You may have planted trees closer to your home to shade it, and yes, this will help cut down on your energy bills in the hotter months. However, you may be curious as to whether you should shade your air conditioning unit as well. After all, all that hot sun blazing down on the metal unit must make it harder to cool the air. It is only natural to think that, but the short answer is that shade for an air conditioner does more harm than good.
When the sun is blazing down on the metal of your air conditioner, the truth is that the important parts are already shaded. The metal casing protects the important parts of your air conditioner from the sun already. The heat of the outside casing makes virtually no difference towards the energy efficiency of your air conditioning unit.
One issue to consider if you do decide to shade your air conditioner is the harm that can happen. Air conditioners are designed to be pretty efficient at draining away condensation and otherwise evaporating away excess moisture from natural events like rain. Shade can prevent sunshine that makes your air conditioner do this faster. The longer that moisture lingers in your air conditioner, the more harm it can do. It is not only a worry of mold, mildew, or algae growing inside your air conditioner, but a worry of rust. All of these moisture-caused issues can be dealt with in yearly inspections, but shaded units will cause them to come back sooner and do more damage. Essentially, what you need to consider is that too much shade over an air conditioner unit has no benefits and can actually shorten the life of your air conditioning unit. It is best to actually just let the sun shine right on it to help keep the moisture under control.