The symptoms of iron chlorosis may be very prevalent in certain species of trees at this time of year. It tends to affect a short list of our Denver Landscape plants, however the effects of this nutrient deficiency can be detrimental to the overall health of the plant with the potential of an early demise.
Iron chlorosis is the lack of chlorophyll in the leaf. The nutrients plants require to manufacture chlorophyll are nitrogen, magnesium and iron. The symptoms of iron chlorosis begin with the leaf fading to yellow, while the veins in the leaf remain relatively green. The symptoms are most often apparent in the newest growth during early summer. Without the tree receiving a form of iron every year, the symptoms will progress with the scorching of the leaf tissue. If the tree does not receive treatment, the advancement of the disease leads to canopy dieback. There are situations where the deficiency is not solely due to an iron deficiency, but could also be related to a manganese deficiency. This particular deficiency is for the vast majority correlated to only maple trees. For scientific determination between the deficiency resulting from a lack of iron or manganese, tissue sampling would be required.
Our area has high alkaline clay soils with adequate levels of iron available in our soils. However, due to the levels of our soil pH and clay content the iron becomes a form not available for plant uptake. Plant material has different nutrient requirements and some plants are better adapted for iron uptake, particularly in our soil types. There are many plants that are tolerant of our high pH, alkaline clay soils and perform without exhibiting symptoms. Examples: Honeylocust trees or Kentucky coffee trees. There are also plants that are tolerant of our high pH, alkaline clay soils and may survive, but not thrive, nor perform up to their true colors, as they do in other parts of our country. Examples: rhododendrons and hydrangeas.
There are times where the soil may not solely be to blame. There are times, a plant may have a girdling root issue (often this is below ground and a challenge, if not impossible to identify). Girdling roots in essence restrict the flow of nutrients and water from the root system up into the canopy of the plant.
Trees in the Denver landscapes susceptible to iron chlorosis include (but are not limited to): silver maple, ginnala maple, red oaks, and autumn blaze maple.
For more information please visit the following links:
Your Denver tree specialist has options ready and available for the treatment of this nutrient deficiency. While not all trees are good candidates for treatment, many trees under a regular treatment regimen are responsive. Please contact our office today to have one of our arborists put a plan in place with recommended treatments if your tree is diagnosed with iron chlorosis.