Even for a plant geek like me, I have to admit that there are some perennials/shrubs/trees so commonplace that they fly below my radar, that I take for granted in spite of their fine qualities. The oak would be at the top of my list of overlooked, under-appreciated plants. Which is unfortunate, because they not only make good shade trees and are easy to grow, but they are hugely beneficial for all manner of wildlife, and a great number of oaks show off good color in the fall!
Of the 400 or so species of oaks that inhabit the world, 90 are native to the United States. Oak trees belong to one of two groups: white oaks (characterized by rounded lobes on their leaves) and red oaks, which feature pointed lobes on theirs. White oaks produce a lighter, less consistent crop of acorns, but the acorns contain less tannin and are therefore more palatable to wildlife, though wildlife will still consume red oak acorns in years when white oak acorns are limited in availability. The red oak group takes two years to mature their acorns, but are more consistent and produce a heavier crop.
White oak group (species common to the Mid-Atlantic and southeastern states):
- White oak (Quercus alba)
- Bluff oak (Quercus austrina)
- Swamp oak (Q. bicolor)
- Overcup oak (Q. lyrata)
- Bur oak (Q. macrocarpa)
- Swamp chestnut oak (Q. michauxii)
- Chinkapin oak (Q. muehlenbergii)
- Chestnut oak (Q. montana or Q. prinus)
- Southern live oak (Q. virginiana)
Red oak group (species common to the Mid-Atlantic and southeastern states):
- Scarlet oak (Q. coccinea)
- Northern pin oak (Q. ellipsoidalis)
- Southern red oak/Spanish oak (Q. falcata)
- Pin oak (Q. palustris)
- Willow oak (Q. phellos)
- Northern red oak (Q. rubra)
- Shumard oak (Q. shumardii)
While I always knew oak trees are good sources of food for birds and squirrels, I didn’t know until recently that oaks support over 500 species of butterflies! And many produce nice fall color, particularly the scarlet oak and northern red oak, with fiery reds, though most other oaks do show at least some color. The ease of growing oaks from seedlings depends on the species, some are difficult to transplant because of a deep taproot, while others are easier because of a more fibrous, spreading root system. Most oaks are not particularly fussy about soil, though I have read that some don’t like high pH (alkaline) soils.