Quercus palustris Seeds | Pin Oak
LATIN NAME: Quercus palustris
COMMON NAME: Pin Oak
Plant Profile
Pin oak is a fast-growing deciduous oak of the eastern and central United States, reaching twenty to twenty-five metres with a straight trunk and a distinctive crown: the upper branches rise, the middle ones spread and the lower ones droop, giving the tree a pyramidal shape that persists into middle age. Its leaves are deeply cut into five to seven lobes with bristle tips, glossy dark green in summer and bronze-red in autumn, and they often stay on the tree into winter. The acorns are small, round and set in a shallow cup, and they take two years to ripen. The tree grows on wet flats and along streams in its native range, and it is one of the few oaks that tolerates poorly drained, compacted soil, which is why it was planted in streets and parking lots across the world.
Science & Biotechnology
Quercus palustris belongs to the red oak group, the section with bristle-tipped leaves and acorns that mature over two seasons, and it hybridises with several relatives where ranges overlap. Its tolerance of waterlogging comes from aerenchyma in the roots, which allows oxygen to reach the tissue in saturated soil, a trait rare among oaks. The species is, however, intolerant of high pH: in alkaline soil it develops iron chlorosis, with yellow leaves and dieback, and many of the street trees planted in limestone regions in the twentieth century declined for that reason. Its acorns are eaten by wood ducks, wild turkeys and squirrels, and the tree is an important mast species in bottomland forest. Oak wilt and bacterial leaf scorch are the main disease risks, and the species is relatively resistant to gypsy moth.
Uses & Benefits
The tree is planted as a street tree, a park tree and a shade tree for wet ground, and its autumn colour and symmetrical shape make it a good specimen for a large lawn. The wood is hard and heavy and is used for construction, flooring and firewood, though it is not as valuable as white oak. Its acorns feed waterfowl and mammals, and the tree supports a large number of moth and butterfly larvae, which makes it valuable in a wildlife garden. It is not a tree for a small garden, since the roots are shallow and wide, and it lifts paving. It should be planted only in acid to neutral soil, and it needs space for a crown that can be fifteen metres across.
Growing from Seed
Collect acorns in autumn as soon as they fall and sow them immediately, since they lose viability if dried. Sow two centimetres deep in a deep pot of loam, leaf mould and grit, and leave the pots outdoors through winter. Germination occurs in spring, and the taproot runs fast, so plant out or pot on early. Grow in full sun. Plant out into moist, acid soil in autumn, and water through the first two summers. Keep a ring of clear ground around the trunk for three years, and mulch with leaf mould. Avoid alkaline sites entirely, and do not stake unless the tree is exposed, since a moving stem thickens faster.
Our Take
A fast oak for wet, acid ground, with a crown that droops at the bottom. Plant it only where the soil is not alkaline.
Related Reading
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