Aeroponics & Yellow Leaves

Nitrogen

• A plant in an aeroponic system that is not getting enough nitrogen will have yellow leaves on the lower part of the plant. The plant's overall growth will be stunted, resulting in a plant that is shorter than it should be. The general color of the plant will be a lighter green than normal, giving the plant a sickly appearance. Plants use nitrogen in large amounts and this element is essential to proper health and growth of the plant.

Phosphorous

• Phosphorous is necessary for photosynthesis and energy transfer. Too little of it in the nutrient solution results in a plant with yellow leaves on the lower part of the plant. As these leaves die, they turn black or dark brown and drop off of the plant. As with a nitrogen deficiency, such a plant may have stunted growth, but if the problem is a nitrogen deficiency, the entire plant may appear purple or reddish. In the early stages of this problem it can look blue-green.

Magnesium

• If the lower leaves are not completely yellow, but instead are yellow on the tips of the leaves and the areas in between the veins, the problem could be not enough magnesium in the nutrient solution. The lower leaves will tend to appear wilted and will not hold themselves up. Without this element the plant cannot absorb light energy needed to photosynthesize food.

Zinc

• Zinc is a trace element that is not used in large quantities by plants, but it is essential to their well-being. It acts as a catalyst for the growth processes of plants. A zinc deficiency makes the leaves appear pale yellow and rather papery, with veins that stand out against the leaf fibers.

Iron

• An iron deficiency in the aeroponic nutrient solution will cause all of the leaves on the plant to turn yellow, but the veins in the leaves will remain green. Iron is essential in the creation of chlorophyll and photosynthesis; without it plants will sicken and die.