Many people like to have some trees in their landscape. Our property has both white and pin oaks (a member of the red oak group). I recently saw an oak gall on a small pin oak. This is created when a mother wasp finds an oak twig to which she attaches her egg, and her growth-regulating chemicals on the egg induce the oak to grow a home for the grub. The grub will eat the interior tissue of the gall until it matures and chews its way through the outer shell. The hard gall shell can persist on the twig for a long time until it eventually drops to the ground. Oak galls are also known as oak apples by some people.

I happened to be reading a book that noted that most historical documents were written with iron gall ink. This ink is made from oak galls, iron sulfate (ferrous sulfate), gum arabic, and water. This type of ink was widely utilized in the colonial period and well into the 19th century for important documents, manuscripts, and legal records. The ink used on the original copy of the Declaration of Independence, which is housed in the National Archives in Washington, D.C., is primarily iron gall ink. This ink was commonly used during the 18th century. Iron gall ink was even used to create many medieval historical documents.

Would you believe that there was a link from an oak tree to our Declaration of Independence?

Oaks trees are usually shown as a symbol of a strong deep-rooted tree that can withstand almost any weather. They have been used to symbolize courage, endurance and wisdom.

The Bible even refers to the oaks of righteousness and tells Christians we are solidly founded in Christ no matter what hardships come our way. The word oaks occurs four times in the Bible. It refers to mighty men (Exodus 15:15, Ezekiel 17:13), rams (Isaiah 60:7), and trees.

Oak trees are also good for pollinators. They don’t provide traditional nectar like other trees and flowers, but honeybees and other pollinators still favor them. Oaks secrete a substance similar to nectar to attract pollinators. As a result, oak trees aren’t prone to many pests and diseases.

However, oak trees can be attacked by some diseases. Oaks are divided into two groups, the red oaks and the white oaks. Red oaks (pin, black and northern red) are more susceptible than white oaks (white, bur, swamp white) to a wilting disease. Infected red oak trees can wilt and die within several weeks, while white oaks may survive for one or more years.

If you see wilting browning leaves at the top of the tree, your tree may have oak wilt, which is in our area. A correct diagnosis is critical to reducing the spread of the disease. Since other diseases and problems can be confused with oak wilt, we recommend getting a diagnosis and having the tree(s) inspected by a certified arborist.

To learn more about oaks in Ohio, go to: http://go.osu.edu/treesofohio

To learn more about oak wilt, go to http://go.osu.edu/oakwilt

Eister is an Ohio State University Extension Master Gardener Volunteer in Mahoning County.