When I planned my first Thai garden 18 years ago, I little dreamed just how fast plants would grow in such a fructuous environment. In both my London and Spanish plots, flowering shrubs had matured slowly, and pruning was rarely needed; here in Phuket, not only was I soon out buying double-handed shears to cut away the riot of thicker branches, but within a decade had to dispose entirely of a number of splendid trees. The lesson? Unless you have a seriously large plot, or need quick shade for tender understory plants, avoid planting fast growing trees.
So inevitably down and out went my champaca, avocado, traveller and Norfolk Island palms, my neem and crape myrtles. And while I hung on to large, floriferous shrubs such as oleander, tecoma stans [yellow bells] bougainvillea, and climbers such as Rangoon creeper, Bengal vine, allamanda ,and passion flower, they all needed, and still need, to be regularly kept in check.
By the way, there is an art to pruning. Remove spindly, diseased or overlapping branches first, cut the stems on the slant above a bud or growing point, and if you are trimming or thinning an entire tree or shrub, prune to retain or even improve the overall shape. For instance, never hack the crown out of a tree; it will respond by growing lots of bushy, unsightly twigs. Remember too that those woody cuttings, planted in decent soil, treated with hormone rooting powder and kept moist and shaded, may find a second existence as new stock.
Talking of soil, Phuket is not well endowed with the stuff. At best, the top soil – a richly organic medium which contains almost all the nutrients demanded by your plants, is only a few inches deep on the island. Have a look at any new excavation, and you will see exposed only a narrow stratum of dark soil. The building process compounds the problem; that foot or so of topsoil is inevitably scraped away or polluted by construction. What remains? Subsoil compounded of sand and clay which looks nice, but which is both sterile and poorly aerated. Over the years, the most repeated question from readers has been, “Where can I get some decent topsoil?” My answer: Cross his palm with silver and beg a load from the foreman of a building site.
Failing that initiative, mix bags of the fibrous stuff you buy in white sacks with your existing soil; the result will be a more friable, and better draining mixture. Using organic fertilizer or your own compost as an amendment is even better: it has the advantage of being richer in the key nutrients of nitrogen, potassium and phosphate. These amendments work in two ways: added to clay, they lighten the mixture, add porosity and improve drainage. In sandy soils they add bulk and improve water retention. Talking of nutrients, you can, of course, buy chemical fertilizer in the form of blue, green or white granules. A 16-16-16 formula is suitable for most plants. But if you want more flowers, go for a lower first number – say 1-34-32. Sprinkle sparingly and preferably before rain. Liquid foods are great but pricey. Incidentally, I will let you into a secret. Bags of topsoil and a wide range of fertilizer as well as hard-to-come-by rooting powder and humus in the form of worm castings, are available from the government store on Chao Fa East Rd opposite Dowroong Wittaya School.
If you are an apartment dweller with a patio or balcony, you are likely the proud possessor of plants in containers. And you will probably know from experience that glazed receptacles are best. Terracotta clay pots look attractive, but their porosity means that evaporation is a constant problem. Glazed pots in shades of blue or green are especially attractive, but they are expensive. I like those that have a matt brown glaze: they are available at most garden centres, and come in a range of sizes. Rectangular concrete containers are a viable alternative, but are heavy and discolour quickly. In any event, always place a saucer under your pot; it will prevent staining and will hold water in dry conditions. I prefer plastic platens: they allow you to slide heavy containers around concrete or sand-wash surfaces.And you will probably need to reposition your pots from time to time.
Clearly, your choice of plant will be largely determined by your site. If you have a sunny balcony, consider sun lovers such as desert roses [adenium] bougainvilleas, crown of thorns [euphorbia], super-hardy ixoras. Partial or chequered shade will probably mean some foliage plants, such as sansevieria [the toughest variety I know], graptophyllum [caricature plant] or codiaeum. Costus or jatropha will both add a splash of continuous colour. In full shade, try caladium, zamioculcas, dieffenbachia or aglaonema.
A herb garden is a great idea, especially if you like cooking, but begin with easy-to-grow species such as basil, mint, chili and cumin. And try a climber or two if you have a balustrade or parapet. At the other end of the scale, avoid shrubs or small trees that have taproots; a pot is too constraining for these most vigorous of growers. And remember that each and every one of l your potted charges will need more TLC ‒ more watering and more fertilizer than plants in open ground. Just don’t overindulge the watering can. Over to you, Claude…
The information in this article and much more is to be found in my book ‘The Tropic Gardener’. Described in one Bangkok review as the best book on Thai gardening for 50 years, it is available for B500 (half price) to personal callers from 59/84 Soi Saiyuan 13 in Rawai (Tel: 076-61227 or 085-7827551).