Tree of the moment: Cockscomb

In a front corner of the Botanic Park site in Brookfield, Tauranga is a magnificent cockscomb or cockspur coral tree (Erythrina crista-galli) planted by the late Frank Sydenham who has gifted his 3ha to the city. Oddly, this tree isn’t on Tauranga City Council’s lists of heritage trees or protected trees, or maybe it’s not so strange given that both lists are surprisingly small for a city of 110,000 people!

I noticed the Botanic Park coral tree on the way back from photographing a much smaller tree hanging over a garden fence in the Cherrywood area. Still, the photos will give you the idea (I hope) that a really big tree would look striking.

Photo: Sandra Simpson

As you can possibly see from the flower, coral trees are members of the legume family and are native to the world’s tropical belt – there are many, many varieties.

Stirling Macoboy, in his What Tree is That? book published in 1979, says the wood is brittle “and useless for woodworking”. He also advises that E. crista-galli needs annual pruning back to the main trunk in its younger years, which seems to be what the garden owner has done.

Photo: Sandra Simpson

Macoboy notes that the trees enjoy a climate on “the warm, dry side but seem indifferent to winter cold short of frost”. Tauranga ticks two of those boxes but couldn’t be classed as a dry area.

E. crista-galli, planted as street trees in California, are native to Argentina, Uruguay, Paraguay and southern Brazil (and is the national flower of the first two).

But not all coral trees are summer flowering – Erythrina speciosa is a winter-flowering tree that blooms on bare branches.

Seen in a Mt Maunganui reserve in September – the tui were enjoying it too. Photo: Sandra Simpson

Read a great article about many different Erythrina trees here.


Out for a walk this morning and I paused for a moment to admire a bank of blue and white agapanthus flowers. A bit guiltily, I might add, as we’re all supposed to be wary of agapanthus after Weedbusters and the Auckland Regional Council declared the southern Africa native a threat to our native bush, although it’s still to appear on the National Plant Pest Accord.

It escaped inclusion in the 2011/12 updated list but the trade off was a banning of sales in the Auckland region of agapanthus types that grow over 50cm tall.


A bank of miniature agapanthus at Te Puna Quarry Park. Photo: Sandra Simpson

But agapanthus have plenty of fans too. Their fibrous root systems are great for holding banks together, the plants are drought tolerant and can be used to give a tropical look to a garden, they have reliable, showy flowers over a long period and will grow in full sun or heavy shade, and are a sure bet for coastal gardens … but they can quickly grow into large, difficult-to-remove clumps (stock will eat the leaves down to the ground, but the tubers are likely poisonous) and should be dead-headed to prevent seeding.

So, a six and two-threes situation.


Agapanthus Thunder Storm bred by Ian Duncalf. Photo: Courtesy Ian Duncalf

However, plant breeders are coming to the rescue with sterile and low-fertility forms. Renowned Australian plantsman Anthony Tesselaar waxes lyrical about his company’s Storm series of agapanthus, which includes the variegated – and sterile – Thunder Storm bred by Ian Duncalf of Te Puna, near Tauranga.

There has been some research done into sterile and low-fertility forms, including at Landcare Research (the information is undated on the link, but is from 2012) and at Auckland Regional Botanic Gardens (the trial to find “ecopanthus” continues there this summer), which is where Agapanthus Seafoam originated.



Agapanthus Finn, a sterile dwarf agapanthus bred by Ian Duncalf and named after his youngest son. Photo: Sandra Simpson

Non-invasive agapanthus bred by Terry Hatch of Joy Plants in Auckland include Pavlova, Baby Pete and Sarah.

The Royal New Zealand Institute of Horticulture in 2012 published an illustrated article on agapanthus in this country (pdf).

Meri Kirihimete to readers near & far

  • The natural range of pohutukawa is from New Plymouth and Gisborne north.
  • The trees that grow around lakes Rotoiti, Tarawera and Okataina  in the central North Island are the only natural inland populations.
  • The largest pohutukawa forest in the world is on Rangitoto Island.
  • The oldest and largest tree in the Tauranga area is at the Pitau Rd reserve in Mount Maunganui, believed to be 400 to 500 years old.
  • The variety Metrosideros excelsa Mt Maunganui are all cutting-grown descendants of this tree.

Nothing says Christmas in New Zealand like our very own Christmas tree decorated in red and green – and in 2014, thanks perhaps to our cold, extended spring, many will be at peak blooming for Christmas Day.

The pohutukawa (po-hoot-oo-car-wah) is part of the Metrosideros family that includes 12 species native to New Zealand, most of them rata (a name applied to vines, shrubs and trees). There are also Metrosideros native to the Pacific islands, including New Caledonia, Samoa, Fiji and the Kermadec Islands.

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Nothing says summer more than pohutukawa in flower at the beach. Photo: Sandra Simpson

Metrosideros excelsa is the most common tree in New Zealand and is a vigorous plant with tenacious seedlings that will even grow in cracks in concrete. It’s also popular in parts of South Africa but is now regarded as an invasive species, while street plantings in San Francisco ended up causing expensive damage to pavements and pipes.

There are many forms of M. excelsa available, including Aurea (note that the date of discovery quoted in the link is more likely to be 1940, not 1840) and Moon Maiden (both with yellow-ish flowers), Gala (variegated leaves), Pink Lady (pink flowers), Octopussy (weeping habit), Maori Princess (dark red flowers, often single trunked and all descended from a single tree in New Plymouth), and Vibrance (bright red flowers, often single trunked with a spreading canopy).

Here in Tauranga, the City Council uses big trees in reserves (M. excelsa, for instance, can grow to 20m high and 20m wide) and smaller varieties on streets and verges with the slower-growing “compact” Scarlet Pimpernel preferred for under power lines.


Metrosideros Maori Princess is used as a street tree in parts of Tauranga. Photo: Sandra Simpson

Lighthouse is a variety from the lava flows of Rangitoto Island in Auckland’s Hauraki Gulf and is another “compact, erect” tree to 5m, while Mistral is a natural hybrid of M. excelsa and the northern rata, Metrosideros robusta, discovered on Great Barrier Island and described as slow-growing to 4m.

Maungapiko is a cross between M. excelsa and southern rata, Metrosideros umbellata, and is described as slow-growing to 5m.

If you hanker after pohutukawa flowers but not the size of the tree, you could try the small, shrub-like Tahiti which flowers from winter into spring, or Spring Fire (based on a plant native to Hawaii) that flowers from spring into summer.

Generally, though, pohutukawa from other places tend to flower off and on throughout the year rather than putting on a massed display in summer.


Some pohutukawa grow red-tinged aerial roots. This is the oldest tree in the Tauranga area, dating to pre-European times. The multi-trunked tree can be found in Pitau Road, Mt Maunganui. Photo: Sandra Simpson

Although pohutukawa have now been planted widely throughout the country by Project Crimson, southern rata may be a better bet for readers further south in New Zealand.

Read a Sandra’s Garden story about specialist Tauranga area growers, Pohutukawas a Plenty.

Flash sale!!

For anyone who is a registered “follower” of this blog – as a thanks to you for your support over the year – my calendar will be $NZ10 plus P&P (and as an extra deal for followers in New Zealand, I’ll make the postage up to Fastpost).

Price details and a sample image in the post below.

Email me or phone 07 577 6676 to place an order.

(If you sign up as a follower now, you can also get the discount. Just hit the “follow” button on the top of the screen and I’ll receive an alert with your details.)

On the road: Riverstone Kitchen

Riverstone Kitchen is open from Thursday to Monday and is sited a few kilometres north of Oamaru on the landward side of State Highway 1. For more information phone 03 431 3505 or see the website

Riverstone Kitchen and its chef-owner Bevan Smith have quickly gained a rock-solid reputation – and for gardeners a visit to the restaurant just north of Oamaru on the east coast in the South Island is a double delight, thanks to its beautiful, productive gardens.


Cabbages, silverbeet, fruit trees and herbs grow in among the flowers. In the background is a chook run. Photo: Sandra Simpson

Head gardener Leigh Steel is a florist by training but was brought up in a family of female vege growers so was happy to take on a role at Riverstone when asked.

“People get quite overwhelmed by the size of it but it’s just the same as a home garden – only on a larger scale.”

Bevan, who has written two cookbooks about seasonal eating (his pink-haired mum Dot Smith has this year published a book about the castle she’s building near the restaurant), says the garden provides all the restaurant’s herbs and leafy greens and about 50 per cent of the rest of the produce used in-house, mainly specialist crops like Florence fennel bulbs, Jerusalem artichokes, purple-spouting broccoli and celeriac.

However celeriac, a root vegetable, is something of a bete noir for Leigh. “It can be temperamental,” she says, “and can run to seed quite easily – one year I lost the whole lot. It needs good compost and plenty of water. Like garlic, it’s a six-month crop so it’s lovely to get it into the restaurant.”


The lidded pots are rhubarb forcers, sold on site at the store run by Bevan’s mum, Dot. Photo: Sandra Simpson

The North Otago soil is stony and free-draining so Leigh lays straw mulch in summer to help retain moisture. “At the height of summer a lot of my job is watering,” she says.

Flowers, some edible, help attract pollinators and beneficial insects and beehives are put in the orchard in spring to ensure good pollination.


Oyster and mussel shells from the kitchen are re-used on garden paths. Photo: Sandra Simpson

The garden is as organic as possible and waste plants go to the free-range chickens which, in turn, supply eggs for the kitchen, while mussel and oyster shells are reused for paths. Compost is made off-site.

Microgreens are grown year round with each crop cut twice, while cavolo nero (Italian black cabbage) can be picked for eight months “if you’re careful”, Leigh says.


A harvest in waiting – blackberries. Photo: Sandra Simpson

Most produce, including fruit, is used fresh but the kitchen also makes jams, jellies, chutneys and elderflower cordial.

Cherries are grown in a netted enclosure to prevent bird damage but on December 17 last year the area was hit by a hailstorm and wiped out the crop.

“Gardening can be a tough old thing,” Leigh says “but we don’t let it get to us.”


The woven willow hedge has been created by Mike Lilian, a Kakanui craftsman. The trunks will fuse as they age but the plaiting will remain visible. Photo: Sandra Simpson

Visit the website of Mike Lilian.

Rose trial winners 2014

Hayden Foulds of the New Zealand Rose Society has sent news of the winners from the national trial grounds in Palmerston North, announced last week.


Winner of the 2014 Gold Star of the South Pacific, Christchurch Remembers bred by Rob Somerfield. Photo: Hayden Foulds

The Gold Star of the South Pacific, the top prize from the trials, went to a red rose named to commemorate the Christchurch earthquakes, Christchurch Remembers, and is from the increasingly successful stable of Rob Somerfield (Glenavon Roses) from Te Puna, near Tauranga.

“The name had to go to a red rose,” Rob says. He hopes a bed of the rose will form part of the official memorial once plans are finalised. The rose will be released to the New Zealand market in 2016 or 2017.

Rob also received two Certificates of Merit for the pale pink Eye Candy and the tangerine-orange Hot Topic, also due for commercial release in 2016 or 2017.


Christophe, bred by Colin Dickson, won a Certificate of Merit. Photo: Hayden Foulds

The other Certificate of Merit was presented to the vibrant orange Christophe, bred by Colin Dickson of Northern Ireland and entered by Matthews Nurseries in Wanganui.

Rob has now won five Gold Stars now with only the legendary Sam McGredy in front, although Hayden points out that Sam won most of his in the era when two or even three were awarded each year, rather than just one as has been the case for the last 20 years.

Rob’s Gold Star winners are: Star Quality (2004);  Pacific Glory (2006); Sunline (2007); Love Heart (2009); Christchurch Remembers (2014).

The New Zealand Rose Society trials are now into their 44th year within the Dugald Mackenzie Rose Gardens in Palmerston North. The trials test new varieties from New Zealand and international rose breeders and are assessed over two years by a panel of 20 judges. They mark for things such as freedom of flowering, health, plant quality, flower quality and fragrance.

At the conclusion of each trial, those roses which have gained an average of 70% are recognised with awards and reflect the consistently high performance that they have achieved during trial.

On the road: Trott’s Garden

Trott’s Garden:

Where: 371 Racecourse Rd, Ashburton (off SH1).
Open: September to May, Monday to Saturday, 9am-4pm.
Cost: $10 per adult.
More information: Phone 03 308 9530 or see the website

This time last year I was in the South Island attending the Young Scientist’s graduation in Dunedin – and finally realising my dream to detour slightly off State Highway 1 and find the Trott garden in Ashburton as we headed back to the airport in Christchurch. It’s one of the best private gardens in the country and adheres to a sign in the entry – a garden is not an object but a process. Read on …


Photo: Alan Trott

Alan Trott always wanted a big garden, so although it takes several hours to mow the lawns, he’s not complaining.

The 2.8ha Trott’s Garden, on the outskirts of Ashburton in Canterbury, has been judged a garden of national significance, applauded for its spacious layout, thoughtful plantings and impeccable knot gardens.

German author Kristin Lammerting, who spends part of her year in New Zealand (she’s co-owner of Palmco in Kerikeri), has described the carefully laid out and clipped box patterns in a book as the “most sensational” and largest knot gardens in the world. The smaller garden includes a viewing platform so the patterns may be appreciated, and in the other direction also overlooks the hosta area.


The smaller knot garden. Photo: Sandra Simpson


The main knot garden. The 1916 chapel in the background was moved from Ashburton in two pieces in 1990 and is used for weddings and events.Photo: Alan Trott

“They’re true knot gardens,” Alan says, “not a parterre which is simply a geometric shape. Our hedges form knots.”

He and wife Catherine bought the property in 1978 and Alan set about designing a pond, a woodland area and a 110m-long double herbaceous border, opening to the public in 1984 after many requests.


Part of the long border. The flowering plant in the foreground is Persicaria mollis. Photo: Sandra Simpson

“I’m completely self-taught,” Alan says. “You can’t learn by reading books, you have to do it. People said it would be too exposed for a garden because there was no shelter. I can listen to advice but I don’t have to take it.”

He worked in an office for 22 years before “going through menopause” and throwing in his job to became a fulltime gardener. “I’d had a gutsful,” he says of the office job. “so I took a gamble and made the garden my job.”


Euphorbia Dixter. Photo: Sandra Simpson

“I don’t dwell on the past – you’ve always got to be thinking of new ideas and new plants,” Alan says of his garden. “If something doesn’t perform, it comes out. I’m keen on the new perennials so I’m running out of room. I’m also getting a lot of new dahlias from Keith Hammett in Auckland for the red garden.”


A view of a portion of the red border. Photo: Sandra Simpson

He added a 65m long and 5m wide red garden in 2005, a bed that provided inspiration for a 2009 Ellerslie Flower Show in Christchurch, with the ‘I See Red’ team of Alan, Sir Miles Warren, Pauline Trengrove and Marilyn McRae winning gold.

Plants used in the red garden include Malus Samba with its plum-size fruit, red or purple Oriental lilies, dahlias and poppies, purple amaranthus, purple-leaved maples, Berberis Little Favourite as an edging and spires of Berberis Helmond Pillar. Sure, the garden’s not exactly red – and how hard on the eyes would that be? – but it is an exciting use of plant textures and colours on the red-purple (and orange-brown to a lesser extent) spectrum.


Photo: Alan Trott

Alan’s eye for detail throughout the garden, which also includes a pond and a silver birch lawn, is extraordinary, making this a garden well worth a small detour.

Most of this article was originally published in the Bay of Plenty Times and appears here with permission.