Autumn is a time to look at trees even if we can’t compete with the seemingly endless blazing colour of countries like Canada. A friend from Te Popo Garden, inland from Stratford, commented in passing that it didn’t get much better than last weekend with the sun streaming through the autumn leaves on the trees. We have had remarkably little wind recently and a sharp drop in temperatures from the Indian summer straight into winter chill, so it is shaping up to be a splendid display.

It should not be necessary to point out that you only get spectacular autumn colour on deciduous trees which shed all their leaves each year. I thought everybody knew that, just as I thought that everybody knew that our native flora is pretty well all evergreen. Ergo, we do not get autumn colour from our native plants. This did not stop an enquiry a couple of months ago about whether we have places noted for autumn colour in Taranaki and (wait for it) were any of these native trees, for example a grove of kauris. I could accept that the enquirer did not know that kauris do not occur naturally this far south, but I did wonder what had happened to general knowledge that nobody in the chain of this particular organisation had picked up on the fact that our native plants do not colour up in the way that some deciduous plants do. There are subtle seasonal colour changes at best in our native flora but for the golden leaves or the fiery reds and oranges of autumn, you must look to imported deciduous trees and shrubs such as maples, poplars, parrotias, gleditsias and cornus.

It is the sharp drop in temperatures which triggers the plant to stop feeding its leaves and let them die and drop. Inland areas are colder at night so they get significantly more impressive autumn colour than those of us closer to the coast who just gradually drift from one season into another. And coastal points northwards (Auckland and Northland) get even less autumn colour. Travellers in the tropics will know that you don’t get autumn colour at all in hot climates.

That said, Prunus Awanui has been a vision of golden leaf this past week. The wisterias and rugosa roses always surprise me with their autumn colour and the grape vine which covers the large verandah out from my office is a delight every year. It looks as if the sun is shining on even the greyest of autumn days.

But while admiring the trees in autumn, gardeners may also like to do some critical analysis on the merits of the different trees in their garden. We have been talking recently about the failure to differentiate between short term nurse trees and long term trees.

In our windy country, we need nurse trees. They are a quick and cheap option to grow in order to provide some protection so that longer term, quality trees (which by their very nature tend to be slow growing) can get established. And because nurse trees grow quickly, they can give height and impact in a garden in a surprisingly short space of time. But few nurse trees in our climate age gracefully and there comes a time when decisions need to made about which are worth keeping and which have frankly passed their use-by date. Not all trees are equal and not all trees improve with age.

Many gardeners make one of two mistakes. They either overplant badly and then fail to discriminate a few years down the track as to which are the good long term trees worth looking after, even if it means cutting out the filler trees. Or they plant specimen trees out in exposed areas in solitary confinement.
In using nurse trees, you are learning from nature. When bush regenerates, the nurse plants are the first to get established and to create some cover. In that protected environment, the longer term trees come through and are forced up in search of light. In due course they supersede those nurse plants. Without the protection and microclimate of nurse trees, they can be too exposed, stunted and often multi trunked because they do not need to shoot up in search of light.

Trees are going to become a great deal more important in the immediate future. The talk about carbon footprints, climate change and sustainability is not just a fad which will fade away in a few months. We are in a time of radical change and long term trees will be part of our future and quite possibly part of the survival of our planet. The day may not be far away when we are shamed by our outdoor furniture made from Indonesian hardwoods.

While tiny town sections are not going to accommodate forest giants, neither is an espaliered apple tree going to save the planet (though it might help feed the family and taste better than cool store apples). But gardeners with a bit of space (or non gardeners for that matter) could and should be thinking about planting long term trees and treasuring existing trees which have the potential to outlive most of us. By long term trees, I mean those with a lifespan which will be fifty years at least, maybe a hundred and some have the potential to live many hundreds of years if they are planted in the right position. In New Zealand we have a tendency to think in terms of ten or twenty years and far too few trees are allowed to ever reach maturity.

So by all means plant pretty flowering cherries, albizzias (though I think I have seen those on a banned list somewhere), gleditsias, paulownias and birches. But see these for what they are, which are short term trees and look to using them as cover to get some good trees of potential longevity established. It doesn’t have to be a mighty kauri, rimu or totara though goodness knows, we plant too few of our majestic native trees. There are some magnificent members of the conifer family which are not native – the sciadopitys or Japanese umbrella pine is a gem and the somewhat maligned Norfolk Island pine is a great statement of form on the landscape. Magnolias can live a very long time and are unparalleled for splendour in flower. Liriodendrons give brilliant autumn colour, as do scarlet oaks, ginkgo biloba and even plane trees. All get more impressive with age.

If you are unsure what you are doing, seek out advice and never plant any tree anywhere near power lines. It will come off second best in a tangle with the lines companies. The challenge is to make sure that you plant some good, long term trees in your lifetime. What better legacy to leave?

We had cause to go to Auckland last week and were reminded once again of the charm of the wildflower plantings down the centre of the motorway. Driving out of the city on Saturday morning, we slowed to the expected crawl. Auckland can lay claim to having the most expensive stretches of motorway built for moving high volumes of traffic at reasonably high speeds but in fact accommodating vehicles which are relatively frequently travelling at 10 km an hour. In this case, workmen were repairing a central crash barrier and this necessitated closing one lane entirely despite the very wide median strip. But it did mean we could enjoy the wild flowers at a crawl. It was the cosmos that dominated this autumn, both cerise and white along with a sprinkling of yellow daisies and something blue (we couldn’t stop to do a full identification). Wildflower and meadow plantings are exempt from the modern requirement for colour toning.

Many years ago when the children were little, we took them on a camping trip around Nelson and were enchanted by a meadow garden we found. It was a field of mixed annual flowers up to waist height and the charm lay in the simplicity and nostalgia, not in design, form or plant composition. We came home inspired and did a bit of dibbly dabbling and research before we came to the conclusion that this is a garden style best suited to harsher climates. The Auckland motorway median strip represents pretty harsh conditions.

USA is renowned for its prairie gardens where mixed grasses and wild flowers can co-exist and return every year to delight afresh. North America has many native wild flowers so these are growing in their natural habitat.

Similarly, Britain has long established meadow gardens where native wildflowers can live in amongst the grasses and meadow gardening is recognised as being of both ecological and aesthetic merit. Western Australia is known for its spectacular wild flower season and parts of Southern Africa must put up splendid seasonal displays with the wealth of different bulbs which are indigenous to that area.
New Zealand lacks most of the native wildflowers and bulbs which give rise to natural meadow gardens and the imports that have thrived here don’t quite cut the mustard. Arum lilies and agapanthus can not foot it with Britain’s ground orchids such as the dactylorhiza. Anything that naturalises in this country is more inclined to be a thug than a treasure. It is possible to manage a perennial meadow garden here but it is not the easy care style requiring minimum labour that it is in other countries. And wildflower meadows are even more difficult to manage, having to be treated as an annual labour of love rather than a self seeding, ongoing venture with just a once a year mow required.

I suspect that anywhere that is good dairy land is not going to be good wildflower or meadow country. The reliable rain, good soils and benign temperatures mean that we get rampant grass growth for most of the year. So the grasses choke out the wild flowers and discourage them from gently self seeding. And every gardener knows that weeds are thugs. Left to their own devices, the law of nature says the thugs will dominate and it only takes a year before the undesirable weeds have such a hold that the charm of the wildflower field or meadow has been swamped by dock, dandelion and hawkweed and you are faced by a paddock of out of control weeds.

Internationally, these wildflower displays occur in areas where summers are dry and often hot and where winters are very cold. Thus the plants stop growing in both summer and winter. The triggers for plants to grow in these conditions are either autumn rains or the rise in temperatures in spring. Plants under stress will often respond by putting on splendid floral displays (it is the survival urge to flower and set seed before they die) and the harsh conditions of summer drought can trigger flowering. In Taranaki, the message to most plants is just to keep on growing so we can end up with disproportionate amounts of green foliage instead of blooms.

All of this means that if you covet a field of charming, summer wild flowers, you are probably wasting your time unless you live in an area such as Pukearuhe or coastal Waverley where the poorer and drier conditions will accommodate them better. And you will have to create it with imported flowers. New Zealand evolved as forest in the main, so we lack the pretty seasonal annuals.

Meadow gardens can be managed here, sort of, though it is much easier to do it with bulbs that with annuals. By definition, a meadow garden should be low maintenance so you want to keep the thugs right out of it from the start. And if you are thinking of planting intensively with herbaceous perennials such as primulas, essentially you are creating an informal herbaceous drift rather than a meadow garden. A meadow garden is a mix of grasses and naturalised plants. In spring, many of us do it with daffodils, bluebells, snowflakes or, if you are Mark, proper snowdrops but really, a meadow garden should have a much wider range of plants all co-existing in a gentle sort of way. All we are doing with the bulbs is naturalising them rather than creating a self sustaining mixed habitat.

A wild garden is often included in large English gardens and it can sit quite happily alongside more formal areas of topiary or well tended borders. Sadly, we are resigned to the fact that this is not a technique readily transplanted here and the wild garden is almost guaranteed to look like an unloved and unkempt wasteland. But then we do have compensations. Here the impending winter is not a sign of low light levels, abominably short days, general greyness and a complete lack of flowers. The sasanqua camellias are already in flower and we will continue to flower different plants all through autumn and winter. It is probably only eight weeks or so until the magnolias in Powderham Street next to the radio station start to flower and then we can feel spring is imminent.

After my garden visiting weekend in Marlborough, I came home feeling that I was suffering from DEBBO. That is Death by Buxus Overload. You can have too much of a good thing.

I will admit that we have the odd metre or two of buxus hedging ourselves and it certainly makes a tidy little hedge but the bottom line, as Mark is inclined to observe, is that box hedging is grossly over used and is basically boring and clichéd. He has never been a buxus fan.

I have been told by overseas visitors that in New Zealand we use clipped hedging a great deal. If that is the case, it probably started for two reasons. One is that we live in a windy country and most gardeners need to establish wind breaks. The second reason is that plants in this country are ridiculously cheap by international standards and planting a long hedge is usually a great deal cheaper than using permanent materials such as brick or stone and we can do it ourselves in an afternoon. It is this second reason that is probably responsible for the cumulative hundreds if not thousands of kilometres of low clipped hedges, mostly buxus, that we feel driven to plant to define the bounds of individual gardens.

Buxus is an infinitely handy little plant. It is so easy to strike from cutting that it is within the reach of even novice gardeners. And because it is so easy and so common, if you decide to buy it, the plants are cheap as chips. It does not grow too fast so you can get away with clipping just twice a year. Even if you cut it back to bare wood, it will shoot again and bush out. It will grow in harsh conditions (though it can get a bit yellow-ish at times) and tolerates rough treatment. Its main problem is the nasty fungus which is attacking and killing plants in warmer areas but has yet to be a major problem locally. All of which means we probably have our share of buxus kilometres in Taranaki gardens too. Even the lake in Pukekura Park has a buxus hedge which has always struck us a little redundant.

We have not yet felt such dislike of buxus that we have ripped out our modest metreage but at the first hint of buxus fungus we will be reaching for the saw and spade, not for the sprayer. And for some years we have been reviewing other options for neat clipped hedges. The big problem is that there is nothing that roots as easily and is therefore as cheap as buxus let alone its fine, small foliage. But there are options with better coloured foliage which will take cutting back hard and form dense little hedges.

Top of the list are some of the small leafed camellias. We have trialled various options here and our short list of suitable camellias for dense, clipped, small hedges includes brevistyla (which also suckers a little which is no bad thing for a hedge), microphylla and minutiflora (all species with small white flowers. Some of the very slow growing miniature camellias could also be used for clipping in to tidy hedges. Others, like Fairy Blush, Night Rider or transnokoensis can make great intermediate sized clipped hedges.

Some of the species camellias will set seed relatively freely so if you are patient, you could raise the seed to get cheap hedging. Seedlings are not identical (unlike cutting grown plants which carry all the same genes as their parent) but for a clipped hedge they should be close enough.

If you feel compelled to have buxus hedging in your potager (though why anyone wants to eludes us because it takes up valuable space, sucks nutrients and moisture out of the soil and provides a perfect hiding place for snails) you may like to consider a clipped edging of Camellia sinensis instead. If you gathered the clippings and fermented them, you could even aim to be self sufficient in tea. I saw cranberries pruned hard in a Blenheim potager. In that case they were lollipops but there is no reason why they could not be hedged. Locally, Te Popo Garden had hedged cranberries last time we visited. The ripe fruit has a wonderful aroma.

My short hedge of loropetalum chinense (the green form; we are conservatives here and rather of the view that hedges are best green, not in-your-face burgundy or chocolate or even grey) is thickening up well and only needs a passing trim twice a year.

In frost free areas, compact little vireyas Saxon Glow, Saxon Blush and Jiminy Cricket (all sister seedlings) make a tidy and attractive little hedge. Vireyas root easily so you could buy one and try your hand at cuttings.

Totara can be clipped heavily and becomes more dense, sprouting even from bare wood and forming a really classy indigenous hedge. It is a bit prickly when it comes to clipping and the prunings are not exactly ideal in the compost heap but because of that, it is also a burglar and child proof hedge. It is extremely hardy and long lived. Our remaining length of tightly clipped totara hedge dates back to the end of the nineteenth century and it is still dense and only two metres high. Some of the fine leafed coprosmas and corokias are other native plants which lend themselves to clipped hedging. The Aussies love our pittosporums for hedging but you need to be selective about the colour of the pitto you chose as some can be rather pale.

We are very lucky here to have an in-house hedge trimmer who takes great pride in getting them looking sharp, to the extent that he uses string lines and a spirit level. But we certainly would not contemplate planting a hedge that needed trimming more than twice a year. For that reason, we shun the popular teucrium and lonicera which certainly make good, quick and cheap hedges but need your attention a great deal more frequently than twice a year. In fact to keep those two looking good, it can be closer to twice a month in the peak growing season.

Next time maybe : NAB C BAT. That stands for Not Another Boring Clipped Bay Tree. And yes I do have a large lollipop bay tree (laurus nobilis) but it is in the vegetable garden where it is acceptable (it is the culinary bay and belongs in the herb garden) though it does get thrips in our climate. There are other plants besides buxus and bays that you can topiary as punctuation marks in the garden. Seeing some originality and flair in plant selection can be like a breath of fresh air for garden visitors who will often see the same plants used in similar ways in multiple gardens. Deliver me, please, from any more buxus and bays.

There is a bit of the green-eyed monster in many of us who live in areas of the country where vineyards are rare or non existent. A visit to Marlborough had me thinking that the green-eyed monster may be wearing rose coloured spectacles with visions of the romance of Tuscany.

Vineyards in Marlborough are acre upon acre upon acre of green monoculture. And frankly there is not a lot that is aesthetically pleasing about endless expanses of tanalised posts, wires and alkathene piping. And while the vineyard cafes, for which many of us would also admit to feeling envy, are generally magnificent, architecturally designed buildings from the front, if you view them as a whole, the backs of the buildings are factories. Stainless steel vats are not great additions to the rural landscape.

Vast vineyards mean little bird life. Birds and grapes don’t go together and stringent efforts are made to kill or at least banish all birds. But worst must be the frost control in an area which has fairly frequent frosts. A local told me that there could be as many as 150 helicopters hovering in the air. I was a bit surprised that they could muster 150 helicopters but the vineyard acreage is huge now. I imagine Apocalypse Now has nothing on these areas and the prospect of long nights with the throbbing of helicopters ensuring the survival of the precious grape crop (while discharging vast quantities of exhaust fumes) would have me selling up and moving to somewhere less likely to be afflicted by deafening noise while I struggled to sleep.

So a recent weekend in Marlborough was a revelation in dispelling the myths of the glamour of living in a grape growing region. Good wine (and plenty of it), good food in vineyard cafes and lots of wealth but the environmental impact is not all great. And in Marlborough, which is dry as a bone, vineyards all need irrigation. With no ground water (so no springs, wells or bores) I was told it all derives from the one river. The current buzz word elsewhere of sustainability was not mentioned. Overall, I concluded, Tuscany it is not.

I was in the area for a weekend looking at gardens in the company of some of the country’s pre-eminent and up and coming gardeners. The first garden had me thinking about whether it was in fact a garden or a landscape but that is pedantic because it stands out as the most sensitive adaptation to the environment that I have seen. We were lucky to see it because it is not open to the public. The house was the initial unique feature – thick concrete poured in curves and completely nestled into a hillside so that it is nearly invisible. In fact, as we walked towards a windowed cupola which appeared to be a garden feature set on a grassy mound, it took a few moments to realise we were walking over the roof of the house. The glassed cupola was the light and ventilation shaft for the kitchen. Entering through a cutting in the hill flanked by ngaio trees, we walked into this curious, curved house where there was a wall of windows looking out to the landscape and the sea. It took your breath away. Living in a hobbit house which is half underground may not appeal to all but I have never seen such sensitive blending of architecture and landscape. It was all of a two minute stroll to the wild coastline and the environment is harsh and unforgiving but simply splendid. Gardening in a traditional style would be doomed to failure but the owner has maximised two view shafts while retaining some shelter from the existing dunes. Vegetation was entirely native and tough – including ngaios, cabbage trees, flaxes, tussocks and toetoe. It looked as if it was all a happy, natural occurrence and it wasn’t until I looked closely that I realised the owner had worked hard to achieve this impression. I figured the land had been re-contoured somewhat to achieve the view shafts (he confirmed that he had indeed bought a bob cat and owned diggers) and I could see where he was managing the native flora to keep a natural appearance without the scruffiness of the wild. But nothing looked contrived or artificial and it was simply remarkable.

Inland from Blenheim, we visited Barewood – Carolyn Ferraby’s garden which carries national significance ranking. Her place was very different with the prettiest garden in combinations of pastel perennials, annuals and shrubs surrounding a very old villa. A florist by profession, she has clearly shunned anything bright or garish and I certainly can’t recall seeing anything spiky. I think of it as an English-styled mixed border approach to gardening and it was the sort of place that my English mother (herself a very good gardener) set about creating in her many gardens but never stuck around long enough to see mature. Harmony is the key, and deceptive understatement. Nothing shouts look at me, look at me. Blending together to create a complete picture is the order of the day. The only mass plantings are the three avenues of matched trees which frame access ways but many of the border plants are repeated in different combinations. Considering we were viewing it at the very end of a dry summer when most gardens can look a little tired and stressed, the owner maintains a high standard with the help of irrigation. It was very pretty.

Southwards, near Kaikoura, we visited Winterhome, another Garden of National Significance. I have never been there before though I have seen it frequently on TV and in magazines where the rose gardens (massed planting of white Margaret Merrill in compartments surrounded by box hedging) and the canal garden feature heavily. Those simple forms photograph well but never inspired me so I was completely unprepared for the impact of this large and mature garden which went so far beyond those two areas. It is Italian in style with intersecting axis but on a fairly grand scale and a complexity of planting which goes beyond the modern formal style with its very limited palette of plants.

This is a garden light on ornamentation (thank goodness) but heavy on structure and form. Lots of walls, loggias, pillars and structural framing but all integrated with planting. It is a garden which has surprises and mystery and where some of the long axis (very long, some of them, stretching hundreds of metres) entice you down to see what is at the end. The structure, or hard landscaping, has aged gracefully so it is not intrusive but gives it all shape and coherence.

I was forced to review my cynicism about the Italian look (all structure and form with no plant interest and usually clichéd structure at that). While I may feel a little sense of NABBH (more of that in a later column – it stands for Not Another Bloody Buxus Hedge), it was great to see gardeners carry off a grand vision with flair and hard work, albeit probably backed up by quite a bit of money.

Barewood and Winterhome are both open to the public but you have to know the right people to get entree to the coastal house and garden.

Over the years we have hosted many thousands of garden visitors and inevitably one develops a sort of patter. “You will notice our climate is very soft,” I say. “We never get that hot but we never get very cold either. High sunshine hours and regular rain twelve months of the year, including summer rain. If we get three weeks without rain, we start talking drought.” Hah! When did we last get a good, steady rain which soaked well into the ground? Considerably longer than three weeks ago. And we are talking fairly serious drought now.

Given that we earn our living from growing plants which require irrigation, we are at least lucky to have a reliable water supply. When we had a bore drilled well over twenty years ago, I recall it being one of the most stressful periods of my life. That was back in the olden days when it wasn’t easy to borrow money. You actually had to have some equity and be able to prove that you could meet the repayments and the then Rural Bank would not loan us the money to put in an irrigation system until we had found water. We had scraped together enough money to get the hole drilled but of course you pay wet or dry. In other words, if we had the site wrong and they drilled down but failed to find water, we were still going to have to hand over our hard earned $4500. It was a very long ten days and, as luck would have it (though we did have a somewhat more cynical take on it at the time) when Mark told the drillers we only had enough money for one more day, water magically appeared. Whatever, it is a supply that has stood us in very good stead in the decades since.

We have never irrigated the garden however, and I am strongly of the view that in these changing times, putting in ornamental gardens which rely on irrigation is unjustifiable and unsustainable. This year’s drought may be a one-off or it may be a taste of things to come. But the global shortage and increasing unpredictability of fresh water is hitting home at such a local level that gardeners should be considering where they and their passions fit in to the bigger picture.

We don’t expect to lose much at all in the garden and certainly no big trees or shrubs. The hydrangeas are wilting and other plants are visibly stressed. We are getting some early autumn colour as deciduous trees are deciding to shed some of their foliage early to reduce moisture loss. But this being Taranaki, we are confident that the autumn rains will come in due course and at least the cooler nights and increasing dew helps reduce overall moisture loss.

Vegetable gardeners will be continuing to water and the quick growth and high moisture content of many edible crops mean that if you don’t water, you won’t get a harvest. But short of ripping out your ornamental plants and putting in succulents and desert plants which are designed to withstand long dry periods, what can you do in the ornamental garden? The answer is pretty well nothing at the moment except to make plans for when the rains return.

Well cultivated soil holds water better in dry periods. In fact, tilling the vegetable garden to a fine tilth and letting it form a dry layer on top is a time honoured method of conserving water. We are pretty lucky in most of Taranaki and Wanganui that we do not have the nasty clay soils that afflict much of the country. Clay tends to be waterlogged in winter and to set like concrete is summer. Most of us have soils which are pretty easy to cultivate. So if your garden soils look compacted and you have developed the habit of chipping out a hole to place new plants, make a resolution to put more effort into cultivating the ground. Every good gardener knows that the state of the soil is the single most important ingredient to gardening. Even novice gardeners may have noticed that they buy a superb looking plant, bung it in the ground and it starts to go off in a most disappointing manner. The cause is usually bad planting technique.

So step one is to cultivate the soil well. Adding compost, humus or well rotted animal manure helps to add goodness and texture and is a great deal more sustainable and environmentally sound than adding artificial fertilisers. After all, humans have been gardening and growing crops that way for thousands of years, long before the merits of phosphates and nitrates were proven in the nineteenth century, triggering the rush from gardeners and farmers for old bones to crush for fertiliser.

Step two is to plan for planting trees and shrubs in autumn, rather than spring. Most of us get inspired by pretty spring plants but it really is better to get them into the ground in autumn so they can establish and get their roots out before the threat of summer dry. But don’t be tempted this year to start planting until we get rain. The calendar may tell us it is autumn but the conditions are not yet singing to the same tune.

Step three is to mulch. And mulch. And then mulch some more. It is too late to mulch when the soil is already dry because the mulch will act as a barrier to water entering the soil as well as to slowing evaporation. You need to mulch when the moisture levels are already high, in winter or early spring. We mulch with compost and since the advent of our prized chipper, we now have the shredded waste from that too. You can mulch with pea straw (an expensive option here because we don’t grow peas locally), pine needles, granulated bark, calf shed wood shavings or any similar material. You want it pretty sterile so you are not introducing weed seeds. The mulch retains moisture in the soil, adds texture to it and some mulches will add nutrients. It also makes a garden look a great deal better than bare soil. The birds tend to find it appealing but rather than moaning about them scattering the mulch, look upon it as beneficial all round. Not only does it keep bird life active in the garden, but they are digging in the mulch because it is rich in natural insect life.

Step four is my new hobby horse. Plant trees. If you are worried about the sun, plant deciduous trees which will give shade in summer but not block the precious winter sun. I used to think that if everybody planted one good tree in their lifetime in a spot where it would have every chance of growing to maturity, the world would be a better place. Now I think that planting many trees is a better way to go. If you drive to work, or insist on driving a gas guzzling large car or urban tractor, enjoy motor sports (there is an oxymoron for you), fly internally or overseas or (horrors), all of the preceding, then you should be planting many more trees to compensate for your excessive carbon hoofprint.