This important feature ran the duration last year through Hort Week on the website for an encouraging 6 months, 6 days to be exact, and more recently is featured within the RHS Plant Review Journal, both in different formats, and that being the case here for the HPS.
Although not a (hardy perennial) in the true sense, nevertheless less an indicator species for Climate change and how this may affect certain other trees, shrubs, and perennials, and how we as Gardeners adapt to these changes in our choice of planting, approach, and techniques. This depends on the variation in soil, aspect, in relation to the UK location.
I’d always been very used to the fact that Trachycarpus fortunei (Chusan Palm) central & southern China was as tough as old boots and could withstand winter temperatures of at least – 15 ° and beyond. During my time in the Cotswolds as Head Gardener, I’d witnessed -10°C and they sailed through it!
Here, the South Lakes has delivered the opposite set of circumstances from cold, to extreme warm and dry, and that’s been the strongest test!
March last year was exceptionally dry in the South Lakes, during April the dry spell continued with an increase in temperatures, the tin lid was put upon the previous two months in May which resulted in drought conditions.
This knock-on effect gave rise to soil moisture deficits with the driest conditions for that time of year since 1961. The low reservoir levels were causing concerns about sources of water, with a detrimental effect on wildlife.
This 5-metre tall Trachycarpus was adversely affected as the fronds from the green tip growth down to the middle section of the trunk turned a very significant brown in stages, eventually dying back completely.
Each day I used a trickle hose in a vain effort to try to revive this section of the palm as it slowly became desiccated.
I decided to hard prune the dead fronds away as it was clear the environmental conditions had caused extreme die back. After pruning the dead fronds away, I fed with a palm fertilizer. The intermittent rain during June contributed towards the Trachycarpus becoming a more appealing and attractive palm tree to view from the various focal points of the garden. The fronds at the tip of the Trachycarpus had become revitalised. Growth from the denuded trunk however will not be replaced.
The growth rate of Trachycarpus fortunei is 15 – 30 cm per year, and this can depend upon these factors –
* Tree quality.
* Climatic conditions.
* Degree of shade.
* Soil drainage.
From last season’s environmental responses from the tree, it appears that heat and drought pose a greater threat to a species normally recognised as being very resilient.
Aspect / exposure of course also plays a big part on the outcome. Another Trachycarpus in a more sheltered spot of the garden was completely unaffected from the adverse conditions.
Kevin Line is Head Gardener/ Horticulturist, Lakeside Garden Cumbria. Member – Professional Gardeners’ Guild.
