Oaks: Episode II

Jan 17, 2022

I wrote about the wonders of oaks in a previous issue. TL;DR: If you don’t have an oak, plant one; if you already have one, plant another. With that established, today I’d like to touch on what kind of oak to plant and how to plant it.

First, a little celebrity worship:

Bedford Oak. Credit: June Marie, Flickr Commons.

This white oak (Quercus alba) in Bedford, NY is estimated to be more than 500 years old. In other words, it was sprouting around the time Magellan was leading the first expedition to circumnavigate the globe. Its “wingspan” is 120 feet and its trunk is 30 feet around. And, mind you, this is neither the largest nor the oldest specimen in the U.S. Mighty oaks from tiny acorns really do grow.

Choosing

Therein lies one of the bigger concerns, I think, about planting oaks. Those of us who live in cities or close-in suburbs just don’t have the space for a Bedford-like behemoth. We need something on a more manageable scale. North America is home to a hundred or so native oak species. Comprehensive lists, disaggregated by region, can be found at the back of Doug Tallamy’s The Nature of Oaks. For the purposes of this article, I’m going to highlight a few that are small by Quercus standards – if only to reassure you they exist:

Quercus ilicifolia (bear oak). Native range is southern Maine west to New York, south to Maryland & in the mountains to eastern West Virginia, southwestern Virginia, & western North Carolina. 12-20’ tall.
Quercus incana (bluejack oak). Southeastern Virginia to central Florida, west to east and central Texas, and north to southeast Oklahoma. Up to 55’.
Quercus margaretta (sand post oak). Texas, Oklahoma and Missouri east to Florida and Virginia. 32’ (but “occasionally to 87’” 🙄!).
Quercus prinoides (dwarf chinkapin oak). New Hampshire and Florida west to Iowa and Oklahoma. 25’.
Quercus havardii (Havard’s oak). New Mexico, Oklahoma, and Texas. 3-30’.
Quercus turbinella (shrub live oak). Southwestern Colorado to southern California, south to western Texas and Arizona. 6-12’.
Quercus vacciniifolia (huckleberry oak). California, Nevada, Oregon. 5’.
Quercus parvula (Santa Cruz Island oak). Coastal California. 50’.

There are of course dozens of other small oaks, not to mention intermediate and large ones. In addition to the Tallamy book, your local native plant society will be one of the best sources of advice.

Planting

When it comes to planting your oak, you also have choices: balled-and-burlapped trees, acorns or saplings.

If you need instant gratification, you can just go to your local nursery and buy a large tree. It will come balled and burlapped. Be forewarned, however, that large trees are expensive and the process involves severing most of the root mass. Oaks are all about their roots, so it can take years for the tree to recover.

Wild Ones, a national native plant nonprofit, says, “An oak tree planted as an acorn will catch up with a 3” caliper, 18’ tall tree in a decade at virtually no cost and will be a more resilient tree in the future.”

So if you’ve got time and patience, try planting an acorn shortly after it drops in the fall. Apparently the best way to do this is in a pot covered with chicken wire to protect it from squirrels and other acorn-lovers. The pot should be deep, though, because oaks put all of their energy in their first year into growing deep roots. They’ll grow ten times the amount of root as leaf biomass in those early months. Fill the pot with a blend of local soil and potting mix and plant the acorn about a half an inch deep. Protect the pot from extreme cold by trenching it in the ground or piling leaves or compost around it. Water it lightly once a month. In the spring, once the seedling has expanded its first true leaves but before it becomes root-bound, transplant it into the ground.

Between these two extremes is the option of planting a sapling or bare root whip. These are inexpensive and would typically include the full taproot, which will help with growth and overall health. Note that both the saplings and the acorn seedlings may need ongoing protection from marauders for the first few years.

A Scientific Experiment

My friends Caryn and Mike from Arlington, VA are lucky enough to have four healthy oaks in their yard, and they’ve used all three of the planting strategies described above. They’re also very good sports. To test the hypothesis that acorns will catch up with ball-and-burlap trees, we deployed the elite Bees’ Knees research team, equipped with cutting-edge instruments, to take some highly technical measurements at their home.

The Elite Bees’ Knees Research Team Displaying Cutting-Edge Instruments. Credit: Mike.

We used the Indiana Division of Forestry methodology (explained here) to estimate the height of Caryn’s and Mike’s trees. Newsletter size limits prevent me from including the full “data set” here, so I’ll forward that as an addendum for the nerds among us. Meanwhile, here’s the gist of the findings:

Mike and Caryn have one white oak planted as an acorn, two willow oaks planted as saplings, and one willow oak planted as a balled-and-burlapped tree. I was rooting for the tree planted as an acorn to win the race, but its average rate of growth is so far kinda lagging. This could be because it’s a different species than the others , or because it’s the most recently planted, or…who knows? We’ll need to check back on its progress in another few years. Meanwhile, the two willow oaks planted as short, spindly saplings are growing at a faster rate than the one planted as a 25’ ball-and-burlap specimen and, over 20 years, one of them has already caught up in size (despite a 19’ height disparity at the start). The other former sapling is right on their heels.

The upshot is this: when we get around to planting some oaks in our own yard, I’m going to go with saplings from a modestly-sized species (tbd). I may try planting an acorn or two for kicks, but I’m not convinced I have the patience (or lifespan!) to really see that approach through. Whichever type of oak or planting strategy you use, know that hundreds of animal species will thank you for providing invaluable food and habitat.

The Bees' Knees

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