Quercus palustris - Pin Oak (Fagaceae) ------------------------------------------------------------------ Quercus palustris is a very popular, symmetrical -fruit is a small acorn (0.25" long) with a cap cover- shade tree that can tolerate dry or wet sites, with ing only the very top of the small nut, on a short characteristic downswept lower branches and peduncle and often in clusters of 2 or 3 ascending upper branches. When placed in the Twigs correct pH soils, Pin Oak can grow very rapidly and -greenish- to reddish-brown, turning gray by the reach great heights at maturity. second year and somewhat thin -Pin Oak is perhaps the most twiggy of all the Oaks, FEATURES and retains dead limbs (due to self-shading) in its Form interior and lower canopy for many years unless they -large shade tree are thinned out -maturing at about 100' Trunk tall x 40' wide when -bark is medium gray, being lightly furrowed into healthy under urban middle age and beyond, and slowly becoming more conditions, but even deeply furrowed with a light reddish interior bark in larger than that in the old age wild -branches are characteristically descending (angled -upright pyramidal sharply downward) on the lower one-third of the growth habit in youth, trunk, horizontal in the midde one-third, and becoming upright oval ascending on the upper one-third, sometimes with age breaking into co-dominant central leaders by middle -medium to rapid age growth rate (most rapid -branches arising directly from the trunk are in acidic, permanently numerous, thick, of relatively small caliper, and moist soils) densely twiggy, adding to the medium texture of the Culture tree in winter -full sun to partial sun -performs best in full sun in continuously moist to USAGE wet, deep, acidic soils, but is adaptable to dry soils; Function however, it is usually exacting in its need for soils -shade tree for dry, moist, or wet sites, especially with an acidic pH (optimally between pH 5.0 and 6.5) where a stately and symmetrical growth habit in a -propagated by seeds large deciduous tree is needed (in this case an upright -no serious diseases or pests, but leaf yellowing pyramidal form, with downswept lower branches) (chlorosis) due to limited uptake of iron (and Texture nitrogen) in alkaline soils can be a serious problem -medium texture in foliage and when bare -commonly available in B&B form -thick density in foliage and when bare -member of the Red Oak group Assets -cultural treatment for foliage chlorosis includes soil -formal pyramidal growth habit acidification (rarely successful), soil fertilization with -most easily transplanted Oak (fibrous root system) chelated iron and other micronutrients (short term), -rapid growth and establishment (in acidic pH soils) or direct iron supplementation (iron sulfate or ferric -autumn color is often russet-brown to crimson ammonium citrate as pellets in capsule containers, -dry site or wet site tolerant deposited directly by boring into the sapwood of the -urban tolerant (heat, drought, pollution, thin soils) tree trunk, which does work but needs to be repeated fruits attract every 3-5 yrs.) wildlife Foliage Liabilities -alternate, medium to -leaf chlorosis dark green, with an and branch overall shape that is ovate dieback when and about 5" long, with 3- planted in high 7 prominent bristle- pH soils tipped, incised, and -fruit litter relatively thin lobes with age having very deep "U"- Habitat shaped sinuses in- -Zones 5 to 8 between -Native to the -autumn color is usually North and Eastern U.S. an attractive red-brown to russet, but sometimes an SELECTIONS outstanding crimson Alternates -most of the dead leaves -large shade trees (Acer saccharum, Fraxinus on juvenile trees hang on throughout the winter americana, Gymnocladus dioicus, Quercus alba, whereas mature trees lose most or all of their foliage Quercus rubra, Ulmus americana, etc.) by winter -trees that perform well in both dry and permanently Flowers moist to wet sites (Gleditsia triacanthos, Fraxinus -yellow-brown pendulous male catkins are obvious pennsylvanica, Q. bicolor, Taxodium distichum, etc.) and prominent in late Apr., but are ornamentally Cultivars – Variants – Related species insignificant, as are the very small pistillate flowers -Q. palustris 'Sovereign' - lower branches are Fruits horizontal to slightly downswept, instead of strongly -mature in 2 seasons downswept; this cultivar is not commonly available.