Scarlet Oak: Good growth, gorgeous giant

People often look for fast growing trees. I don’t blame them – we all want to see results as quickly as possible in our landscape. Oaks are not generally considered to be fast growing trees, perhaps because people have heard that hardwoods need slow growth to produce “hard” wood. There are some fast growing oaks, however, especially in good garden conditions such as residential landscapes. Scarlet oak (Quercus coccinea) is one such oak.

Scarlet oak (Quercus coccinea)

Scarlet oak is native to the eastern US from Maine down to north Georgia. It does well in poor soils and grows fast in full sun conditions. Growth rates can exceed two feet per year, allowing this tree to reach maturity in 20 years, one of the earliest oaks to do so. Top size is 100 feet but most trees are 60 to 80 feet tall - a good sized tree to provide shade for you and acorns for wildlife.

Scarlet oak is part of the “red oak group”. Oaks are divided into two groups, the red oak group and the white oak group. Oaks in the red group have bristle tips on their leaves and acorns that take two years to mature. The acorns you see on the ground today were formed from flowers the previous year. Tannin content in these acorns is higher than that in the white oak group, so animals generally prefer eating acorns from oaks in the white oak group first, leaving the red oak group acorns for later in the year.  

A sample of scarlet oak leaves early in the season

Scarlet oak looks rather similar to red oak (Quercus rubra), but careful examination of the leaves and in particular the acorns will show the difference. Note: trying to identify an oak from a single leaf or a single acorn (especially one without the cap) is not recommended.

Leaves on any individual tree may have deeper sinuses than other trees (the sinus is the indented area between the lobes on the leaves), and leaves on even the same tree may vary. The leaves shown on the left came from several different trees. Also, the leaves are not as red as they might been had they stayed on the tree longer.

Scarlet oak acorns

A good identification feature of the acorn is a set of grooved concentric rings around the tip of the acorn. You may need a hand lens to see it. The cap of the acorn usually has overlapping shingle scales that are tightly pressed down - almost as if they were glued down; sometimes they appear a bit shellacked in comparison to Q. rubra acorns.

Now is a good time to look for and collect acorns if you find a particularly beautiful tree. Collect at least 20-30 as some of them will likely have oak weevils inside. Put them in a bowl of water and discard any floaters - they have weevils. If you want to see the critter - put them in a box and the worm will crawl out after a few days (a fun activity for kids), leaving a small exit hole. Put it outside when you discover it so that it can continue on it's way.

Quercus coccinea

You can also buy scarlet oak at nurseries. As an outstanding and popular tree, it is often available in sizes up to 2 inch caliper. Ask your local nursery about it. Nuttall's oak (Quercus texana) is a good substitute if they don't have scarlet oak. The color won't be as intense, but it is also a fast grower and a good color in the fall.