Bumper Crop of Acorns

Sunday, November 11, 2018 9:24 AM

What is up with all the acorns this year? When the wind blows it sounds like hail hitting the roof! NM

I was raking leaves off the patio recently, and I don’t remember the last time I needed a shovel to pick up all the acorns. So, at least in my yard and the yards of my neighbors, I agree, this year we seem to have more acorns than usual.

However, just because some of us are experiencing a bumper crop, this may not be true throughout the region. These “mast” years (as these large acorn crops are called) can be very localized as the main contributor to fruit production is the weather and as we know, weather can vary depending on your location and particular microclimate. However, one large oak having a particularly good year can drop up to 10,000 acorns in a mast year. And, yes, that can get noisy on the roof!

The primary weather factors affecting acorn development are spring frosts, summer droughts, and fall rains. When the oak trees determine the danger of a spring frost has passed, they begin to flower. Oaks are what we call monoecious. This means that a single oak contains both male and female flowers.

If you have an oak tree in your yard, you are probably familiar with the male oak flower as they are those long, worm-like growths that contain a number of flowers arranged like beads on a string. These flowers produce the pollen that tends to give our patios and cars a green tint in the spring. In contrast, the female flowers are quite small and often resemble leaf buds.

The spring winds blow pollen from tree to tree pollinating the female flowers. Interestingly, the acorns of white oaks mature within the year while acorns of red oaks mature over a period of two years.

Some of these acorns may grow up to become oak trees, but others will serve as a source of protein for blue jays, wild turkeys, rodents, deer, and bears. Secondarily, if we have a year of larger than normal acorn production, depending on the reproduction cycles of the animals, we can expect surges in the populations of mice, squirrels, chipmunks, deer, bears, turkeys etc.  While this may be good news for some, unfortunately, a rise in mouse and deer populations can secondarily contribute to an increase in the tick population as well.

Even though the noise from the shower of acorns can be unsettling and the quantity we need to clean up in our yards a nuisance, these acorns remain an important part of our natural ecosystem.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.