Largest tree burl

Tree burls are abnormal swellings on branches or stems following a disturbance to wood cells in the cambial layer under the bark. Coast redwood (Sequoia sempervirens) commonly makes burls, some of which are extremely large. However, redwood burls are worth their weight in gold, so photos of the largest ones are all we can see. Most are converted into veneers, but are also coveted by bowlmakers and other woodworkers. The largest recorded was discovered in 1977 at Big Lagoon in northern California, USA, on Louisiana Pacific property. The burl was 36 m (118 ft 1 in) in circumference, 9 m (29 ft 6 in) tall, and estimated to weigh 476 tonnes (525 US tons).

The largest preserved tree burl, meanwhile, comes from a Sitka spruce (Picea sitchensis). Discovered in 2005, the Ronning Burl from Holberg on northern Vancouver Island is estimated to weigh nearly 30 tonnes (33 US tons). The burl was cut from a 525-year-old spruce and measured 6 m wide and 6 m tall (19 ft 8 in x 19 ft 8 in), with a circumference of around 13.7 m (45 ft). It is now on display near the waterfront at Port McNeill in British Columbia, Canada.

Formerly, the largest tree burl from a Sitka spruce was estimated at over 20 tonnes (22 US tons) and also had a circumference of around 13.7 m (45 ft) when it was cut and moved in 1976. It was originally found growing at the base of a 351-year-old tree in Port McNeill and, along with the Ronning Burl, remains on display in the area to this day.