Good planting schemes are like good food, often, less is more. It would be easy to go crazy and plant anything and everything - everywhere - and watch it all grow in one huge colourful explosion, that may even achieve some very pleasing results, but in essence, being a good garden designer involves being a good artist.
Experience will help you - you need to match plants with the suitability of your plot. Shade loving plants are no good in exposed tropical sun... Certain grasses won't grow in shade.... So if you have only modest experience of tropical plants, seek out a good Thai garden designer.
Your own personal tastes - Take a good look at tropical plants and trees in magazines, websites and in your own and others gardens. Tropical plants and trees all have their own quirks and characteristics - some are bright, inviting, warm, some are barely noticeable for their natural camouflage, understated, small but unique or zesty, spiky and even dangerous looking. Shape and form of your selection of individual plants wll be the foundations of your planting scheme.
The other major elements of the plot should be carefully considered - water features, walls, ponds, walkways, paths and salas - all vitally important to the design of various planting schemes and their possible layout and direction. The whole garden should come together as one composition, rather than a series of separate instalments.
If you are working with a blank canvas, treescape is your first important consideration - trees in Thailand are important - to create shade, privacy and tropical environments. Choosing the wrong trees can be a big expensive mistake. Firstly, if the wrong trees are planted too close to the homestead, within a few years the roots could undermine the foundations of buildings, walls, pools and terraces. Also, many trees drop lots of leaf litter, so you have to consider how much maintenance is acceptable for you - plus, certain trees attract unwanted wildlife. All these issues should be addressed at the initial planting stages, so if in any doubt talk to a reputable Thai garden designer before purchase and installing.
Colours obviously play a huge role in the success of a attractive tropical planting scheme - you really have thousands of different hues to play with. Remember that most tropical gardens will have a large amount of 'green,' especially so in the rainy season, so the combinations of constantly flowering shrubs, plants and trees with colour (with interesting shapes) is a important consideration.
Once you have any themes, directions and layouts factored in, you can choose your constituent plants. Don't forget, most planting schemes can benefit from garden furniture and ornaments - a half hidden Thai figurine, a wooden swing seat, an attractive accent tree - all add character and interest along with practical function. To purchase garden ornaments and artwork, discuss with a good Thai garden designer, who will have access to more sources and suppliers.
The ability to create harmonious, colourful combinations and shapes with plants and trees to make others feel relaxed, welcome, at home and inspired by nature is at the heart of good tropical planting schemes.