Coastal redwood (Sequoia sempervirens) in New Zealand: what you're taking on
Quick answer: A coastal redwood commonly reaches 40 to 50m in New Zealand, and about 10m tall by 4m wide in its first ten years. There is no taproot, just wide shallow lateral roots, so it wants a large sheltered inland site with deep moist soil. It is the wrong tree for a small section, a dry paddock or an exposed coast.
Stand in a stand of big redwoods and the first thing you notice is the sound going out of the world. Everything is muffled. The light comes down in shafts, the ground is soft and rust-coloured, and the bark up close looks less like bark than like rope, deep fibrous cord you could sink a thumb into. The Rotorua grove was planted in 1901. Those trees were seedlings in somebody's nursery once, no different to the ones sitting on our pad.
That is the whole appeal, and it is also the whole problem. The plant on the trailer is 600mm tall and costs less than a bag of fertiliser. The organism you are agreeing to is 45m tall and will outlive the house, the fence, the drive and quite possibly the title boundary.
How big does a coastal redwood get in New Zealand?
Bigger than the label suggests, and faster.
Coastal redwood does not grow like a garden conifer. Here are the numbers, from small to large.
Around 10m tall by 4m wide at ten years.
About 8 to 9m at nine years on forestry sites.
Over 35m tall with a trunk over 650mm through at 50 years, on sheltered fertile New Zealand ground.
40 to 50m as a typical mature height in this country, with a spread of 8 to 12m.
Height growth is fastest up to about the 35th year, then keeps going at a slower rate for centuries. Over 1.2m of new growth in a year is not unusual on a good site, and that rate can hold for thirty years or more.
So the tree you plant this winter will be over the roofline inside fifteen years on decent ground. That is the number to sit with, not the 100m one.
Where does a redwood grow well down here?
Sheltered, inland, deep soil, reliable moisture. Miss any of those and you get a poor tree rather than a dead one, which is arguably worse, because you keep it.
Redwoods have no root hairs. That sounds like trivia until you follow it through: roots without hairs pull moisture out of soil inefficiently, so the species is tied to ground that stays damp, or to air that stays humid, or to rainfall that keeps arriving. It is not a drought tree. On a dry Roxburgh terrace it will sit there sulking and browning off through every hot February unless you commit to irrigating it for years.
It also dislikes wind, and it particularly dislikes salt. Scion put it plainly: coastal redwood thrives on sheltered inland sites and dislikes windy and coastal conditions. In its native range redwoods usually avoid hillsides facing the ocean altogether, and the ones nearest the exposed coast wear flat tops and dead limbs on the windward side. Anything with a clear run of salt air off the water, Riverton and the open coast either side of it, is a poor bet no matter how good the soil looks.
Cold is a smaller problem than either of those, with one exception. Established trees take frost. Young ones are the vulnerable ones, and NZFFA note that out-of-season frosts can kill young redwoods outright. Inland, on the flats where cold air pools, that first spring after planting is the risk. Te Anau and the inland Southland basins are the sort of country where I would plant a bigger grade and give it a guard rather than gamble on a small one.
Altitude matters too. Below 500m is where the species is happy.
So why is it called coastal redwood?
Because of the fog.
The natural range is a strip down the Pacific coast of California and southern Oregon, somewhere between 8 and 56km wide. What pins the species to that strip is the summer fog rolling in off the sea. Fog cuts the moisture lost off the foliage, and it drips off the canopy into the ground through the dry months. To a tree with no root hairs, that free summer water is the whole difference. The name is pointing at that band of fog.
Inside the band, the tree keeps its distance from the water anyway. Redwoods usually avoid the hillsides that face the ocean. The ones down at the mouths of canyons, where the onshore wind gets at them, carry flat tops and dead limbs along the windward side. The good stands sit on valley floors, canyon bottoms and river flats, taking the mild damp air and staying out of the weather that comes with it.
The other half of the name is doing a plainer job. Coastal redwood tells you which redwood: this one rather than giant sequoia, Sequoiadendron giganteum, which lives inland in the Sierra Nevada mountains.
So the name is describing a climate, mild and damp and sheltered. Plenty of people read it as a recommendation for a seafront site, and that is where the trouble starts.
How far from the house is far enough?
Further than most sites have. Here is what is going on underground.
A redwood has no taproot. What it has instead is a plate of large, wide-spreading lateral roots sitting relatively shallow and reaching a long way out. That plate makes the tree remarkably windfirm, and in California windthrow needs wet ground and a serious storm together before a big redwood goes over. It also means the root zone extends well past the canopy edge.
What that costs you at close quarters:
Surface roots lifting paths, paving and drive edges. This is the common complaint, well ahead of anything structural.
Competition. A shallow wide root plate under a lawn or a garden bed takes the water and the feed first.
Drains. Roots do not go hunting for a pipe, but any tree will exploit a joint that is already leaking, and a big root system near an old earthenware line is asking for a camera down it eventually.
Work on something like 15m from a building and 10m off a boundary as a good setback. If you are a landscaper putting one on a plan, get the distance agreed in writing at the drawing stage. Buying for your own place, walk the spot out with a tape before you order, and go and look at what is 15m away from that point in every direction, including up.
Who shouldn't plant one?
Plenty of people, and we sell the tree.
Anyone on a standard residential section. There is no version of this where a 45m tree suits 600 square metres.
Exposed coastal sites and anywhere the wind has a clear run at it.
Dry sites with no irrigation. Central Otago terraces, thin shingle country, anywhere the summer bakes.
Anyone planting for a 20-year outcome and expecting to remove it after. See the next section.
Anyone who wants a hedge. It clips, but you are trimming a tree that wants to be 45m tall for the rest of your life, and there are better tools for that job.
Redwood suits paddock corners, gully bottoms, river flats, large rural sections, avenue plantings on a farm drive, and shelter on a sheltered inland site. That is a real list, it is just a shorter one than the number of people who want one.
What happens when somebody tries to get rid of one?
This is the part almost nobody publishes, and it is the reason a redwood is a bigger commitment than most trees of the same size.
Cut a redwood down and it comes back. The species sprouts from the stump and root crown at any time of year, with new shoots showing within two to three weeks of the saw. Stumps are often ringed by more than a hundred sprouts. Those sprouts reach 600 to 900mm in their first year and occasionally over 1.8m, and they grow faster than a seedling would because they have an established root system underneath them.
Topping does not help either. If the crown is damaged, or the trunk is suddenly opened up to light, dormant buds fire along nearly the whole length of the stem and the trunk furs over with new foliage.
So removal means grinding or killing the stump, not just felling the tree. Price that in before you plant, not after. On a farm that coppicing habit is a feature, since it is why redwood is talked about for erosion control on lower slopes: cut it, and the root system stays alive and holding.
What does a redwood cost, and what grade should you start with?
Our own listed price is $16.50 excluding GST for a 2.5L grade plant, typically anywhere from 40-70cm tall.
New Zealand retail prices as at 4th September 2026, so you can see the shape of the market:
Leafland: P18 at 0.5 to 0.8m, $56. 25L at 1.1m, $116. 35L, $176. 45L at 2.2m, $228. 80L at 3 to 4m, $420. All excluding GST.
The Plant Company: 10L at around 1m, $136.04. 25L at around 2m, $270.40.
Forestry-grade contract-grown stock has historically been quoted at $0.80 to $2.50 a tree for 1 to 2 year old plants, but getting a quote is the best option here as it is volume dependent.
The spread between $2 and $420 is entirely about how many years of growing somebody else has already paid for.
For most jobs I would start small. Redwood is slow for the first couple of years, then accelerates hard, so a big grade buys you less of a head start than the price difference suggests. The catch is that being slow early makes weed control matter more for redwood than for most species. A small tree in long grass gets swallowed. Keep a clean circle around it for the first two summers and it will overtake the plant that went in twice the size into rough ground.
Two things will kill young ones on a rural site. Hares and rabbits slice them off near ground level at a 45 degree angle, which is a distinctive cut and a dead tree. Cattle rub the bark off young stems. Guard accordingly.
If you want the scale but not the redwood
Two natives that get properly big, both of which we grow, and neither of which will chase you around the property for the next 200 years.
Red beech, Fuscospora fusca. To around 35m. It belongs on lower hills and inland valley floors with fertile, well-drained soil, which is roughly the same brief as the redwood, so if your site suits one it will often suit the other. Slower, and that is the point.
Black beech, Fuscospora solandri. To around 27m, and it takes the drier eastern country the redwood will not. Moderately fertile, free-draining ground at lower altitude on the dry side of the ranges. This is the one for a Canterbury or inland Otago site where a redwood would need a hose for a decade.
Neither gives you the fibrous red bark or the cathedral effect. Nothing does. What they give you is a big long-lived tree that suits the ground it is standing on.
Common questions
Is coastal redwood the same thing as a giant sequoia?
No. Giant sequoia is Sequoiadendron giganteum, a different species with a fatter trunk, a stiffer conical shape and a preference for drier ground. Coastal redwood is the taller of the two and the one that wants moisture and shelter.
Can I grow redwood for timber?
Yes, and around 10,000 hectares were in the ground in New Zealand as at 2018. The heartwood is durable, light, stable and easy to work. Under the building code it is an acceptable solution for exterior cladding but not for decking or framing, and its strength and stiffness sit at about 70% of radiata of the same grade. Rotations of around 35 years are suggested, or whenever the trees hit 600mm at breast height.
Will it seed everywhere?
Unlikely. Redwood seed is heavy for its size, has no effective wing, and falls close to the parent. Most of it is not viable at all: in one study only 1 to 32% of seed was sound, the rest empty or full of tannin, and trees under 20 years old produce seed that is generally less than 1% viable. Effective seeding distance from a stand edge has been measured at about 60m uphill and 120m downhill.
Will it grow in wet Southland ground?
Not in the sodden stuff. It wants moist and free-draining, which is a narrower target than it sounds down here, where the next rainfall usually arrives before the last one has finished draining away. A river flat or a gully bottom with moving water through the profile suits it. A flat paddock that holds surface water through August does not.
Does it clip?
It will take a trim, and the 'Korbel' selection is sold specifically for hedging. But trimming a coastal redwood into a hedge is a permanent job on a plant with permanent ambitions, and I would rather sell somebody the right hedge plant than a redwood they will be fighting.
Coastal redwood is a wonderful tree on the right site and a 200-year mistake on the wrong one. The site decides it, and the site is usually already decided before anyone rings up about the plant.
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