Swamp white oak natives in the central and north-central United States. This tree matures at 15 to 18 m tall and has a growth rate of 30 to 61 cm per year. The swamp white oak does produce acorns, however, the fruit does not appear until the tree is 20 -30 years old.
I. Appearance and Characteristics
Quercus bicolor, the swamp white oak, is a North American species of medium-sized trees in the beech family. It is a common element of America’s north central and northeastern mixed forests. It can survive in a variety of habitats. It forms hybrids with bur oak where they occur together in the wild.
Swamp white oak, a lowland tree, occurs across the eastern and central United States and eastern and central Canada, from Maine to South Carolina, west as far as Ontario, Minnesota, and Tennessee with a few isolated populations in Nebraska and Alabama. This species is most common and reaches its largest size in western New York and northern Ohio.
Quercus bicolor grows rapidly and can reach 18 to 24 meters (60 to 80 feet) tall with the tallest known reaching 29 m (95 ft) and lives up to 285 years. The bark resembles that of the white oak. The leaves are broad ovoid, 12–18 centimetres (4+3⁄4–7 inches) long and 7–11 cm (2+3⁄4–4+1⁄4 in) broad, always more or less glaucous on the underside, and are shallowly lobed with five to seven lobes on each side, intermediate between the chestnut oak and the white oak. In autumn, they turn brown, yellow-brown, or sometimes reddish, but generally, the color is not as reliable or as brilliant as the white oak can be.
The fruit is a peduncled acorn, 1.5–2 cm (5⁄8–3⁄4 in), rarely 2.5 cm (1 in), long and 1–2 cm (3⁄8–3⁄4 in) broad, maturing about six months after pollination. Good crops of swamp white oak occur every 3 to 5 years, with light crops during intervening years. The minimum seed-bearing age is 20 years, optimum age is 75 to 200 years, and maximum age is usually 300 years.
Because the seed of swamp white oak is not dormant, it germinates soon after falling. Seed collections should be made soon after ripening in order to delay early germination. These acorns are difficult to store without germination or loss of viability occurring. Sound acorns have a germinative capacity between 78 and 98 percent. Gravity, rodents, and water are the primary dispersing agents (4,10).
Swamp white oak may live up to 300 years.
The swamp white oak generally occurs singly in four different forest types: black ash–American elm–red maple, silver maple–American elm, bur oak, and pin oak–sweetgum. Occasionally the swamp white oak is abundant in small areas. It is found within a very wide range of mean annual temperatures from 16 to 4 °C (61 to 39 °F). Extremes in temperature vary from 41 to −34 °C (106 to −29 °F). Average annual precipitation is from 640 to 1,270 millimetres (25 to 50 in).
The frost-free period ranges from 210 days in the southern part of the growing area to 120 days in the northern part. The swamp white oak typically grows on hydromorphic soils. It is not found where flooding is permanent, although it is usually found in broad stream valleys, low-lying fields, and the margins of lakes, ponds, or sloughs. It occupies roughly the same ecological niche as pin oak, which seldom lives longer than 100 years, but is not nearly as abundant.
II. How to Grow and Care
Sunlight
Swamp white oak should be planted in a field with full sun. It gives shade, shady plants can be planted under it.
Temperature
Swamp white 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. Swamp white 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
While swamp oak prefers consistent moisture, it can withstand dry periods.
On the other hand, a newly planted tree should be watered regularly—as much as weekly—in the absence of rain for the first two summers until it is well established.
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
Besides amending the soil with plenty of organic matter before planting a new tree, the best regular fertilization you can give an established oak tree is to allow fallen leaves to remain on the ground in the autumn, adding nutrients to the soil when they decompose.
If a soil test indicates poor soil, add a slow-release fertilizer in early spring so it’s available to the tree as the weather warms up and the oak starts growing in spurts. The recommended N-P-K ratio for oaks is 12-4-8 (12% nitrogen, 4% phosphorus, and 8% potassium). Do not fertilize late in the growing season, as it will lead to extra foliage growth and make the tree more susceptible to winter injury.
Pruning
Branches should be pruned to avoid moist pockets or where heavy branches may fall on people or buildings. Avoid having branches that grow with leaves tight together or pressed against buildings. If rain collects in these pockets then molds and fungi can attack. Swamp white oak love having their leaves dry out in a well ventilated breeze.
To ensure that no danger occurs from the brittle hardwood branches, make sure that heavy branches do not hang over walking paths or outbuildings. Also, do not let children play near oaks in a thunderstorm as they are susceptible to falling branches and lightning strikes.
Propagation
It is possible to grow swamp white oak from acorns but getting the timing right can be challenging. You need to wait for a tree to drop its acorns naturally, and then collect them promptly, as they dry out within three to four days after they drop and become unviable. In light of this, it is recommended to purchase a seedling or young tree from a nursery. Swamp white oaks in containers can be planted any time between spring and fall.
How to Grow from Seeds
Growing a swamp white oak from an acorn can take several years before the seedling is large enough to be transplanted into the ground. The choice of acorn is essential. Do not use any acorns that are cracked or have holes. Soak the acorns in water for 24 hours. Discard floating acorns, which are nonviable. Here’s how to grow from seed:
- Fill a 1-gallon planting container with a drain hole with the same soil as the location where you intend to plant the tree. Enrich the soil with organic matter or compost.
- Place two to three soaked viable acorns in the container, laying them on their sides. Cover with 1 to 2 inches of soil. Water regularly and deeply.
- The acorns should start to sprout in about one month. Keep only the strongest seedling.
Overwintering
These very cold-hardy trees can tolerate freezing temperatures in their usual growing zones. Protect young saplings still in containers or newly planted outdoors with a layer of mulch or straw over the root zone.
Pests and Diseases
Common Pests & Plant Diseases
Swamp white oak is susceptible to anthracnose, canker, powdery mildew, shoestring root rot, and oak wilt.1 The tree can also get leaf spot, which is common to appear on oaks late in the season and is merely an aesthetic issue that won’t kill the tree. Leaf blister, a fungal disease that looks like little bumps on the leaves, can defoliate a tree.
Common Problems
Swamp white oak is a low-maintenance tree, but it needs to be given plenty of room to grow freely.
Yellowing Leaves
When a swamp white oak shows signs of chlorosis, the underlying cause is alkaline soil, which makes nutrients unavailable to the tree. This can occur suddenly even to a mature tree after a new structure has been erected nearby. The likely cause is nearby concrete or limestone, which increases the pH of the soil and makes it alkaline.
To avoid this condition, do not plant a swamp white oak near building structures. If unavoidable, add organic materials to the soil to reduce soil pH: peat moss, rotted manure, or rotted leaf compost, which the tree produces every fall.
III. Uses and Benefits
- Ornamental uses
Equally useful as a street or lawn tree, swamp white oak provides excellent shade with dense coverage provided by beautiful two-tone green and silver leaves that turn golden in the autumn. Its ability to attract wildlife and birds also make it desirable for planting in parks and native-species gardens. It combines well with Hosta or Rhododendron.
- Other uses
It is one of the more important white oaks for lumber production. The wood is similar to that of Q. alba and is not differentiated from it in the lumber trade.
Being in the white oak group, wildlife such as deer, bears, turkeys, ducks, and geese as well as other animals are attracted to this tree when acorns are dropping in the fall.
