Illuminating trees is a common practice in the landscape lighting business. This is one of the first lessons taught by lighting instructors. The two basic techniques are up lighting and down lighting. Up lighting is an unnatural effect that can be rather dramatic. Our eyes are naturally drawn towards it. Down lighting is a natural effect. During the day or night, the sun and moon light pass through tree branches. Vivid shadows of the tree’s branch structure will appear on the ground. Both methods have desirable attributes.
In the initial planning stage, the professional lighting contractor who has chosen to up light a tree must first determine the position of a light source. One of the most important things to consider is the viewing angle. Trees are planted in various places on a property. Single and multiple viewing angles can be determined by walking the property. As we all know, trees come in many different colors and sizes. It will be necessary to choose the correct wattage, kelvin temperature and beam angle in order to complete the task. Naturally, trees are evergreen or deciduous. This is important to know. Deciduous trees will lose their foliage in certain seasons of the year. Illuminating these trees properly, will provide different effects in the summer and winter months. Trees normally are illuminated with at least two projection light sources. These light sources may be mounted in a directional or subsurface fixture. Mounting up lights inside a tree is also acceptable.
Items to consider if choosing to use down lighting will vary. Directional fixtures with projection lamps will provide dramatic shadows when penetrating through the branch structure. Fixtures mounted higher will require narrow beam angle lamps. Lower mounted fixtures will require wider beam angles. Filters and proper shielding will need to be addressed when using these fixtures. This will assist eliminating any potential glare. Hanging fixtures such as perforated lanterns are meant to be seen. Higher quantities and lower wattage omni-directional lamps may be required when designing with these fixtures. When installing a fixture to a tree trunk or branch, be sure to use the proper hardware. Use flanges or junction boxes specific to tree mounting. Create a “drip loop” to avoid any water intrusion into the fixture. Secure the cable with the approved hardware. Leave plenty of slack for growth. Avoid tight staples when mounting cable; these can potentially cause a short or a fire.
Take some time and educate yourself on tree variety and growth. Is it prone to branch loss due to season or storm? Will it require a higher wattage lamp in the future? When in doubt, seek the advice of a certified arborist.
