the leaves yellow. If the plant is suffering from nitrogen deficiency the yellowing will start from the inside of the leaf and work its way out. If the plant is suffering from potassium deficiency the yellowing will start from the edges of the leaves and work its way in.
[spacer height=”20″ mobile_hide=”true”]

Nitrogen Deficiency

YellowPlantLeaves [spacer height=”20″ mobile_hide=”true”]

Potassium Deficiency

YellowPlantLeaves [spacer height=”20″ mobile_hide=”true”]

Yellowing can also be caused by iron chlorosis, deficiencies in magnesium, manganese, and zinc. These are all micro-nutrients, and also need to be in balance. If you practice good crop rotation as well as providing a balanced supplement of minerals to the soil every year, you won’t have a lack in these nutrients. Azomite is just such a mineral supplement and can be purchased at Roberts Ranch and Gardens or you can purchase it at some ranch and garden stores. Also, don’t forget to add calcium to your soil. Calcium makes all other nutrients more available to the plant. Azomite is also a source of calcium.

By frequently taking a critical look at your garden plants you will learn to recognize deficiencies at early stages. If you quickly supplement your soil with whatever is lacking, you will be able to reclaim your plant without much trouble.

For a list of organic soil amendments and other self reliant information, become a member of Roberts Ranch and Gardens at where you can access valuable information on gardening in the member resource section.
[spacer height=”20″ mobile_hide=”true”]