Natural Iron Fertiliser
Optifer is an effective iron and micro-nutrient fertiliser made from the bark of fir trees and other plant substances. The resulting form of iron is a natural chelate which is better absorbed and tolerated by plants than other synthetic iron forms. Optifer also contains valuable sulphur and trace amounts of manganese and magnesium.
Nutrient content - 6%Fe,4.5%S,.1%Mn,.1%Mg
As a rule of thumb, plants which prefer a low pH soil are plants with a larger appetite for iron. It is no coincidence then that a plant's uptake of iron is dependent on the pH of the soil. Overly alkaline (high pH) soils will limit the amount of iron the plant can uptake and cause deficiencies. This is the most common cause. Other factors which can inhibit iron uptake are: too much clay in the soil, a high phosphorous content and wet compacted ground.
Plants most often affected by iron deficiency include: Rhododendrons, Hydrangeas, Orchids, Blueberries, Camellias, Gardenias and Citrus.
Symptoms - The most common symptom is iron chlorosis which shows first as a yellowing of leaves between the veins. Leaves then become fully yellow and start to turn brown and die. Foliage on some species can develop a bleached or ivory white colour tone. As iron is not a mobile nutrient within the plant the symptoms of iron deficiency will first appear on young foliage.
Iron Deficiency in Blueberry
The best way to address the deficiency is by lowering the soil pH. This can be done by adding organic matter, peat, or elemental sulphur. Lowering a soil's pH takes time however, so using a liquid feed will supplement the plant's iron needs whilst soil pH is being corrected. It is also an ideal substitute when amending the soil pH is not practical.
- Shake bottle thoroughly before use.
- Add 3-10ml of Optifer to every litre of water used (.3-1% solution).
- Spray onto foliage evenly ensuring to cover the underside of the leaves. Do not apply on flowers as it they may be stained.
- Best done in the morning when leaves are wet with dew but will be readily absorbed by leaves as long as conditions are not very hot and dry.
- Use every two weeks of the growing season.