Right now, oaks, walnuts and many other trees are growing “flowers” that will become nuts this fall. These flowers are currently releasing a great deal of pollen into the air which can cause great distress to people who suffer from seasonal allergies. The pollen also coats everything around such as outdoor furniture, decks and automobiles.
All of this pollen comes from the male and female flowers that are located at the end of the branches where new leaves are sprouting. The male flowers dangle in cylinders from the ends of twigs that grew the previous year. They are a pale yellow and are botanically referred to as “catkins.”
The female flowers of the oak also emerge from the same twig, but they are not as numerous as the male flowers. They grow out of the stem end or axils of the new leaves. The female flowers are pollinated by male flowers with the help of the wind.
The female flowers of the oak will eventually turn into an acorn. The male flower, after it has released its pollen will fall off the tree.
Oak trees are divided into categories – red oaks and white oaks. In Missouri, there are 13 oaks in the red oak group. Within the red group are commonly known oaks such as black jack oak; sawtooth oak and willow oak.
There are eight species of white oak in Missouri. Commonly known among white oaks are burr oak, chinkapin oak and post oak.
The red oaks are known for acorns that take two years to reach maturity. Red oak acorns require a cold, moist winter to germinate. The inside of a red oak acorn has a seed that’s coated with a wooly hair. The kernels of the red oak acorn are bitter. Additionally, the scales that cover the acorn are thin.
White oak acorns mature at the end of their first growing season. These acorns do not require a cold treatment for germination, and many of them will actually germinate in the fall after falling on the ground. White oak acorns have a smooth interior and a thick outer shell. The seed inside is sweet in comparison to the red oak.
Common to the Ozarks are traditional white oaks, Quercus alba, and red oaks, Quercus coccinea. White oaks are considered to be the gold standard by which all oaks are compared, but red oaks are also very handsome with a beautiful red color in autumn.
Questions or comments related to gardening? Contact Joleen at missourigardener@hotmail.com.