Scarlet oak (*Quercus coccinea*) is an oak species that grows throughout its native Midwest, Eastern, and Southern United States. Scarlet oak is popularly cultivated for its ornamental purposes, especially its colors in the fall.
I. Appearance and Characteristics
Quercus coccinea, the scarlet oak, is a deciduous tree in the red oak section Lobatae of the genus Quercus, in the family Fagaceae.
It is primarily distributed in the central and eastern United States. It occurs on dry, sandy, usually acidic soil. It is often an important canopy species in oak–heath forests. The scarlet oak is the official tree of Washington, D.C.
Quercus coccinea is a medium to large deciduous tree growing to around 5.5–7.3 metres (18–24 feet) with an open, rounded crown; the maximum height is approximately 30 m (100 ft). The trunk diameter at breast height is typically 61 to 91 centimetres (24 to 36 inches) It is a medium-size tree that grows fast and matures relatively early. It sets a deep growing taproot.
The leaves are glossy green, 7–17 cm (2+3⁄4–6+3⁄4 in) long and 8–13 cm (3+1⁄4–5 in) broad, with seven lobes, and deep sinuses between the lobes. Each lobe has 3–7 bristle-tipped teeth. The leaf is hairless (unlike the related pin oak (Q. palustris), with tufts of pale orange-brown down where the lobe veins join the central vein). The foliage generally becomes bright scarlet in autumn. The flower color is yellow to green, depending on the season.
The acorns are ovate, 7–13 millimetres (1⁄4–1⁄2 inch) broad and 17–31 mm (5⁄8–1+1⁄4 in) long, a third to a half covered in a deep cup, green maturing pale brown about 18 months after pollination; the kernel is very bitter.
II. How to Grow and Care
Sunlight
Scarlet oak thrives best in full sun, where it receives intense and direct light for most of the day. This species is highly adaptable, tolerating some shade, but growth and foliage health are optimal when bathed in direct sunlight. Scarlet oak’s tolerance allows it to survive in partial sun conditions, although such environments may result in reduced vigor and less vibrant fall coloration. Outdoors, scarlet oak should be planted in open spaces, away from taller structures or trees that could cast excessive shade. Its leaves, with a brilliant hue, manifest the tree’s adeptness at harnessing light for photosynthesis and seasonal display.
Temperature
Scarlet oak grows in a large range of temperatures. It is adaptable in hardiness zones 5-9.It prefers well drained soil with adequate ventilation in the tree canopy. Scarlet oak will not do well in standing water. Also, leaf molds pose serious threats if the leaves cannot dry out in the wind. So make sure they are not stuck against buildings where rainwater may drain.
Watering
Originating from well-drained upland forests, scarlet oak has adapted to thrive with moderate moisture availability. It exhibits a preference for consistent soil moisture but can tolerate short periods of dryness. Watering should be done once every 1-2 weeks, aligning with its ability to withstand slight drought conditions. Typically an outdoor species, scarlet oak showcases its resilience in varying climate zones by adjusting water storage during different growth cycles.
Soil
Ideal soils are well-drained loam, sandy-loam, or sandy-clay soils. Some alluvial fan areas and silts harbor good oaks stands. The key in all of these is that the soil is well-drained. Standing water cannot be tolerated by oaks.
Fertilizing
For optimal health, scarlet oak thrives with balanced nutrition fertilizers like 10-10-10 or high nitrogen formulations in early spring to kick-start growth. Seasonal variations dictate application frequency—annual spring feeding suffices, with additional mid-summer top-ups if needed. Avoid over-fertilization, which can harm scarlet oak’s root system and overall vigor. Use approximately 2 lbs of fertilizer per inch of trunk diameter, spreading evenly over the root zone. This promotes robust growth. During establishment and in early developmental stages, scarlet oak benefits most from consistent fertilization, tapering as it matures. Always water scarlet oak thoroughly post-fertilization to aid nutrient absorption and prevent root burn.
Planting Instructions
Pruning
Never prune an oak tree in the summer months. It’s best to prune an oak tree when it is dormant so you can avoid the onset of oak wilt disease. To prune an oak so that it can have more air circulation, use disinfected pruners to remove dead, diseased, weak, or damaged branches that feel brittle, have wounds, or are discolored. Also remove crossed limbs and shoots that are growing straight up or down. Prune up to 1/3 of old wood each season.
Propagation
Though it’s slow, the most common way to propagate an oak tree is by using an acorn, which is essentially the tree’s seed encased in a very tough shell. Acorns don’t typically turn into oak trees because once they fall from the tree, they are scooped up by wildlife or they lay under the tree without enough sun or nutrients to help them grow. Here’s what to do after you’ve gathered a batch of acorns late in the season:
- Take the caps off of the acorns.
- See which acorns are viable by putting them in a bowl of water for five minutes. Discard floating acorns (they are not viable).
- Now you can stratify your acorns, which means you are simulating a cold condition to trick the acorns (seeds) into germination. Dry off the saved acorns, and put them in a plastic baggie filled with damp vermiculite, perlite, peat, or sawdust. Seal the bag.
- Put the bag in the refrigerator for 45 to 60 days. During that time, look for germination of the acorns to begin.
- Put the germinated acorn in a small pot with good potting soil and keep moist.
- Keep the pot in a spot that is warm enough, but not too hot, with direct sunlight in the morning and shade in the afternoon.
- When the seedling is about a foot or so high, it can be transplanted into a permanent full sun spot in your yard.
Pests and Diseases
Common Pests & Plant Diseases
Oaks are susceptible to several pests, including leafeaters, cankerworm, forest tent caterpillars, gypsy moths, borers, and a host of other pests.
Oak wilt, a fungus disease, can cause problems with scarlet oak trees. Trees infected with oak wilt cannot be saved. Cankers can also form on scarlet oak trees. Fungal diseases can also cause heart rot.
Common Problems
Oak trees are usually unaffected by problems, except when it comes to growing in the wrong type of soil (alkaline) and suffering from the ubiquitous disease, oak wilt. Here’s what to look for:
Yellowing Leaves
Chlorosis of leaves is a sign the tree is not doing well because of alkaline soil. It’s best to amend the soil, specifically treating it with sulfur to make the soil more acidic.
Browning Leaves
Leaves that are brown at the outer edges but still somewhat green in the middle may mean the tree is suffering from a fungal disease known as oak wilt. During the spring and summer, the leaves usually wilt and fall off as a result of oak wilt. Sap beetles are known to spread this disease through the tree’s wounds. It’s impossible to save a tree infected with the disease. Prevention is best, which is why it is not advisable to prune trees between April and August when sap beetles can enter fresh wounds.
III. Uses and Benefits
- Wildlife uses
Many species of wildlife look to Q. coccinea for shelter, including small- to medium-sized birds, as well as small mammals such as squirrels. It is also a temporary home to various moth larvae throughout the year. It provides food in the form of acorns to many animals, such as woodpeckers, blue jays, squirrels, wild turkeys, white-tailed deer, and black bears.
- Medicinal uses
Quercus coccinea produces galls from insect interactions which may be used to treat hemorrhages, chronic diarrhea, and dysentery.
- Other uses
Scarlet oak has an excellent red color during the fall months and is typically grown for shade and ornamental purposes. The red oak is a popular selection for lumber and is commonly used as a flooring material.
Scarlet oak wood has a light to medium color consisting of reds and browns. The scarlet oak has a fairly coarse texture with a relatively large pore size. The durability of scarlet oak is less than the white oak, which has a higher level of decay and rot resistance. Scarlet oak lumber is easy to glue and looks attractive after staining and finishing. It has a distinct, appealing smell common with most oaks.
Oak has been classified as a sensitizer, although it does not cause many allergic reactions. Reactions include eye and skin irritations and asthma-like symptoms, but not severe.
White oak is typically more expensive than scarlet oak; red oak is in good supply with reasonable pricing, making it a very popular lumber product throughout the USA.
Scarlet oak is commonly used in furniture, cabinetry, interior trim, flooring, and veneer. Scarlet oak shares many characteristics with red oak and often falls in the same category as red oak (Quercus rubra) in a broad sense
