Treat Yellowing Leaves on Broad-leaved Evergreens

Are your Camellias or Hollies showing yellowed leaves this time of year? Some leaves are naturally aging and yellowing. Other plants with yellowed leaves have a condition known as chlorosis and may include Pieris, Illicum, Rhododendron, Camellia, Ilex (Holly), Gardenia and other broad-leaf evergreens. The yellowing is typically due to one of two causes. The plants may need a Nitrogen fertilizer or they may need the application of the micronutrient Iron. 

This yellowing of foliage or chlorosis can also occur in potted houseplants such as Citrus, Ficus and Jasminum. 

How to tell?

CrabappleLandscapExperts will examine the plants carefully.

Nnitrogen Deficiency, Flordia.edu

Nitrogen Deficiency

When a plant lacks the macro-nutrient Nitrogen, older or lower leaves will yellow uniformly and often drop. The plant will transfer available nitrogen to its growth tips and new leaves.

Nitrogen Treatment

The LandscapExperts add Nitrogen by adding organic sources such as compost, well-rotted manure, fish emulsion, or commercial fertilizers. Water-soluble fertilizers designed as foliar feeders are easily mixed and sprayed onto the foliage. We also ensure that adequate Nitrogen fertilizer penetrates the soil and root ball. Our mixtures that are high in Nitrogen, denoted by the first number in the formula. The LandscapExperts always follow the directions for application to avoid over-feeding that can damage plants.

Iron Deficiency, Cornell.edu

Iron Deficiency

On the other hand, Iron deficiency symptoms are first expressed in the new growth or young leaves. Iron-deficient leaves show a characteristic inter-veinal chlorosis, with the leaf blades turning pale green to yellow, but the veins remaining dark green. Iron deficiency often goes along with Zinc and Manganese deficiencies, and these are all micronutrients that plants need for good growth. The new leaves are not producing enough green chlorophyll because of the lack of the essential micro-nutrient, Iron, which is a component of the chlorophyll molecule.

Iron Chelate Treatment

Iron Chelate (pronounced KEY-late) is a nutritional supplement that provides a soluble source of “liquid iron” that is immediately accessible to plants. It is commonly used as a foliar spray to treat the symptoms, and provides quick and easy correction of iron deficiencies. The leaves typically green up in less than a week! Liquid Iron is chelated iron with copper, manganese and zinc. A small amount goes a long way, particularly for potted plants -- only a 1/2 teaspoon per quart of water is advised.

Fast-acting Iron Chelate is often mixed with seaweed and other organic formulations as a broad spectrum tonic for plants. Repeat monthly. It aids in the production of vigorous dark green plant growth and corrects micro-nutrient deficiencies.