Quercus palustris 'Pringreen', sold as Green Pillar®, is a narrow columnar selection of the Pin Oak. It reaches around 14 metres tall but holds to roughly 3 metres wide, which is the entire point of the tree: it gives you the scale, shade and autumn colour of an oak in a footprint that a standard Pin Oak could never fit into.
The glossy dark green lobed foliage turns through bronze to deep red in autumn before dropping, leaving a tidy upright branch framework through winter. Growth is upright and naturally even, so a planted row grows up matched without shaping.
It wants full sun and adapts to a wide range of soils, including heavier ground and sites that hold moisture for short periods, which is characteristic of Pin Oak. Frost hardy, wind firm and tolerant of urban conditions once established.
Specified for driveways, narrow verges, car park rows, tight streetscapes and avenue planting between buildings, and useful as a strong vertical feature in a garden where a spreading oak would take the whole space.
Also sold as: Green Pillar Pin Oak, Green Pillar® Oak, Upright Pin Oak, and Quercus palustris 'Pringreen'. 'Pringreen' is the registered cultivar name and Green Pillar is the trade name, so the two refer to the same tree.
Green Pillar or a standard Pin Oak? Same species, same foliage, same autumn colour, very different footprint. Quercus palustris is the classic broad pyramidal Pin Oak and needs open ground to develop properly. Green Pillar holds to about 3 metres wide, so it is the one for a driveway, a narrow verge or anywhere a full-width canopy will not fit. If you want a columnar oak but prefer the English Oak leaf and habit, Quercus robur 'Fastigiata' is the alternative.
Frequently Asked Questions
About Green Pillar Pin Oak
What is Green Pillar Pin Oak?
Green Pillar is a named columnar selection of Quercus palustris, the Pin Oak, registered as the cultivar 'Pringreen'. It carries the same glossy lobed foliage and deep red autumn colour as the species but holds a narrow upright form, reaching around 14 metres tall and only about 3 metres wide.
Is 'Pringreen' the same tree as Green Pillar?
Yes. 'Pringreen' is the registered cultivar name and Green Pillar is the trade name it is sold under, so Quercus palustris 'Pringreen' and Green Pillar Pin Oak are the same tree.
How is it different from a standard Pin Oak?
Width. A standard Pin Oak develops a broad pyramidal canopy and needs open ground. Green Pillar holds to about 3 metres wide at a similar height, so it fits driveways, narrow verges and planting between buildings where the species would be unusable. Foliage, autumn colour and hardiness are the same.
How big does Green Pillar grow?
Around 14 metres tall by 3 metres wide at maturity, which takes several decades. Plan for the height rather than the width, and keep it clear of overhead powerlines even though the footprint at ground level is small.
When does it colour in autumn?
Through autumn the glossy green foliage moves through bronze into deep red before dropping. Cool nights and a bright, dry autumn give the strongest colour, while a mild humid autumn produces a softer and shorter display.
Is it suitable for a driveway or narrow verge?
This is exactly what it was selected for. The narrow crown keeps clear of vehicles and buildings, the even upright habit means a planted row matches up, and the trunk can be lifted for clearance. Still allow proper soil volume for the roots, and keep it well clear of underground services.
How far apart should Green Pillar be planted?
Plant 3 to 4 metres apart for a tight avenue or driveway row, or 4 to 5 metres for individual trees that read separately. The narrow crown allows much closer spacing than a standard oak.
Is it deciduous?
Yes. It drops its leaves through late autumn and stands bare over winter, revealing a tidy upright branch framework, then leafs out again in spring. Young pin oaks sometimes hold dry brown leaves through part of winter, which is normal and passes with age.
How do I care for it?
Water deeply through the first three summers, mulch widely and keep turf off the root zone while it establishes. Prune only in late winter, removing damaged wood and lifting the lower branches gradually to the clearance you want. Do not attempt to reduce the height, as topping ruins the form.
