I have recently pruned old Lilipili trees that were originally planted to be...

Asked January 20, 2015, 6:57 AM EST

I have recently pruned old Lilipili trees that were originally planted to be a hedge giving privacy to the backyard from the road. Am I able to do anything to control or encourage new growth, so as to make it back into a screening hedge, in place of a fence? I was wanting to encourage growth from the trunk of the tree, which is all you can see now. I'm worried that new growth will just come from the top and just look silly and nothing like a hedge that I was wanting!

Thanks,
Kassandra

Outside United States trees and shrubs horticulture

1 Response

Hi Kassandra --

Lilipili (or lilli pilli, or lilly-pilly, and more formally known as Syzygium smithii or Acmena smithii) is a pretty tough customer that can even be sheared to maintain a hedge form. This Australian native does have a natural tree or multi-trunk shrub form, but you should be able to readily encourage lower, outward growth. According to Weedbusters, a New Zealand organization dedicated to fighting invasive plants, some of the difficulty in eradicating this "pest" comes from its propensity to "coppice", that is, grow back multiple trunks from stumps:

http://weedbusters.co.nz/weed_info/detail.asp?WeedID=65

As with most shrubs that work well for hedges (be they sheared or natural form), you can direct growth by removing the growing tips of branches, especially those on top. This encourages growth at smaller branches farther down, and "wakes up" dormant buds along a trunk or branch to create new branches. Monitor the new growth and clip tips if your lilipili are trying to send up just a straight stem or two instead of "bushing out" from the remaining trunks.

Though A. smithii is tolerant of dry soils, growth will be more robust if moisture is available. You can also provide encouragement with light fertilization, though don't overdo it -- too much nitrogen and you'll produce rapid but weak development.

To maintain a full hedge, be sure to shape it through shearing or pruning to allow light to reach lower and inner branches. Too many hedges wind up as a "skin of green" but empty inside because their shape winds up wide at the top and even or narrower below. Sunlight hits the top and shades the rest, so growth is predominantly upward and thick at the top. A sheared hedge should be a bit wider at bottom than top so it can catch more sun along its sides, and all hedges should be kept thinned enough to allow some light and air circulation within.

It's always a bit nerve-wracking to do a full shrub renewal, but it's ok, the "hair" grows back! Just keep the pruners handy to provide guidance to any wayward branches and you should be able recreate your screen. Good luck!