QuestionI am in Lancaster PA soil has high limestone content I just read that the mulch around pin oak tree can also be reason for the tree dying, I am removing the mulch< Question: can I do anything else to save this tree????
AnswerI do not think it is the mulch. It likes acidic soils, and does not tolerate limestone or shade very well. Mulch like pine straw will raise the acidity of the soil. Soil that is naturally high in lime, or calcium carbonate, is called calcareous soil, and it often has a pH above 7.5. A pin oak planted in calcareous soil is highly susceptible to iron chlorosis. Although ways exist to lower soil pH so a pin oak can receive iron oxide more effectively, lowering the pH is impractical if not impossible if the soil contains lime. The pH of soil that doesn't contain lime usually can be lowered by adding sulfur. Commercial products containing both sulfur to lower pH and soluble iron to correct iron deficiency are available.
Iron chelates, chemicals that bind with iron, can help increase iron's availability to pin oak roots. Typically, iron chelates are placed in holes 6 inches deep and at least 1 1/2 inches wide. The holes are spaced 1 foot apart around the tree in two to five concentric rings; the number of rings depends on the tree's size. Iron chelates or chelates containing iron and sulfur also can be sprayed on a pin oak's leaves, but covering all of a large tree's leaves is difficult, and the result may be only temporary.
