Privacy & Screening Plants

A screen has one job. Put something solid between where you actually sit and whatever you would rather not look at. A hedge answers a different question. It is a clipped line you maintain on a schedule. A screen can be loose, uneven and slightly wild, so long as the sightline is gone. If you want a flat green wall trimmed twice a year, this is the wrong page. Wrong page too if your bed is 400mm wide against a colorbond fence. Nothing woody here stays that narrow.

Fix the sightline before you pick the plant

Judge it from the deck, or the kitchen window, or wherever the neighbour's upstairs window bothers you. Never from the fence. The further a plant sits from you and the closer to the thing being blocked, the less of it you need. A screen set two metres inside the boundary beats the same plant jammed against the palings. It also only has to be dense from eye level up. Bare legs underneath are fine, often better, because you keep the airflow and you keep a planting bed. A hedge gets no such licence. It holds foliage to the ground or it reads as a failure.

Climate and aspect narrow the list fast

There are 189 lines here and the lilly pilly group carries the range: brush cherry and lilly pilly together make up more than thirty. Resilience brush cherry keeps a tight leaf through Brisbane humidity and runs from a 140mm pot up to a 200L bag, so one cultivar can cover a whole boundary. It wants steady moisture. On a west-facing verge with no irrigation it browns off and sheds leaf. Calcareous coastal sand and salt wind, the Perth and Adelaide beach suburbs, suit New Zealand Christmas bush: full sun, very little water once it is down. Soil that ponds after rain suits melaleucas and bottlebrushes better than anything glossy leaved, and Dawson River Weeper bottlebrush makes a soft weeping screen. A south-facing fence is the hard one. Three hours of winter sun in Melbourne pulls the full-sun natives thin and leggy, while Sweet Viburnum stays dense in part shade and moves quickly doing it.

Sizes, spacing and the two expensive mistakes

Close to two thirds of the sizes here are quoted in millimetres, which understates the gap between them. Width climbs in a straight line, volume climbs cubically. A 140mm holds roughly 1.5 litres of mix, a 200mm about 4.4, a 300mm close to 15. Stepping from a 200mm to a 300mm is not one size up. It is three times the root ball. Bigger stock buys cover on the day it lands, and that is the whole of what it buys. It often stands still a season while the roots go looking for the rest of the bed.

The first mistake is planting too close, and everyone makes it, because a tight row looks finished sooner. Two years on they are fighting each other for water, bare at the base, and when one dies you have a gap you cannot fill without lifting its neighbours. The second is choosing on speed alone. A fast screen is also the thing you are cutting off the gutter in year five, and figs in particular send roots under paving and into old clay pipes. Speed is worth having at a second-storey sightline. Along a side path it is a chore you signed up for.

For a formal clipped line in one cultivar, go to hedging plants. The lilly pilly range lists those cultivars on their own. Where the bed is too narrow for a shrub, climbing plants on wire or mesh cover a fence in a strip you measure in centimetres.