The pros and cons of the campanulata cherries

Manna from heaven for the tui

Manna from heaven for the tui

Taiwanese cherries, Fomosan cherries, Prunus campanulata – they are one and the same and around this time of the year are explosions of candy pink which bring tui to the garden. In our case, it is not one or two tui. We could count them by the score if they would just sit still long enough for us to carry out a census.

Mark was not too sure about the tui which seems to have mastered the sound of vuvuzela. But I digress.

Love the trees or hate them, the tui have no qualms at all. The nectar is manna from heaven to them. And therein lies the problem. I was contacted recently by someone who is crusading against the sale and planting of campanulata cherries and I was only relatively sympathetic because I think we are in danger of throwing out the baby with the bathwater.

The problem is the seeding habits of some campanulatas. Many set prodigious amounts of seed which is then spread far and wide by our bird population. There is an alarmingly high rate of germination. The seedlings grow rapidly and after the second season, plants are too big to hand pull out. If you cut them off, they grow again. So bad is the problem that they have been banned in Northland and this correspondent would like to see them banned everywhere.

“There are loads of better trees for Tui such as Kowhai, Rewarewa that can be available at the same time” he claimed. I don’t want to be picky with someone who genuinely cares for the environment, but on a property packed with food for the birds, I have never seen a plant as attractive to tui as the campanulata cherries. Besides, in late winter, neither kowhai nor rewarewa are in flower yet.

I mentioned babies and bathwater because the problem is seeding. There are sterile forms of campanulata and both gardeners and tui alike may rue the day if ALL campanulatas get banned, even the named forms that never set seed. This is a problem we gardeners have brought upon ourselves. The record of garden escapes into the wild is not a proud one and too many gardeners don’t take responsibility for their weeds.

Prunus Pink Clouds - one of the sterile forms raised here by Felix Jury

Prunus Pink Clouds – one of the sterile forms raised here by Felix Jury

Mark’s father, Felix, was a fan of the campanulatas and he bred a few. “Pink Clouds” has an attractive weeping habit and an avenue of them has been a feature at Auckland Regional Botanical Gardens. I assume it is still there. “Mimosa” is more upright and flowers a little later. “Petite Pink” is probably no longer available commercially but is a dear little tree that never gets much over two metres in height but has all the appearance and shape of a proper tree. The thing that sets these three apart is that they are all sterile. They don’t set seed so are never going to become weeds. All three are in that candy floss pink colour range.

Prunus “Felix Jury” was named for him by Duncan and Davies (it is not the done thing, dear readers, to ever name a plant after yourself) but it was of his raising. It is a much deeper colour, carmine red, and a small growing tree. What it is not, alas, is sterile so if you see it being advertised as that, the nursery or garden centre is wrong.

It seems to be quite difficult to find reliable information on the seeding habits of other cultivars on the NZ market. If anybody knows more on this topic, please let me know. Every year at this time, Mark starts to talk about doing some more work with campanulatas to raise more sterile forms. We know which ones are sterile in the garden but the best one is a rather large tree for most people on small urban sections. It would not allow you to fit your house on the plot as well.

Petal carpets supreme

Petal carpets supreme

I can also tell you that one of our most common weeds here is seedling cherries and we are vigilant and persistent. If you live anywhere near native bush or a reserve, you should take great care to grow only sterile forms or to avoid them altogether if you are not sure. If you live in town with a seeding specimen, your neighbours probably grit their teeth at the seedlings that pop up in their place.

If you can manage the weed potential, the explosion of bloom in late winter is wonderful. Taiwanese cherries flower much earlier than their Japanese counterparts and are nowhere near as susceptible to root problems in wetter climates, so they live longer. Nor do they suffer from witches’ broom which can take over the Japanese types. It is when part of the tree grows much more densely and vigorously and fails entirely to flower. Left to its own devices, witches’ broom can take over the entire tree and the only way to deal with it is to cut out affected sections. It is very obliging of the campanulatas to be resistant.

The tui would be most grateful if we could just get this right for them before all campanulata are banned are noxious weeds.

First published in the Waikato Times and reprinted here with their permission.

Plant Collector: Aloe ferox

Aloe ferox - very orange and loved by waxeyes at this time of year

Aloe ferox – very orange and loved by waxeyes at this time of year

The waxeyes are delighted by the flowering of this aloe and the vertical flower spikes are often populated by at least half a dozen of these cheerful souls. This is a particularly spiky aloe, coming, as many do, from the coastal areas of South Africa. As such, it prefers a dry climate, warm temperatures and sandy soils. None of these apply here, so presumably it is fairly forgiving but it will rot out without excellent drainage. It is a very heavy plant on top so what is happening below ground is important. Wikipedia tells me that each fleshy leaf can weigh up to 2kg when it is harvested. And why is it harvested? It is not just the better known Aloe vera (or ‘ello, ‘ello, ‘ello Vera as we refer to it here) that has useful attributes. A. ferox also has medicinal and cosmetic properties and is a commercial crop. With its fiercely spiky leaves, you would want to be wearing leather gloves at harvest time.

There is nothing rare about A. ferox, except in the wild where it is endangered. It is widely available in the marketplace. In optimum conditions, plants can reach 3m tall, but after many years ours still sits at half that height. We may have problems if it reaches its potential.

Aloes are a very large family of flowering succulents from the African continent. Many are winter flowering, presumably triggered by seasonal rains.

First published in the Waikato Times and reprinted here with their permission.

Garden lore

[My garden] is a confusion of kitchen and parterre, orchard and flower garden, which lie so mixt and interwoven with one another, that if a foreigner, who had seen nothing of our country, should be conveyed into my garden at his first landing, he would look upon it as a natural wilderness, and one of the uncultivated parts of our country.

Joseph Addison, The Tatler (1710)

The dreaded buxus blight - but not in our garden

The dreaded buxus blight – but not in our garden

Buxus blight
Judging by all the search engine terms I see leading people to my website (www.jury.co.nz), buxus blight is currently running rampant. In summary, if your buxus has turned brown all over, it is dead. If it has big dead patches and some green left, odds on you have buxus blight. All species of buxus get it but it is worst on the most common ones we use here – B. sempervirens and var. suffriticosa. It is a fungus – cylindrocladium – and it is a problem throughout the world where buxus is grown. Being a fungus means that it is spread by spore and these light little packages of blight can be spread by wind.

You can treat buxus blight but you can’t cure it. As soon as you stop treating it, the dead patches will start again. Untreated, you are likely to lose the lot eventually and it will look most unattractive in the process. I know of people who are keeping it at bay by using copper sprays and there will be fungicides that will knock it on the head for a while. The trouble is that the repeated use of copper sprays is not good for the environment (eventually you can get a build up that kills earthworms) and fungicides are not the nicest of sprays. It is unlikely that natural sprays using baking soda are of sufficient strength to be effective.

In the end, the decision really is whether you are willing to spray your buxus from here to eternity. Be grateful if you do not have the blight.

First published in the Waikato Times and reprinted here with their permission.

Tropical gardens re-created in Asian hotel-style

The distinctive spindle palm or Hyophorbe verschaffeltii at Kota Bharu airport

The distinctive spindle palm or Hyophorbe verschaffeltii at Kota Bharu airport

I mentioned I had been to the tropics. It was Malaysia and included the magical Perhentian Islands which were pretty much a perfect tropical hideaway. Waving palm trees, golden sand, warm sea with coral reefs just off the beach, no roads, so no vehicles, not even motor bikes. All transportation was done by small boat and wheelbarrows. What they did have was a sewage system and a daily rubbish collection (by boat) which is always reassuring.

The wheelbarrow as the main transporter of freight

The wheelbarrow as the main transporter of freight

Did I come home with a yen to re-create my holiday experience by building a tropical garden? Well, no. See, there is something missing here. The temperatures in the tropics are consistently in the 30s. Soggy, cold tropicalia in winter does not seem so evocative of warm holidays, in my opinion.

Many others do not share my reservations, however, and the tropical garden has become increasingly de rigueur, particularly in Auckland but also in points further south where the folly is magnified by even cooler temperatures.

It occurred to me that we may have evolved our own tropical gardening style in this country. It is perhaps best described as “cool climate Balinese-hotel-style” or, if you have been to Bali, even more specifically as “Ubud hotel-style”. I have never seen that garden genre beyond a hotel environment in the tropics and it does not reflect the wider environment.

In Malaysia, the closest I saw to domestic gardening was more akin to a food forest. The focus was on production, not aesthetics, so tended to feature a mango or two, coconut palms, plenty of bananas and maybe a breadfruit. Ornamental gardening is more likely to be limited to a bonsai bougainvillea in a pot.

Nor does the forest resemble a tropical garden as we understand it and our domestic, cooler climate version cannot be seen as an interpretation of that. Besides, we lack the monkeys (big, long-tailed ones ripping the beachside abutilons apart when I saw them).

Fake trees in Kuala Terengganu

Fake trees in Kuala Terengganu

Plantings for beautification are clearly the domain of the public sector and commercial entities (hotels, in particular). Growing conditions are pretty forgiving in the tropics. They can often cut things off and stick them in the ground with no special preparation and a reasonable expectation that they will grow. I saw Cordyline terminalis treated in this very fashion, growing in pure sand. So it was a puzzle to me as to why the riverside in Kuala Terengganu was furnished with fake trees. Fake trees designed to look like Norfolk Island pines and oak trees colouring up for autumn, in fact. Bizarre. Yet the street trees included the much favoured and very fragrant Michelia alba which is devilishly difficult to propagate in this country.

Blocking off a street in Kota Bharu

Blocking off a street in Kota Bharu

As in so many Asian countries, it is possible to beautify cities with planters, often ceramic. Indeed, I saw a row used to temporarily block off access on a road in Kota Bharu. Anyone want to take bets on how long these would last in any New Zealand city? It is just one of those unspoken reminders of the vandalism and theft we live with. No council is ever going to contemplate using something as easily destroyed, let alone putting little clipped topiaries into them.

The two dimensional traveller's palm is in fact not a palm at all (Ravenala madagascariensis,)

The two dimensional traveller’s palm is in fact not a palm at all (Ravenala madagascariensis,)

Palms are planted everywhere and the public plantings go well beyond the ubiquitous coconut palms and the utility monoculture of the palm oil plantations. The beautiful bismarckias and curious two dimensional traveller’s palms (which is not a palm but actually related to strelitzia) are certainly stand-out plants.

Frangipani - usually seen as a hotel garden plant

Frangipani – usually seen as a hotel garden plant

Underplanting? The only places I saw underplantings were on roadside verges and in hotel gardens. These are commonly the tropical crinums and ornamental gingers. The gorgeous frangipanis which we associate strongly with the tropics are mostly in hotels. Of course these are Central American plants, not Asian. Mind you, so too is the bougainvillea and it has done pretty well in establishing itself as a first choice plant in warmer areas across the globe.

All of this made me realise that the many “tropical gardens” in tropiNZ are eclectic mixes of plants from around the world put together in the classic layered style, but tidy. We won’t accept the wild abandon of tropical growth, the droop of scruffy banana leaves, the debris and litter of the forest floor. No, this is warm climate plants put together with a little tasteful Asian ornament or two, straitjacketed into suburbia.

In fact the model is those immaculately groomed gardens you find throughout Asia in better quality hotels. Presumably for many such garden owners, the evocation of happy, holiday memories centres primarily on their hotel and the hotel pool. It does not have a whole lot to do with the wider environmental or actual gardening in the tropics. As I said, Ubud hotel-style, but without the warm temperatures.

First published in the Waikato Times and reprinted here with their permission.

Plant Collector: Rhododendron ‘Pukeiti’

One of the big leafed rhododendrons, "Pukeiti" (otherwise known as R. protistum var. giganteum)

One of the big leafed rhododendrons, “Pukeiti” (otherwise known as R. protistum var. giganteum)

This is the iconic plant of Pukeiti, the rhododendron gardens set near Mount Taranaki. It is one of what is widely referred to as the big leafed rhodo group, grown in those gardens in the Valley of the Giants though this plant is on the cold hillside of our park here at Tikorangi. In the rhododendron world these are big – big leaves can be up to 50cm long and big flower trusses on large growing plants which, over time, can reach 5 metres tall by about 8 metres wide. These are not plants for the urban garden. While the plant itself is hardy, an untimely frost can turn the blooms to something resembling caramel icecream.

“Pukeiti” is a selection of R. protistum var. giganteum which itself a straight species. It was grown from seed collected by the intrepid plant hunter, Kingdon Ward, in the highlands of North Burma in 1953. It has a deeper colour than most of the other big leafed types we grow, with a big full truss of 30 individual blooms. These are described as funnel shaped and campanulate in form – slightly flattened, tubes which flare out to a frilly edge in non-technical language. The display this year is particularly good. We are hoping we don’t get a late frost.

First published in the Waikato Times and reprinted here with their permission.