Kings Pride needs iron to make chlorophyll, which is necessary for photosynthesis. If the green chlorophyll does not develop early, the leaves look yellowish-green and have yellow veins. This is called iron chlorosis. In severe cases of iron chlorosis, the yellow leaves turn nearly white.
Adding iron to your Kings Pride by spraying iron products is typically a temporary solution. The best long-term solution for lawn iron deficiency is to correct the soil pH.
What does low iron do your Kings Pride lawn?
Alkaline soil, compacted soil and high levels of phosphorus from excessive fertilisation can all interfere with the ability of grass to receive the iron it needs from the soil. Cold weather suppresses the activity of microbes, which in turn reduces the uptake of iron. Excessively dry or wet soils and lack of sunlight can also reduce iron uptake.
Reducing Soil pH
Soil pH above 7 is alkaline, while soil pH below 7 is acidic. The best pH for Kings Pride is 6 to 7. Iron deficiency is more serious in grass grown in alkaline soil with a pH of 7.5 or higher. If your grass is showing symptoms of iron chlorosis, do a soil test to confirm that a high soil pH is the likely cause of iron deficiency. Lowering the soil pH can be a longer-lasting solution compared to using an iron fertiliser, although it is difficult to permanently correct alkaline soil.
Using elemental sulfur in the soil is one way to lower soil pH. Naturally occurring soil bacteria utilise the elemental sulfur, creating sulfuric acid as a byproduct, which lowers soil pH. However, once the bacteria have used all of the elemental sulfur, the soil pH will likely increase.
Adding dilute concentrations of sulfuric acid to irrigation water or applying elemental sulfur to soil will lower the soil pH and increase the ability of grass to absorb iron naturally found in soil. Too much sulfur can damage Kings Pride so follow the application rates closely.
Applying Iron To Lawn
Spraying products containing chelated iron on grass will improve its colour for two to four weeks, but the Kings Pride quickly absorbs the iron that is removed when the grass is mowed. Concentrated forms of insoluble iron oxide applied directly to soil are relatively inexpensive, but they are not effective in high pH soils where iron deficiencies typically occur.
Chelated Iron Fertiliser for Lawn
The most common form of iron fertilizer for grass is water-soluble chelated iron. Chelated iron contains iron or iron and aluminum paired with sulfate. Examples are ferrous sulfate, ferric sulfate or ferrous ammonium sulfate.
The green may last only a few weeks in cool, wet weather and for several months in cool, dry weather.
There is no doubt that iron makes your Kings Pride greener, but if you follow the application rates on any good NPK granular fertiliser you’ll be in good shape. Give your local Kings Pride grower a call if you have any questions