Web Master:
Well Sygygium are a fantastic growing hedge especially as they grow thickly right down to the ground. so can you trim them to allow for other plants underneath? Yes you can. Will it help promote growth in the middle? Maybe, but the plant will always send out more growth in the locality that it has been trimmed - the cutting process literally stimulates the growth hormones in that area. Having said that, Syzygiums being such strong growers tend to respond all over when trimmed. And they do need a lot of trimming, generally at least four to five times a year, so you have to like your shears if you grow Lily Pillies. P.S. tip pruning is a sure fire way to encourage lower area growth.