Institute of Food and Agricultural Sciences
Hendry County Horticulture News
Oaks in Florida
There are nineteen species of oaks native to Florida. However, only a few species of oaks are common in our area. Oaks are excellent landscape trees, providing deep shade that can assist in cooling dwellings in the summer. Although some many may exhibit brilliant autumn foliage almost all of our local species remain leafy green throughout the winter. On good sites, oaks can grow relatively quickly, providing landscape and shade values within five to ten years. There is significant variation among species, some including the water oak are relatively short-lived, where as live oaks more than 500 years old have been documented.
Oaks are divided into two groups: the white oaks and the red (or sometimes black) oaks. The white oak group includes species with acorns that mature in the fall of the year they are formed (annual oaks). White oaks generally have a rounded leaf tip and rounded lobes without bristles. Their acorns are sweeter than those of the bitter red oak group, making them more palatable to both humans and wildlife. The red oak's leaf lobes are usually pointed or tipped with a fine bristle. Their acorns mature the second year following their formation, leading to the designation as biennial oaks.
The predominant member of the white oak group in our area is the live oak. The majestic, moss draped live oak (Quercus virginiana) may reach heights of 40 to 50 feet with trunk diameters of three to 4 feet. Their low, massive branches provided naturally formed, angled wood valued in building the wooden ships of the 1800s. Live oaks are common on sandy soils throughout the state. Unlike most other oaks, the live oak retains its leaves until after the following year's leaves have appeared. This habit results in an "evergreen" tree. Leaves are lustrous green above and pale-pubescent on the underside. Leaf length varies from two to 5 inches with width ranging from ½ to 2 ½ inches.
The inch long, brownish black acorns, are borne on stalks usually in clusters of three to five. Live oaks are among the more long-lived oaks, frequently living for 200 years or more. Their longevity and spreading nature make this species one of the most valued oaks for a variety of landscape applications.
The red oak group includes several other species of oaks which occur locally. The most common of these is the medium sized laurel oak tree (Quercus laurifolia) which typically reaches heights of 50 to 60 feet, though trees as tall as 100 feet have been recorded. The slender branches form a broad, round topped, dense crown. Laurel oaks are found on sandy soils near streams and swamps from North Carolina south into Florida. Unfortunately, the laurel oak is short lived and often begins to decline after 50 or 60 years making it less desirable for landscape use than the live oak.
Although the leaves remain on the tree through much of the winter, they generally fall in early spring leaving the tree bare of leaves for several weeks before the new leaves appear. Laurel oak leaves are lustrous green above and pale below with a yellow midrib. The ½ inch long acorns are generally solitary, commonly sub-sessile and egg shaped.
The leaves of the water oak (Quercus nigra), a tall, slender oak, are semi persistent, falling a few at a time throughout the winter. This persistence may give the appearance of an evergreen habit, but leaves do not persist into the second growing season. Leaves are extremely variable in shape and size but are generally shaped like a spatula, narrow at the base and broadly rounded near the tip. Both upper and lower surfaces of the leaf are green and smooth.
Acorns are solitary or occasionally in pairs. This widespread species is commonly found around LaBelle and may be mistaken for a live oak by the uninitiated. Water oaks may obtain a fairly large size - 50 to 70 feet in height is average but they are weak and short-lived and generally do not perform satisfactorily in the landscape.
The myrtle oak (Quercus myrtifolia) is small, evergreen oak is commonly found in coastal areas and sandy ridges throughout Florida. Thick forests of wind sculptured myrtle oaks are common where development has not yet occurred. It is a small tree, seldom reaching more than 35 feet in height with diameters generally from four to 8 inches. The one to 2 inch long leaves are oval to oblong, leathery and both surfaces are smooth, dark green and shiny. The acorns are very small, about a ½ inch in diameter, and grow in pairs or clusters. Their small stature makes myrtle oak an excellent choice for landscape plantings and they should be used more widely where space is limited.
The Shumard Oak (Quercus shumardii) is native from Maryland as far south as central Florida, although it can be planted far south of its native range. It is a large, attractive tree, reaching 90 to 125 feet on ideal sites on deep, rich soils along streams and riverbanks. This commonly planted landscape tree has leaves which display a classic "oak leaf shape" with six to 11 deeply sinused bristle tipped lobes. The foliage of Shumard oaks is dark green above and paler green below and turns a deep crimson red in autumn; making it a valued ornamental.
Some people may decide against planting oaks for
reputation for slow growth. With good care, this is not true and
these American natives provide a hardy, picturesque, pest free trees that
will ensure that oak trees will grace our vistas in the future.
Good luck and good gardening.
Gene McAvoy is the horticulture agent with the Hendry County Extension Service. Direct your horticulture questions to PO Box 68, LaBelle, FL 33975, e-mail - firstname.lastname@example.org or phone 863-674-4092 or 863-983-1598. You are also welcome to visit the Hendry County Extension Office at 225 Pratt Blvd., LaBelle. Office hours are from 8:00 - 5:00.
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