Because it is much hotter and, during the monsoon, both wetter and more consistently humid, many of our favourite temperate plants will not readily cope with these conditions. They may be built to endure several degrees of frost, but, on the other hand, will be unable to handle the full power of the tropic sun, or, in some cases, the saturated ground and moisture-laden air that is the norm during the rainy season. A plant such as lavender (lavandula angustifolia), which flourishes in the south of France and is grown commercially in huge beds, needs dry, well-drained soil and abhors clay. In Thailand, it is liable to contract root rot because the ground underfoot in the monsoon season is consistently damp.
By way of contrast, tropical plants, and especially those native to extreme climate zones (9, 10 or 11 on the horticultural scale), will not only survive here, but will grow at a rate of knots not seen in temperate climates. Indeed, some plants, introduced from less congenial climates, have become invasive in Southeast Asia, Northern Australia and the South Pacific archipelago. Lantana camara, for example, having ‘escaped’ from South America, has become a weed in many tropical countries; the decorative Indian rubber vine has colonised large tracts of land in Queensland; the water lettuce has clogged up waterways in the Floridean Everglades.
Take the bougainvillaea (fuang faa). Although it is synonymous with Southern Europe and is a feature of gardens in many Mediterranean coastal regions, it is not always easy to grow in Spain or France. Many attempts were made in my Andalucian garden before two fuang faa became really established. Here in Phuket, the experience has been quite different. Not only are Thai bougainvillaeas available in a glorious range of colours ‒ often grafted onto the same shrub – but they grow with a vigour, nay a rapacity, that is extraordinary. They are impervious both to dry conditions and temperatures in the mid-30s.
I once had to cut down a specimen that had grown 30 feet high in a little over three years. It possessed a trunk the thickness of a man’s thigh and an armoury of long spines that rendered the whole process of removal quite painful – to me anyway… But it was painful in another way, since the shrub had been a beauty to behold, in constant flower with both white and pink bracts. A real feature of the garden. But it had to go: it was impeding the growth of other plants, was threatening to fracture the garden wall, and was beginning to spread across the narrow soi.
The pivotal point is this: Plants here not only grow far more rapidly than in Europe, they also grow much bigger. A massive generalisation, but one that is more or less true. And since most tropical plants are unfamiliar to the newly arrived expat, he does not know what to expect when he pops them into his pristine flower beds. What he might recall as a small pot plant struggling to survive in an English drawing room, can rapidly assume the proportions of a tree in this fecund climate.
Consider the so-called ‘rubber plant’, or ficus elastica. A member of the fig family and originally cultivated as the primary source of rubber, it was soon superseded by hevea brasiliensis, smuggled in from Brazil and now a feature of Southeast Asian plantations everywhere. Just look around Phuket.
On the other hand, ficus elastica never became a commercial proposition. But because it possessed such glossy, attractive foliage, and because it was tolerant of a wide range of conditions, it became a popular indoor pot plant. When I was a boy it was the first houseplant to grace our living room. And this popularity has spawned a number of attractive new varieties: nowadays, there are a number of ornamental cultivars with purple leaves or variegated or grey-green foliage. House plants all… But outdoors in the ultra-conducive conditions of Southern Thailand, it may grow to a 100 feet or more!
To a less spectacular extent, the same is true of codiaeum and the many varieties of cordyline and dracaena. Again, many of these have been lovingly grown as delicate houseplants in chilly Western drawing rooms since the early 20th century: here, dracaena fragrans is an everyday yard plant that effortlessly reaches 20 feet in height. And, what’s more, it thrives on neglect.
Unlike most of us…
Patrick Campbell’s book ‘The Tropic Gardener’, described in one Bangkok review as the best book on Thai gardening for 50 years, is available for B500 (half price) to personal callers from 59/84 Soi Saiyuan 13 in Rawai (Tel: 076-613227 or 085-7827551).