Planting Oak Trees For Wildlife and People
Planting an oak tree is the ultimate investment in the future of the earth. Oak trees are long-lived, routinely living to 500 years. Some species live for more than 1000. Throughout their long lifetimes, oaks provide shade, beauty, clean air, carbon sequestration, and many other benefits. Oak trees produce some of the finest wood in the world, so they are an investment for future generations of humans as well as the environment.
Oaks are also the most outstanding wildlife tree in the temperate world. The oak family is the host plant of over 500 species of butterflies and moths in North America alone, and is a major source of food and shelter for over 100 species of bird and mammal, including wild turkeys, whitetail deer, and squirrels.
Though eating acorns is unusual among modern Americans, acorns were a staple food of the indigenous tribes of California, and were used by other Indian tribes and early colonists both for food and as livestock feed. The legendary jamón ibérico de bellota, considered the finest ham in the world, is produced by pigs allowed to roam semi-wild in the oak forests of southern Spain.
White Oaks Vs. Red Oaks
In North America, there are two main groups of oak trees (Quercus sp.): white oaks and red oaks.
The two groups are named after the two most important species in each group: the White Oak (Quercus alba) and the Red Oak (Quercus rubra)
Native north American white oak (leucobalanus) species include:
- White Oak (Quercus alba)
- Swamp White Oak (Quercus bicolor)
- Blue Oak (Quercus douglasii)
- Bur Oak (Quercus macrocarpa)
- Chestnut Oak (Quercus montana)
- Overcup Oak (Quercus lyrata)
- Chinkapin Oak (Quercus muhlenbergii)
- Post Oak (Quercus stellata)
- Southern Live Oak (Quercus virginiana)
- and more
Native Red Oak (erythrobalanus) species include:
- Red Oak (Quercus rubra)
- Scarlet Oak (Quercus coccinea)
- Pin Oak (Quercus palustris)
- Blackjack Oak (Quercus marilandica)
- Black oak (Quercus velutina)
- Coast Live Oak (Quercus agrifolia)
- and more
If you are unsure which group a particular oak belongs to, check out the leaves. White oak leaves have rounded ends, while red oak leaves are pointed. White oaks also tend to produce larger, heavier acorns than red oaks.
Why Oak Diversity is Important
The difference between the two groups is most important for people
interested in planting oak trees to attract wildlife. White and red oak
species are important to wildlife for different reasons at different
times of year.
White oak acorns are preferred by wildlife because they are sweeter and tastier than red oak acorns. They are high in carbohydrates and help animals gain weight quickly in autumn to prepare for the winter.
Red oak acorns, on the other hand, have high levels of a group of compounds called tannins, which have a very bitter taste. When white oak acorns are abundant in fall and early winter, animals avoid the unpleasant-tasting red oak acorns. As winter progresses and white oak acorns become scarce, however, animals begin to eat more and more red oak acorns. Red oak acorns happen to be higher in fat and protein than white oak acorns - exactly the high energy nutrients necessary to help animals survive the lean months of late winter.
For this reason, if you are interested in attracting whitetail deer, wild turkeys, squirrels, or any of the more than one hundred other bird and mammal species that make use of acorns for food, it is very important to plant a mix of white oak and red oak group oak trees in your yard or woodlot.
A diverse mix of species is also important because oak trees produce large crops of acorns on different schedules. Most white oaks produce acorns yearly, while most red oak acorns take two years to mature. Some species of oaks produce bumper crops of acorns even further apart. Planting several different species of oaks from each of the two main types of oak tree ensures a more steady and consistent supply of acorns for local wildlife.