Trees at Pencarrow: Re-measuring the conifer collection

by David Burdekin

Pencarrow, near Bodmin, has a fine collection of trees including many conifers that are hardy in Britain. In 1834 Sir William Molesworth who was a keen collector of rare specimens to adorn his estate paid £25.00 for an Araucaria araucana. It was at the planting ceremony that the common name was coined when a notable lawyer, Charles Austin. having carelessly handled the plant remarked feelingly, ‘It would be a puzzle for a monkey’. Sir William’s original plans were laid out in 1842 with plantings mainly centred around the drive and like other enthusiasts he bought most of his specimens from nurserymen such as Veitches of Exeter who obtained their seed from seed collectors and explorers of the time. As a side issue, one of Veitches’ main collectors was William Lobb who was born on the Pencarrow estate where his father worked as a carpenter.

Over succeeding decades much happened, with more specimens being planted and many lost in storms. In 1970 Alan Mitchell, the much revered arborist from the Forestry Commission, listed and measured the heights and girths of many of the largest trees. The following decade in 1988, David Hunt, another tree specialist, this time from Kew, re-measured many of the trees, (61 in total), tagging them with identification labels and establishing a detailed computerised list. In 1990 the severe gales damaged many of the trees throughout the estate breaking the tops out of some and felling others completely. At least 16 of the trees recorded by David Hunt near the main drive have been lost except for a Cryptomeria japonica elegans that is growing horizontally. Most of the lost specimens have been replaced over the following years

As part of garden record being prepared for Pencarrow in 2005 by the CGT, I re-measured many of the specimen trees in the northerly section of the main drive. These can be more readily identified than those in other areas (particularly the rarer species) as David Hunt noted down their exact position along the drive and away from the drive. Even though a number of labels has been lost most could be recognised from their botanical characters and their position. A total of 20 trees was measured, 16 previously measured by Mitchell and/or Hunt. An extract of one of the tables indicates the time frame of measurement (see end of article). Amongst the tallest were a deodar cedar, Cedrus deodara, (No.018), height 29.7m/girth 3.39m; a western red cedar, Thuja plicata, (No.024), height 29.4m/girth 4.89m and a Japanese red cedar Cryptomeria japonica, (No.053), height 29.5m/girth3.60m.

pencarrow_table

Other trees that were measured were at the cross roads on the main drive, and other prize specimens found elsewhere in the garden. Most were identified from their labels or from their position and allied botanical features. Near the cross roads are a large Douglas fir, Picea menziesii, (No.574), height 28.5m/girth 3.64m and the first tree east of the cross roads a good sized monkey puzzle, Araucaria araucana, (No.561), height 23.5m/girth 2.67m. A short avenue of monkey puzzles can be found on the opposite side of the road from the main gate to Pencarrow.

Elsewhere there is a number of trees of special interest. On the main lawn between the car park and the main house are two majestic cedars, (No.305), Cedrus atlantica, height 21.5m/girth 3.34 and (No.313), C. deodara, height 20.5m/girth 3.45m. There is also an unusual Taxodium nutans, (No.224), height 13m/girth 1.51. Mitchell records it as rare and this specimen may be the oldest in the country. Nearby is an old (for the species – it was introduced into Britain in 1948 after being discovered in China for the first time in 1941) dawn redwood, Metasequoia glyptostroboides, (No.225), height 18m/girth 2.70m. The tallest tree found at Pencarrow in 2005 was a Sitka spruce, Picea sitchensis, (No.203) at 39.5 metres. This tree is some 20 metres back from the north end of the main drive in a wooded area with other coniferous species.

It is interesting to compare the average growth rates for all the trees measured in the two periods (1970-88 and 1988-2005). The average increase in height growth between 1970 and 1988 was 23.5% and between 1988 and 2005 it was 16.9%. Whereas the average increase in girth for the same periods was 17.5% and 25.2%. This accords with the well established observation that as trees grow older they increase in girth more than height. Perhaps this applies not only to trees!