Botanic Gardens Trust, Sydney, Australia

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Dragon's blood tree

Last year the large old dragon’s blood tree Dracaena draco in the Palm Grove appeared to have developed a lean. A closer look revealed that it had moved in the ground, toppled slightly, and was resting on two large Syagrus romanzoffianum palms. The old ‘tree’ (actually a woody monocot) was planted in the 1860s in what is now the Palm Grove. Although it is old and fragile, it still has some good years left and so it was quickly decided to try and save it.

We immediately called in Bill Goddard from THS (Total Height Safety). THS specialise in the design and manufacture of structural support systems for trees that ‘need a little help’. They have designed several such systems for trees in the Garden before, including the two old Brachychiton rupestris in the Lower Gardens that were both on the verge of collapse a couple of years ago.

The first job was to prevent the tree falling any further, so THS installed a temporary system using strapping, winches and two palms in the opposite bed as anchorage. After this, THS started the design process for the permanent system. Calculating where the supports are fitted on to the tree is vital. Too low and the tree could fail at the roots and ‘upend’, too high and the limb(s) could break. The design and manufacture process took several months to complete, and after fabricating off site, it was finally installed in April 2012. The system comprises two stainless steel collars fitted closely around the limbs, with heavy duty Dyneema fibre ropes connected to two large timber poles in the bed opposite. Dyneema is a synthetic fibre which is stronger than a steel rope of the same dimension but less than a tenth of the weight. It is rated to 24,200 kg, and needs to be 3.5 metres above the path to allow for vehicle access underneath.

This is a good news story and like the bottle trees, timely action and investment in good quality advice and work will mean this old tree will carry on providing interest to visitors to the Palm Grove for many more years.

 

 

Dragon's blood tree

Dragon's blood tree

Dragon's blood tree

Dragon's blood tree