How Far Apart Should You Plant a Hedge?

Nearly every failed hedge we are called to look at failed for one of two reasons: the plants were jammed in too tight, or they were spread too far apart and the owner gave up waiting. Spacing is the single most consequential decision in a screening job, it is made once, and it is expensive to undo. Here are the numbers that actually work.

The rule underneath all the numbers

Space at roughly one third to one half of the plant's natural mature width. A species that naturally spreads to 3m goes in at 1 to 1.5m centres. A species that spreads to 2m goes in at 700mm to 1m. That overlap is what forces the plants to knit into a single mass rather than sitting as a row of individual balls.

Two adjustments to that. If you want a tall screen rather than a clipped hedge, move towards the wider end of the range, because you are letting each plant develop more of its natural form. If you want a tight formal hedge you will clip hard twice a year, move to the tighter end.

Measure centre to centre, from the middle of one rootball to the middle of the next, not from the edge of the foliage.

Spacings by species

These assume advanced stock, which in our range means 45L or 400mm pots and larger. Plants at that size typically arrive 1.5 to 2.5m tall with 500 to 800mm of width already, so they are past the stage where extra tightness helps.

• Japanese box (Buxus microphylla var. japonica). Low formal hedge to 500mm to 1m. Space 250 to 350mm.
• Coastal rosemary (Westringia fruticosa). Hedge 1 to 1.5m. Space 600 to 800mm.
• Murraya paniculata. Hedge 2 to 3m. Space 800mm to 1m.
• Photinia 'Red Robin'. Hedge 2 to 4m. Space 800mm to 1m.
• Sasanqua camellia. Hedge 2 to 3m. Space 800mm to 1m, or 600mm if espaliered flat against a fence.
• Syzygium australe cultivars such as 'Resilience' and 'Backyard Bliss'. Screen 3 to 5m. Space 750mm to 1m for a clipped hedge, 1 to 1.2m for a looser tall screen.
• Syzygium 'Pinnacle'. Naturally narrow and upright to 4 to 5m by only 1 to 1.5m wide. Space 800mm to 1m.
• Pittosporum tenuifolium 'Silver Sheen'. Screen 4 to 5m by 1.5m. Space 700mm to 1m.
• Podocarpus elatus 'Blue Gem'. Screen 3 to 5m. Space 800mm to 1m.
• Viburnum odoratissimum. Vigorous screen 3 to 5m. Space 1 to 1.2m.
• Elaeocarpus eumundi and 'Prima Donna'. Screen 5 to 8m. Space 1.2 to 1.5m.
• Magnolia grandiflora 'Little Gem' or 'Teddy Bear'. Screen 4 to 6m. Space 1.5 to 2m. These have thick, layered foliage and look wrong crowded.
• Weeping lilly pilly (Waterhousea floribunda). Tall screen 6 to 10m. Space 1.2 to 1.5m.
• Clumping bamboo (Bambusa textilis 'Gracilis'). Screen 6 to 8m with a clump 1.5 to 2m across. Space 1 to 1.5m.

If you are still weighing species rather than spacing, our comparison of hedging plants side by side sets out growth rates, clipping frequency and the pest issues each one carries.

Why planting closer does not close a screen faster

It feels like it should. Squeeze in 40 per cent more plants and surely the gaps disappear sooner. In practice you get a hedge that closes marginally faster in year one and then works against itself for the next twenty.

Crowded roots compete for the same water and nutrients, so every plant grows more slowly than it would have. The interior of the hedge shades itself out, and the base goes bare and woody, which is exactly the fault everybody complains about. Air movement drops, so fungal problems and scale build up. And when one plant dies, the gap is harder to replace because the neighbouring root systems have already occupied the space.

The one legitimate reason to plant tighter is a short term screen you accept will need replacing, or a formal hedge below about 1m where the plants are being kept small by clipping anyway.

How far off the fence or boundary

Set the row at least half the mature width off the boundary, plus another 300 to 500mm so you can get behind it to trim, clean gutters and access the fence. In practice:

• Low hedge to 1m: 400 to 600mm off the fence.
• Screen of 2 to 3m: 800mm to 1.2m off.
• Screen of 4m and above: 1.5 to 2m off.

Planting hard against a fence looks efficient and creates two lasting problems: the back of the hedge never develops, so the plant grows lopsided towards the light, and any fence repair means cutting your screen apart. Timber fences also rot faster with permanently damp foliage against them.

Overhang across a boundary is the neighbour's legal right to cut back to the fence line, and they will. Plan the row so a mature hedge sits inside your own ground. Our guide to planting near a boundary fence covers the practicalities in more detail.

Single row or staggered double row

A single row is right for almost every domestic hedge. Modern screening cultivars are bred for density, and a properly spaced single row of advanced plants will close completely.

A staggered double row makes sense in three situations: where the bed is 1.5m or wider and you want an immediate deep visual mass; where you are screening noise or wind, and depth genuinely helps in a way that a thin row does not; and where the species is naturally open and never fully dense on its own.

For a double row, offset the rows by half the in row spacing and set them 500 to 700mm apart front to back. Understand what you are committing to: roughly double the plants, double the water demand and double the trimming, for a result that is deeper rather than taller.

Setting out on the day

Do the maths before anything is unloaded. Measure the total run, subtract the setback you want at each end, then divide by your intended spacing to get the number of plants. Round to a whole number and adjust the spacing slightly rather than squeezing an extra plant in at one end.

• Run a string line the full length so the row is dead straight. A hedge that wanders by 100mm looks wrong forever.
• Mark every position with a peg or spray paint before digging anything.
• Set the end plants at half the normal spacing in from the corner or the wall, so the hedge finishes cleanly rather than stopping abruptly.
• Dig a continuous trench rather than individual holes wherever the ground allows. It gives roots a shared run of loosened, improved soil and produces noticeably more even growth along the row.
• Call for underground service locations before excavating along a boundary. Water, gas, electrical and telecommunications lines follow fence lines more often than not.
• Plant so every rootball sits at the same finished level. A hedge planted at inconsistent depths grows at inconsistent rates and never quite evens out.

Getting the ground ready before delivery day makes a real difference to how quickly a hedge closes, and it is worth reading our site preparation guide before you order. When we supply a hedge, our crew sets out the line, digs the trench, plants the run to the spacing and mulches it as one job, which is set out on our supplied and installed page.

The first two years decide the base

Spacing determines the potential. Formative pruning determines whether you reach it. Tip prune lightly and often from the first season, taking a small amount of the growing tips across the whole plant rather than waiting for it to reach full height and then cutting it back hard.

Trim the sides so the hedge is very slightly wider at the base than at the top. A hedge clipped straight up, or worse, wider at the top, shades its own lower half and goes bare from the ground up. That slight batter is the difference between a hedge that screens at ankle height and one that only screens above 1.5m.

Water deeply along the whole trench rather than spot watering individual plants, and keep the mulch pulled back from the stems.

Where to start

Work out the height you need first, because that narrows the species list faster than anything else, then apply the spacing above. Our privacy screening collection covers the taller trees and screens for blocking a two storey outlook, and shrubs for privacy covers the 2 to 4m range that suits most fence line hedges. If speed is the deciding factor, see our guide to the best fast growing screening plants.

Measure the run, pick the species, divide by the spacing above, and set the row far enough off the fence that you can walk behind it. Send us the length and the height you need and we will confirm the plant count before you commit to anything.