DIY Mason Jar Citronella candles GREAT IDEA!! FOR BACKYARD FUN, NO BUGS!! All you need is a package of Mason jars, some cotton string and some liquid citronella (find it in big jugs at any home-improvement store and even some grocery stores). Use a hammer and nail to poke a hole in the top of the lid, then pour in the citronella, put the top on and drop in the wick. Allow the string about 10 minutes to soak up some oil, then place them around your backyard and light them!