Pin oak is native to central and North / East of America and is widely planted in the UK as an ornamental tree. It was introduced into the UK in the 1800's. There are several Pin oaks in the Princesshay shopping district as well as on the Catherdral green in Exeter. It is one of the fastest growing species of oak capable of growing up to 61cm (24 inches) per year. Although it is a fairly easy tree to grow and establish it is not tolerant of Alkaline soil.
Pin oak is also known as swamp oak as it thrives in damp lowlands, rivers, streams and other bodies of water. The name Pin oak may refer to its historical use where wooden pins were sometimes made for the construction of wooden buildings. It is a is a medium sized tree and deciduous in nature. Typically a mature Pin oak will reach heights of up to 22m but there have been recorded cases of 28m. As the tree matures the lower branches tend to grown downwards which doesn't make them a very good choice as a street tree. The crown typically remains pyramidal in shape making this quite a unique tree amongst hardwood species. Unlike most Oak species the general lifespan of Pin oak is quite short - usually around 120 years.
During the autumn the leaves will turn deep red / brown
The young leaves will be present during the flowering season which is usually March to April time
The leaves are 5–16 cm long and 5–12 cm and have the characteristic lobbed shape of oak leaves. Each leaf has five or seven lobes and each lobe has five to seven bristle-tipped teeth. The leaves are similair to that of Red oak however the sinus (gap between each lobe) is almost U shaped. The leaves are virtually hairless with only a small pale orange-brown down on the underside around the central vein. During the late spring the flowers will emerge and are often unnoticed. The male flowers are yellow / green drooping catkins and the female flowers are small green / red and held closely against the twig. The male flowers are much easier to spot than the female flowers during the Spring as the young leaves and male flowers often obscure the presence of the female flowers. The flowers are wind pollinated and require other nearby Pin oaks (or compatible members of the Red oak family) to successfuly cross pollinate.
The buds are small, pointed, and chestnut brown in colour
The lobbed leaves are pointed and the sinus (gap) between the lobes is almost U shaped
The acorns are held in half round cups and are 10–16 mm long and 9–15 mm wide. They can take up to two years to fully mature and quite often you will see young and mature acorns on older trees. For most oak trees they begin to produce acorns at around 40+ years of age but for Pin oak it's usually 20+years. They usually begin to drop from the tree in late August to September. The acorns are an important food source for wildlife quite often grey squirrels.. In the wild the acorns are often dispersed by spring flooding but in the UK the acorns are more likely to be dispersed by jays and squirrels.
The bark of Pin oak becomes rough and furrowed as it matures
The acorns are held in half round cups and are 10–16 mm long and 9–15 mm wide and take up to 2 years to mature
As Pin oak is not native to the UK and was introduced in the 1800's there isn't a lot of history or myths around this lovely species of Red oak. Although it has been used in the production of timber the quality of the wood is not as good as Red oak. In the UK they are only planted as ornamental trees in green spaces. They do not grow well in elevated areas and prefer wet lowlands but will be quite happy in the many parks and green spaces around the UK.