With limits on space and time, what is the best way for your outdoor space to really come alive after dark? The first rule is subtlety; too much of a good thing can overpower the beauty of the plants and landscape design, so keep it simple.
Think about colour temperature of your light sources. Lamps tend to range from 2000 Kelvin (K) to 6000K for most commercial LED or lamps. 2000K is a warm colour close to the red end of the visible light spectrum, while 6000K is cool and close to the blue end. Use those differences rather than bright colours to emphasise texture and size. Consider lamps or LEDs with a warmer colour temperature for plants with an orangey red hue to their foliage and perhaps cooler ones for those with lots of green or variegation, as this will bring out their unique characteristics.
Strong architectural plants can benefit from close inset lighting which highlights the larger leaf structure or sheer size of the foliage, giving
dramatic shadows. Small trees might look more dramatic with lighting which catches the branches rather than just the leaves. This also works well when the trees are free of leaves and at that time colour could be introduced to replace the softness that leaves bring. Lighting should not compete with the plants or trees but enhance them.
THE FIRST RULE IS SUBTLETY; TOO MUCH OF A GOOD THING CAN OVERPOWER THE BEAUTY OF THE PLANTS AND LANDSCAPE DESIGN, SO KEEP IT SIMPLE
Colour rendition (CRI/RA) will determine how true your colours are when viewed under artificial light. Daylight, for instance, has a colour rendition of 100 (the highest achievable) where as low pressure sodium lighting, which was once used in streets and has a distinctive orange colour, has a colour rendition of zero. For outdoor environments where foliage and flowers are integral to your design then a high CRI or RA is preferable. Try to ensure your lamps or LEDs are rated at 85 or above. Also try to make sure they have sufficient R9, which for LEDs can be missing, and will mean your reds won’t be well represented.
Times they are a changin’
With any design there will be elements which will hange over time, and all of a sudden you realise your light is now under the bush instead of lighting it. Other problems can be grass cutting over -ground luminaires and vandalism. Always think about the longer term implications of placement of your lights and how you will maintain them.
Finally, try to remember that the light is there to ncourage people into the space after dark and to make them feel comfortable. Lighting the outer edges of the space can make people feel safer as it improves their depth of visual field. Lighting vertical surfaces also works so that people or animals can be seen against a lit surface. Think about ambient lighting to gently wash the area so at faces can be seen and to create a homogenous space for all to enjoy.