18th December 2023


Peter Coles


Vicky Schilling Bursary report

Much of September was taken up writing my report on a couple of years of recording mulberry trees with support of the Vicky Schilling Bursary that I was awarded by the Tree Register of the British Isles (TROBI) in 2021. A special focus during the bursary period was on Syon House, which boasts no fewer than 9 veteran black mulberries in a private orchard belonging to the Duke of Northumberland. We will write about these shortly. I see our relationship with TROBI as ongoing, and as Morus Londinium casts its net wider across the UK, we will add more old trees to the Register, including, I hope, more champions.

Black mulberry in the water meadow at Syon House. Was it part of an old orchard or an ornamental tree?

A characteristic of black mulberries of course is that, by the time they have grown enough to be potential champions (the main focus of TROBI), they have often collapsed, spread out in all directions and have multiple trunks arising from former branches through layering. It’s hard to know what to measure, as girth and height have little meaning compared, say, to a single-stemmed oak, ash or elm. One metric seems to be crown spread, as this can be measured for an upright (maiden or pollard) as well as a recumbent or layering tree. 

For anyone recording mulberry trees for us (or TROBI) a 15m or 30m surveyor’s tape measure is usually good enough. Measure girth (at chest height (1.5 m)) if possible, but below the first branches and underneath any burrs or wounds that would inflate the measurement. For multiple stems you can measure them all (there’s a formula to calculate the single stem equivalent) and/or you can measure the base of the tree. Some mobile phones have an inbuilt app to measure height using the camera’s rangefinder or LIDAR.

I use a third-party app called Arboreal Tree designed for Swedish foresters. It costs about £20 but is worth it (and you can measure 5 times for free).­The next step up is a laser hypsometer weighing in at over £400, or a pocket clinometer for about £125 that requires some trigonometry calculations. Few mulberries are taller than 12 metres so a rough guess might be close enough (though TROBI prefers maximum precision).

Balliol mulberries revisited

Balliol College, Oxford, claims to have the oldest black mulberry tree in the city, dating back to King James VI & I’s English silk venture and was planted around 1609-11. Merton College also has a black mulberry planted around the same time. The Balliol tree is hanging on with just a few slim slivers of its original bole and seems to be layering from one of its branches.  It still produces plenty of fruit, and has been used as the origin of scions in Garden Quad and the Fellows’ Garden.

The black mulberry in Garden Quad was planted around 1609

This mulberry was planted by Queen Mary in 1921

Princess Margaret planted this mulberry in 1951

A scion of the King James I mulberry in Fellows Garden?

A second mulberry in Fellows' Garden


In the next blog: On the trail of the red mulberry

All text and photos (c) Peter Coles


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