Living with Plants in Singapore
If you live in an apartment or a house that has 'sun-block' around you,
and don't have sufficient light for full sun plants, get indoor plants with lower light requirements...
unless you are ready to rig up 2000 watt LED grow lights.
Even with indoor plants, you can't put them in the middle of your living room
and expect them to thrive, since the middle of any room isn't usually well-lit enough for healthy plant growth.
Simply Put
Plants convert light, oxygen and water into energy to survive, grow, produce flowers, fruits and seeds.
Without sufficient light to make enough energy, plants will tap on their energy reserves, and when that is all used up, they die.
Sunlight in Singapore
Singapore lies close to the equator, so advise on websites catering to the Northern (USA) or Southern (Australia) hemispheres
telling you which window to place a plant, may not be entirely applicable to Singapore.
Contrary to popular belief, the sun does not rise precisely East and set exactly West all year round.
The sun 'shuffles slightly left and right' throughout the year.
Observant plant-enthusiasts will tell you that...
East and West-facing windows get varying hours of direct sunlight all year round.
East-facing windows get the morning sun that gradually intensifies till noon, when the West-facing windows pick up the sun which eases up as it sets.
North-facing windows get some direct rays of sun May / Jun - Oct / Nov.*
South-facing windows get some direct rays of sun Nov / Dec - Apr / May.*
*Months of direct sunlight depend on how many degrees East or West window faces.
Healthy Plant Light Requirements
High Light Plants - At least 6 hours of direct sunlight
or 10,000 - 20,000 Lux Bright Indirect Light through East or West-facing windows:
Flowering & Fruiting plants · Vegetables & Herbs · Most Cacti, Succulents & Orchids ·
Ornamental plants like the Bougainvillea, Croton, Jade Plant Crassula argentea, Hoya carnosa, Podocarpus macrophylla ‘Maki’, African Violet,
and Christmas Cactus.
Medium Light Plants - 4 hours of direct sunlight or between 2,000 - 10,000 Lux Bright Indirect Light through North or South windows: Rex Begonia, Caladium, Peacock Plant,
Spider Plant, Areca Palm, Cordyline Ti Plant, Dumbcane, Dracaena, Crown-of-Thorns, Fiddle-Leaf Fig,
Rubber Plant, Nerve or Prayer Plant, Monstera deliciosa, Tricolor Bromeliad, Boston / Staghorn / Pteris Fern,
Peperomia, Philodendron, Peace Lily, and Syngonium.
Low Light Plants - 500 - 2,000 Lux Low Indirect Light, from any window, even filtered through frosted East & West windows:
Aglaonema commutatum / crispum / simplex, Birds-nest Fern, Cast-iron Plant Aspidistra elatior,
Bamboo Palm, Parlor Palm, Corn Plant Dracaena fragrans ‘Massangeana’, Pleomile Dracaena reflexa,
Heart-leaf Philodendron, Snake Plant Sansevieria trifasciata ‘Laurentii’,
Birdsnest Sansevieria ‘Hahnii’, Asia Umbrella Tree Brassaia arboricola, and Pothos Money Plant.
Acclimatisation: Survive vs Thrive
Certain plants can be 'trained' to tolerate lower light levels, but bear in mind,
they do not prefer it, they can just 'tahan' and deal with it. They won't grow too vigorously,
but then again, perhaps that is preferable, unless you are trying to grow a jungle.
While most plants can survive in lighting 10 times lower than required,
they will not thrive. A Bougainvillea can technically survive in front
of a North-facing window, but it will not grow, flower or look anything close to a healthy Bougainvillea.
Light Intensity vs No. of Hours
Many Medium Light Plants actually do better under longer hours of bright light than directly under the
scorching rays of Singapore's equatorial sun, especially those with delicate leaves.
However, most High Light Plants will not grow to their full potential even with 24 hours of light, if the light does not reach their desired Light Intensity.
Low Light Plants like the Snake Plant or Zanzibar Gem can literally be
left in the dimmest corridor of your house with little light of low intensity and they will not die, but don't expect any growth or vitality either. Incidentally, the Snake Plant is also known as Mother-in-Law's Tongue - long, sharp, and can't be killed.
Importance of Darkness
Plants generally need 6 - 8 hours of darkness to convert the energy
they made during the day into carbohydrates, which can be stored and accessed later.
However, since this process does not require absolute darkness,
some exceptions like the Coleus, Monstera deliciosa, and Dieffenbachia (Dumbcane)
do well under light 24 hours a day.
Some Orchid and Cactus varieties will even bloom more quickly.
'Divas' like the African Violet, Poinsettia, Kalanchoe, and Christmas cactus
will not flower unless they get sufficient hours of absolute darkness - you can't even turn your TV on!
Spider plants, on the other hand, are perfectly suited for Singapore's 12-hours light and 12-hours dark cycle.
Light Intensity in Your Space
Simplest Test: Direct sunlight casts a sharp clear shadow, while indirect light casts a blurry one.
Easy Accurate Test: Measure with your phone using
the free "Lux Light Meter Free by Doggo Apps" or "Lux Meter (Light Meter) by My Mobile Tools Dev".
Just wave your phone around where you want to place your plant,
and you will get some interesting measurements that will explain why your African Violet isn't flowering all year
round or why your Lavender or Rosemary keeled over and died.
Bottom Line
Fit the plant to the amount of light you have, or if you really want to grow rosemary without direct sunlight,
and you're happy to provide artificial light,
be ready to jump into the abyss of Photosynthetically Active Radiation, Photosynthetic Photon Flux,
Photosynthetic Photon Flux Density and measuring your plant light requirements in micromoles per square meter per second,
just so you don't end up with purple lights or over-priced coloured LED strips.