A good rule of thumb if you are considering landscape lighting for your home is "large mature trees use line voltage and small ornamental trees use low voltage".
The pictures illustrate two properties we recently finished installing both low voltage and line voltage systems. The low voltage photograph shows Savannah Holly ornamental trees and a Japanese Maple being illuminated with low voltage LED uplighting. The large Texas Live Oak is illuminated with line voltage mercury vapor downlighting and uplighting.
When comparing the two types of systems there are numerous things to consider such as kelvin rating, beam spread, energy consumption, cost, warranty, and maintenance just to name a few. However, in over 85% of my initial consultations, the client's only desire is to have the end result look beautiful and they don't really care about technical specifications. In the end, the client's landscape will dictate the type of lighting and this basic design principle will serve you well.
Tip for low-voltage landscape lighting: Consider installing the electrical wiring in conduit. At E2 Illumination Designs this is almost always the "standard procedure". Code doesn't require contractors to put low-voltage wiring in conduit as in line-voltage systems. Landscapes (and client desires) continually change, so when the yardman digs up that shrub to plant new seasonal color your electrical wiring is protected.
Tip for line-voltage landscape lighting: Consider having an additional dedicated circuit pulled to one (or more) trees or any other necessary electrical locations. This will give you added flexibility with how you use your outdoor space. For example, you'll now have a plug location(s) for yard work, outdoor fans, holiday lighting, and party lighting.
E2 Illumination Designs is a design-build-maintain landscape lighting company based in Dallas and continually works throughout the country wherever fine outdoor lighting design is demanded. Please contact us with any questions.