Candles are used extensively in traditional ceremonies for their excellent symbolism. Usually they have been associated in religious institutional settings. For example, the Unity Candle is a common ritual in the Catholic Church. The use of candles in a non-church venue deserves careful thought because you are playing with fire. There are safety, symbolic and practical issues to deal with.
In the Unity Candle ceremony there are three candles; two small taper ones to symbolize who you are today and one central one to light symbolizing your union. You will need to decide first-off what you will do about the small taper candles. You need to determine when they will be lit and by whom. I’ve had the couples light them as so as the bride arrived at the front; I’ve had the mothers or grandmothers light them at the beginning of the ceremony; or I’ve seen the groom light them prior to the start so that they are lit when we begin.
Once you have lit the central candle, what will you do about the two small taper candles? Will they stay lit or will you blow them out. By staying lit, then you are acknowledging that even though you are a union, you are still individuals. In blowing them out, you are saying that you are totally dedicating everything to your union. I’ve seen on more than one occasion, couples light the central candle by joining their taper candles, only to have the tapers fall out of the holders, splatter hot wax everywhere and almost catching the wedding dress on fire.
In an outdoor venue, you have the wind to contend with. This will make lighting them and having them stay lit a challenge. Furthermore in daylight, you can’t even see if the candles are lit or not. Some people try putting the central candle in a container with high walls to protect it from the wind. They light it with special wedding BBQ lighters so as to not contend with the small taper candles. These BBQ lighters can be really hard to handle. There is a security button and the trigger that must be depressed at the same time for them to produce a flame. This requires some hand strength and coordination. I’ve had to help poor grandma do this many times. My advice is to skip using candles in any outdoor wedding.