Why do oak trees produce lots of acorns some years?

Thanks to Nancy and Rob Hontz for their great question: Why did their live oak trees produce so MANY acorns in 2016?

They’ve swept countless gallons of acorns from hardscape surfaces, and are dealing with a deluge in their lawn and garden beds.

Pruning last year did not create this exceptional bounty.

There are a few different reasons involved, including differences in species and planting time. In my yard, the red oak is producing a lot more acorns than the live oak, while my Monterrey oak produced almost none, so while the general trend this year is oak trees that are virtually raining acorns, the situation is variable.

The issue is also climate-related: after many years of drought, we’ve had two years of abundant rainfall, giving trees more ability to grow, photosynthesize, recover, and reallocate resources for future generations.

There’s also an evolutionary connection here. Nut-producing trees have developed a cyclical reproduction habit which has been shown to keep the population of nut-eating animals, such as squirrels, off balance. Fewer nuts one year will curb critter populations, so that the next time the tree has a “good” year, there won’t be as many consumers and more nuts will have a better chance to survive and grow into new trees. This cycle is irregular, so it may be a number of years before the problem is this “bad” again.

In addition to their questions, Nancy and Rob also sent along some of the tricks they’ve developed for dealing with the issue. After laborious, virtually futile attempts to rake the acorns, they decided that they had to take more drastic steps.

First, they installed some inexpensive nylon netting on one corner of the tree, keeping the nuts from landing on the ground in the first place.

Next, they purchased a nut-gathering tool, such as those marketed for collecting pecans, to see if it would also work on acorns, and it did! How did I not think of that?! Thanks Nancy and Rob, I will definitely be stealing your idea.