Down Lighting, Moon Lighting Do's and Don'ts

Here are the down lighting do’s and don’ts to know

Down lighting is one of my favorite lighting techniques.  I love creating a beautiful and soft full moon effect in the landscapes of the Austin and central Texas area.  We have a lot of spectacular live oak trees which really lend themselves well for this lighting effect.  So, what are some of the Do’s and Don’ts of down lighting?

DO install the lighting fixtures at least 20’ and preferably 30’ up into the tree.  Placing the fixtures this high in the canopy keeps them well out of the line of sight for those moving around the area below.  It also allows the light to filter through many additional branches and limbs to create a stunning and more natural moon lighting effect.

DON’T use a ‘too bright’ light source.  I see a lot of people using 100-watt mercury vapor lights in trees and calling it “moonlighting”.  Natural moonlight is only .01 foot candles, and it has 4000K color temperature.  A 100-watt mercury vapor light will put 2-3 foot candles on the ground or more, depending on how high the fixture is; and the color is usually closer to 5600K – much brighter and bluer in tint and looks nothing like natural moonlight.  We use 4 or 6 watt LED lamps with 4000K color temperature to more closely match the color of NATURAL moonlight.

Properly Mounted Down Lighting Fixture

Properly Mounted Down Lighting Fixture

DO use stand-off hanger bolts to attach down lighting fixtures to trees.  Attaching mounting brackets directly to a tree will cause many problems.  As the tree grows, it will grow around and eventually consume things that are attached to the trunk.  This means that the mounting bracket will eventually end up IN the tree, not on the tree.  Beetles and other insects will also crawl under that bracket and damage the tree.

DON’T staple wire to the tree!  Ever!  There are some out there who use wire staples to attach the wire down the tree trunk because it’s the fast way to do it.  The first problem is that some of the metals used in those staples can poison the tree.  The holes created in the tree if the staple falls out will become the home of destructive bugs that will damage the tree.  There is also the critical fact that the staples holding the wire (if it doesn’t fall out) will get swallowed up by the tree as it grows.  It consumes the staple and wire, damaging the entire lighting system as it pinches the wire causing short circuits.  This results in a very expensive service call when we end up having to cut the wire off to make the repairs.  We can’t dig the staple out because it can damage the tree even more than the consumption of the staple and wire. This just makes me crazy!  We use only stainless steel screws and zip ties that will break away as the tree grows. We love trees and simply hate seeing them mistreated by installers who care more about a quick paycheck than the beauty of the environment they work in.


The Right Way To Attach Wire To A Tree, With Stainless Steel Screw

The Right Way To Attach Wire To A Tree, With Stainless Steel Screw

DO get regular maintenance for down lighting to ensure the safety of the tree and the best operation of the lighting system.

I hope these Do’s and Don’ts help you to know and understand what to look for when dealing with down lighting installations.  If you do see these don’ts on your property, please let us come fix it for you.  Contact us here.

12 thoughts on “Down Lighting, Moon Lighting Do's and Don'ts
  1. Great tips here. Many people that do at home lighting installation will find this information useful!

  2. Paul: Unfortunately moonlighting with Mercury Vapor lights is a thing of the past due to its inefficiency. Do you have any suggestions with LED’s that come close to the affect that MV’s create? When we use LED’s filtered green or blue with a wide 30 -45 degree beam, it still appears like a spot light not a soft light.

    • Hello Jame, I’m sorry that I am just now seeing this. There are now lots of options to recreate the MV look using LED products. A lot depends on whether you want to use line voltage or low voltage. The big trick is to use an extremely wide beam and maybe even a frosted lens.

  3. Good info here. I was wondering where the best place to find a 4 or 6 watt 4000k bulb would be. When I search the Internet many options for other bulbs come up.

  4. Hi can you recommend which fixtures to use – manufacturer hood – I’m not in Texas so appreciate your help… Also

    • Hello Elizabeth. Please use the contact us form to email me. I will then respond. I do not want to appear to endorse any products in this thread, on my blog. Thank you.

  5. I would appreciate knowing the brand of the downlight fixture shown ib this article.

    Thanks, Steve Miley

  6. Can I use 16/2 wire for 4 lamps @ 7 watts each. Or would 14/2 be better. Longest run is 75 ft. Im splitting off that run to three other trees with separate runs of about 50 ft each..

    • The answer is dependent on your transformer’s secondary (low voltage side) protection. Most 300 watt landscape lighting transformers have a 25 amp circuit breaker or fuse which means you MUST use 12/2 wire or larger which is rated to 25 amps. 14/2 is only rated to 15 amps so if for some reason like a short circuit or a cut wire that bleeds into the ground, the load exceeds 15 amps but is lower than 25 amps, the breaker or fuse would not trip. In that case, the wire would burn up, possibly causing a fire. Now if you only have a 100 watt transformer, the secondary protection would only be an 8 amp protection so you would be ok in using 14/2 wire which gives you wiggle room while also helping you battle the forces of voltage drop. I never recommend coming out of a regular magnetic low voltage transformer with 16/2 wire. Remember the rule: size the wire to the protection device, not the load. This way, if you put too much load on the wire and the wire is sized properly, the protection device will kick in and protect the system till you get that load down to what it should be. Now having said all that, Kichler lighting has recently introduced a low voltage landscape lighting DC controller with 7 amp secondary protection which allows you to use 16/2 wire. So, check the secondary protection on your transformer to find out the rating and size your wire accordingly and I hope you have a great looking and SAFE outdoor lighting system.

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