Sunday, April 13, 2014

Variegated Ginkgos

I was talking plants with a few friends during the week and the topic turned to plants we never expected to see.  You know what I mean – something you stumble upon in a garden that you have never even read about, and you look at it, not quite sure what it is, and then when you work out what it is, you think – “I never would have thought of that!”
I had a moment like that a few months back in the delightful ‘Tupare’ garden in New Plymouth.  The Head Gardener and I were strolling through the garden on a drizzly summer afternoon, having almost the entire garden to ourselves, when we stopped to look at a tree with green leaves, splashed with white lines radiating out from the centre of each leaf.  It took me a minute to realise it was a variegated Ginkgo, but a second’s reflection made it obvious.
There was the same light coloured bark, and there were the same Ginkgo leaves, with their veins spreading out from the leaf stalk, but instead of being the usual dull green, here they were  irregularly splashed with streaks of white.  It is probably more interesting rather than dramatic, but would make a great talking point in a moderately sized garden.
It would be especially interesting at this time of year, when the green colouring would be replaced by gold, giving a butterscotch and ivory sort of look to the trees.
Ginkgos are interesting trees, if a little large for most small gardens. They are ancient conifers, although they look not the least bit like a pine tree.  They have male and female trees, and unless you love the scent of rotten socks, I suggest you hunt out male forms.  The males tend to make a tidier pyramidal shapes, while female forms correspondingly tend to spread more.  And of course, they also bear fruit which contain the famous ginkgo nuts.
If you have never had the pleasure of smelling these fruit, all I can say is that you are very lucky.  It is almost indescribable, but perhaps seven day old socks, mixted with the most pungent blue cheese you can imagine, with an undertone of dog excrement gives you a hint. And I can tell you, having had the misfortune to pick one up, the smell does not go away, even with repeated rinses.  The dried nuts are an Asian treat, but the young nuts smell rather similar to the fruit  although they are said to have a sweet taste with a cheese-like undernote.

Sunday, April 06, 2014

Not much to look at, but ...

A minor star of the native plant world that is showing off at this time of the year is one you might not even notice – the once ubiquitous Golden Ake Ake, Olearia paniculata.  This is a very tough coastal daisy – again a New Zealand native – which was once quite commonly grown as a hedge.  It has light yellow/green leaves which are covered in white hairs on the lower side.  These leaves can be flat but are more usually very wavy, and they are born on orange stems.  If the plants are grown as small trees and are allowed to develop a trunk, the bark has wonderful texture.  One catalogue I looked at described the bark as ‘stringy’, which is hardly a flattering way to talk about delightfully exfoliating bark, although it does tend to come of the tree in strips. 
There is a mature tree near the fernery at Queen Elizabeth Park, which has this delightful bark – it is worth taking a quick detour to look at it.
However, it is this time of the year the Golden Ake Ake lets forth its greatest asset – the totally inconspicuous flowers that you would never even notice, except for one standout feature – they have the most amazing sweet and fruity scent – reminiscent of the Easter orchid. We have a couple of these trees in the backyard.  One is actually growing in the neighbour’s garden, but another has grown as a seedling of that, with much lighter foliage, so I am happy to leave it growing there.  At this time of year the scent is wonderful, especially in the evening.

There are many native olearias, all known by various forms of “daisy” – coastal daisy, mountain daisy, holly daisy.  I am sure you get the idea.  Some of them are primarily grown for their foliage, while others have pretty white daisy-like flowers. Perhaps the prettiest of the New Zealand species known as Streamside Daisy, O. chessmanii, which is smothered in white flowers each spring.

Sunday, March 30, 2014

Parrots, lilies and little ones...

Tulip 'Orange Parrot'
There are quite a number of different forms among tulips, some of which are seldom seen in lour gardens.  Perhaps the most flamboyant of all tulips are the ‘parrot’ varieties, so named because their petals are feathered, curled, twisted, or waved.  Probably the best known of these is the aptly named  ‘Roccoco’, which has swirls of yellow on deep carmine red flowers.  Even brighter is one called ‘Flaming Parrot’, which has bright yellow flowers with a prominent red stripe down the middle of each petal.  Some years ago I saw a bed of ‘Orange Parrot’ – what a stunning sight.
Lily tulips have longer and more slender flowers than most types, with flared ends, suggesting a lily flower.   They look very elegant, but there are not many varieties around in New Zealand.  ‘Pretty Woman’, which has bright red flowers with a small yellow patch at the base, is probably the easiest to find.
There are also the peculiar green tulips, which tend to have a soft coloured flower which features a broad green band up the middle of the petal.  ‘Spring Green’ is probably the best of these.
At the opposite end of the size scale are the rock garden tulips, some of which are very small indeed, but they would need to be sourced from specialist growers.  The varieties available from garden centres will probably grow about 20 cm high, and will have the usual grey-green leaves. Among these ‘Pinocchio’, which is carmine pink with a cream border, and ‘Boutade’, which is bright red, represent good value for the garden.
There is still plenty of time to plant tulips.  Unlike some other bulbs, they prefer quite a chilling over winter, so it will not matter if you don’t get them into the ground for up to a month.  Of course, by then the best selection will have gone, so it pays to get a move on.
Give them a rich, well drained soil, preferably in full sun, and remember to snip the stems when they have finished flowering, as that way they will concentrate of putting down some growth for next year’s flowers.

Sunday, March 16, 2014

Faking it

Gloriosa superba

Perhaps the most mis-used word in gardening is “lily”.  All sorts of plants are described as lilies, even though the majority of them have no botanical connection to the true lilies.  Perhaps in this context, the world “lily” just means “great looking flower that usually comes from a bulb” – or something like that.
Having said that, there are some lovely bulbous flowers out at the moment, including the stunning climbing plant, the “Gloriosa Lily’, Gloriosa superba.  There can be few flowers that are so well named, being both glorious and superb.
This is one that definitely is not related to the true lilies – in fact, it is in the same family as the autumn crocus, colchicums.  Like the colchicums they are toxic if eaten, so a little care needs to be taken with them.  They are a rather curious plant, thriving when well suited – in fact, in frost-free situations in free drain in and dry soils can even become a bit of a nuisance, seeding and establishing  too well.  They grow from a round tuber that turns V-shaped as it ages, eventually growing up to a metre long. 
From these extended tubers a succession of wonderfully coloured flowers will appear, superbly reflexed and in shades of orange-red and yellow.  This little climber (it will grow a bit more than a metre high)  makes a very dramatic addition to the summer and autumn garden, although it does struggle with our colder a little.   Find it a warm spot in the garden, or even in a deep pot, and you should have a glorious and superb flower.
At the moment the pots on our back patio that could be used to grow some Gloriosa are filled with some “Blood Lilies” – Haemanthus coccineus.  In keeping with the theme of this article, these are not actually lilies at all – they are South African members of the Amaryllis family, growing narturally in the summer rainfall areas of southern Africa.
I grow two species of the peculiar flowers.  The first, H. albiflos, is fully evergreen, with strap-like leaves that part in the summer to show flower heads that are basically a giant boss of stamen, with sepals guarding white stamen, tipped with gold.  The second species, H. coccineus is altogether  more dramatic.  Its large strappy leaves die off in the early summer, and the plant just shows the top of the bulbs over summer.  But come the start of March the bulb tips slowly part and a red flush is seen appearing.  Within a few weeks, these have lengthened and the bright scarlet spathe valves open  top shows golden-tipped coloured stamen, bearing  a striking resemblance to a coloured shaving brush.
They can be grown in warm and sheltered sites in the garden but my clump has been happily growing in a pot for the past twenty years and has flourished.

Sunday, March 09, 2014

Rejuvenating the iris beds

Photo courtesy 

Regular readers of this column will know I have a fascination for the members of the iris family, in particular the species and cultivars that make up the Pacific Coast Native Irises of North America.  A large area of the garden is devoted to a bed of these plants, from which I selected likely-looking parents for breeding, and into which I plant a couple of hundred seedlings each year.
But even though these are my favourites, I also grow quite a range of other irises, usually just spotted in between other plants in general beds. 
It might come as a bit of a surprise to learn that I have dug out a whole lot of iris plants over the past weeks, and thrown them away.  They were all bearded iris I had been growing for over ten years, and I decided that it time for me to replenish the bearded iris beds, both in terms of soil, but also in terms of replacing the varieties.
Bearded irises area little bit fussy about the conditions they will do best in, although those conditions are easily enough met.  As with most plants, it pays to consider where the plants you want to cultivate occur naturally in the wild.  In the case of the bearded irises, they almost all grow in full sun, in very well-drained soil that is derived from limestone. 
In the garden it pays to replicate those conditions, with an open sunny site, with fertile, free-draining soil with at least a neutral pH.  For my part, I added some extra compost to the beds, but also added general fertiliser and a good dressing of lime.  Most compost is low in pH and if used for lime-loving plants it pays to add some lime.  I used lime flour, which is quick acting, but coarser material, which releases more slowly, is probably better.
When deciding what to replace my old irises with I had a particular purpose – I wanted to grow some of the irises breed by the late Ron Busch, a Christchurch-based iris breeder who had bred some outstanding varieties over the past twenty years, some of which are still being released to the public.  They tend to be very colourful varieties, often with bold colours in contrast, and stitched with extra colour in a pattern that iris lovers call ‘plicata’.
I had to look around a bit but did find an on-line store that stocked a lot of his varieties, and although I could not obtain all the varieties I was interested in, I did manage to find quite a few, and they will arrive any day soon.
When I plant them out I will copy the way they grow in the wild again, placing the rhizomes on the surface of the soil, with the roots tucked in well into the soil, allowing the sun a chance to mature the rhizomes over summer.  Although some will undoubtedly flower next spring, it will be a year before they are at their best – but they will be well worth waiting for.

Sunday, March 02, 2014

Tropical flamboyance

I had an interesting chat with a gardener from just north of Auckland during the week.  She called in at the archive to talk about family history matters and to look at some papers we hold, but talk invariably turned to gardens and gardening. 
She was saying there are lots of plants she wants to grow but just cannot in Auckland – the weather is too warm, or to be more exact, it is not cold enough.  The lack of winter chilling means lots of fruiting plants are useless – her husband complained about not being able to grow currants, gooseberries and cherries – but the plants she clearly wished she could grow successfully were peonies.  When I told her about having half a dozen varieties around the garden she was green with envy.
However, I did say that there was a wide range of plants she could grow that we could not consider, and she said, yes, that was true, but she would happily give up her garden of bromeliads and succulents in order to grow peonies.
For my part, I said I loved tropical hibiscus and yearned to be able to grow them.  She snorted derisively, saying her neighbour had lots of them, as if they were slightly contemptible plants.
And therein lays the rub of gardening.  We yearn to grow the plants our climate will not allow us to, and we take for granted to wonderful range of plants that will flourish for us.  I guess it is an example of the grass always being greener on the other side of the Bombay Hills.
Although a border of tropical hibiscuses is a dream for many of us, there are plenty of places that the shrubs will grow happily enough if given a little shelter.  During my childhood our neighbour across the streets had a large shrub growing up against the chimney on her north facing wall, and each autumn it would be covered with a hundreds of soft pink flowers, each with the prominent stamen that is such a feature of these glorious plants.
Hibiscus flowers are intimately associated with the Pacific Islands, and it is a tourism cliché for a pretty young girl with a hibiscus flower tucked behind her ear to greet a tourist, but it also a reality.  They are native to the islands, among many warm places, and most of the varieties we grow in New Zealand are bred from Fijian or Hawaiian cultivars, or from hybrids between the two types.
Hawaiian hybrids are small-growing and bear the most stunning flowers of all, with bright colours in almost all hues imaginable.  Unfortunately they are also extremely cold-tender and need the warmest sites possible to flourish.  The Fijian hybrids are slightly more cold-hardy and larger growing with smaller, often fully double, flowers, although these ‘double’ flowers are rather messy to my eye.  
The bulk of New Zealand varieties used to be Fijian but Auckland nurseryman Jack Clark worked crossing the two different strains, then reselecting for those that grew well in Auckland, and his hybrids are still very popular, including one named after him, ‘Jack’, which is a bright orange double form.

Sunday, February 23, 2014

All the way from Chile, with bells on ...

Lapageria flowering in the manuka

Last week we were discussing gardening at work and the question came up about the best place to grow a Chilean Bell Flower climber, Lapageria rosea. It is an interesting question because ithe placement of this stunning plant does require careful consideration.
 Like many plants from Chile it is slightly frost tender, and if left outside on a normal fence it would soon succumb to our winters. But on the other hand, again like many of its Chilean kith and kin, it prefers a cool root run, so is not really all that suited to a northerly aspect. 
I have two plants growing intertwined – a white form and the more usual pink one – and they are happily growing up against the wall of our sleepout, on a south wall, along with some Chatham Island Forget-me-nots.  I added lots of compost and sand to the soil, so it is well drained but also has a high level of humus. 
The plants grow to the roofline each year, and each winter the frost nips them back a little.  Over the past few years they have also send some trailing branches out into the adjoining manuka and dwarf Camellia trees, but that is fine as their flowering seasons do not overlap, and it is a nice bonus to have the beautiful bells hanging from a slightly lower height.
I cannot think of a relatively easily grown climber that is as rewarding as the Chilean Bell Flower.  Mine has had intermittent flowers for the past couple of months and is now approaching the height of its season.  The white variety has flowers tinged with pink as it opens, but once fully extended has the most pristine of flowers.  The pink or rose forms, on the other hand, have waxy flowers of varying shades of pink, usually with white mottling on the inside, sometimes visible from the outside.
In the wild of Chile these plants were once harvested for their fruit, but they are now protected and are the national flower.  In the garden they are relatively easily grown, but they are difficult to propagate.  I have found the only reliable way is to grow them from seed, but it is a slow business.  They are not self-fertile, so two different clones are needed, and even then seed set is not reliable.  Once the seed is set it forms a small sausage like pod.  The seed should be sown as soon as it is ripe, as it germinates a lot better fresh than it does if it has been stored for a long time.  It takes a few years before the new plants flower.
If you have a cool spot on a south facing wall and want a special climber, you would do no better than get one of these from the garden centre.  Treat it carefully for the first year or so – slugs and snails love the fresh shoots in the spring and can quickly make a big mess of a small plant.

Sunday, February 16, 2014

Wind flowers need rain

Late summer and early autumn is a great time for us bulb lovers.  The very first of the spring flowering bulbs have started arriving in the garden centres – the anemones and freesias usually – and catalogues start arriving filled with new daffodil varieties and a range of the rare and exotic for the connoisseur. 
But this time of the year is also exiting because a number of other bulbs start to come into their own – the summer deciduous ones.
We generally associate the trait of losing leaves over harsh growing times with deciduous shrubs and trees, the majority of which defoliate for the winter.  This is because they would otherwise be in water deficit – the cold soil means the trees cannot take up much water, while they would continue to lose water through transpiration if they still had leaves.
There are a few trees from hotter climates that do exactly the opposite – they drop all their leaves over the dry and hot summer, when again they would lose more water than they could take up.  Plants from the hotter areas of Africa tend to do this.
Bulbs are, in effect, deciduous too, except instead of dying back to a perennial or woody system, they defoliate entirely and survive in the form of swollen roots.  Most bulbs do this by growing over winter and early spring, flowering and setting seed in early summer, then dying down until the autumn rains arrive, when they start the process over again.
Others, though, do this differently, and they prefer to like dormant over spring and summer, then burst forth with their flowers in autumn, grow until the spring, then die down again for the summer.
My mother had a warm north-facing bed underneath her bedroom window which was filled with bulbs – lots of old fashioned freesias and muscari, but also big patches of three of these autumn flowering beauties.
The first of these was the clear white rain lily, Zephyranthes candida, also erroneously called an autumn crocus.  This is probably the hardiest member of its family, and is a reliable late summer flowering bulb, that reputedly flowers with the first of the autumn rains.  I am not so sure that the trigger is the arrival of rain, as I have grown this in one of the beds at the back of the section, and it has reliably flowered in late February/early March each year, despite receiving regular watering as I keep the rest of the bed alive.
The leaves are deep green and similar to thin daffodil leaves.  The flowers pop out of papery sheaths and are pure glistening white, about the size of a garden crocus.  It is a good garden plant without being extremely special.
Last year I noticed someone advertising some of the rare species and hybrids from the family on TradeMe, and took the chance to increase my meagre stock of these.  The four or five varieties I purchased are all tenderer than my garden stock so I grew them in pots in the glasshouse, thinking that I could also better control the water supply that way.
This week the first of them came out, and what a glorious surprise it was.  I have read about Z. grandiflora for years, and seen photographs of it in various books, but I had no concept of just how much bigger it was than Z. candida.
The 100mm flowers, which are a luscious pink, similar to the colour of belladonna lilies (to which they are quire closely related) are more open than Z. candida, and are held atop 100mm long scapes.  They are certainly more exuberant than their white-flowered counterparts, and a clump of them makes a fabulous sight.
There is now a range of hybrids that bulb fanciers can sometimes get access to, with yellow, orange and salmon forms all to be found, although none is readily available.  The related genus of Habranthus can also be found from specialist growers.  
By the way - you might actually call these rain lilies the true wind flowers, as that is what there botanical name means - Zephyr= wind, Anthes= flowers.

Sunday, February 09, 2014

Springing the leeks

The long and unspectacular summer has spluttered on through the past week, with showers and almost wintry conditions prevailing for much of the time.  I went to a barbecue the other evening, and we almost managed to get through the meal before it started to rain lightly.  Fortunately we were underneath  sun umbrellas  - hardly needed for sun though – and were able to stay outside for a while.
At one stage the conversation turned to planting winter vegetables and someone suggested leeks would be good to pop in now. I was a bit surprised as I always think leeks should  be planted before Christmas, especially if you are keen to grow the large leeks we are accustomed to.
My friend, though,  said she always planted later, and that she didn’t mind if they were a bit smaller than usual, as she likes the small sweet leeks that come from a later planting.  That made me think a bit, not least because I had not planted any leeks in the early summer.  So this weekend I got a bundle of field grown leeks and popped them into the garden.
Ideally leeks should go into ground that has previously been used for a fruit crop (tomatoes, capsicums, egg plants) but I am a bit short on space at the moment and I had to plant them in land I had just harvested my crop of Elephant Garlic.  I refertilised the soil because leeks and Elephant Garlic (larger and milder than usual garlic) are actually variants of the same species and I probably should have chosen a different site – except this is perfect for leeks.
I did the usual stuff for leeks – creating a small hole for the seedlings – about 20cm deep – and carefully planting the leeks into the holes.  They were well watered in, and as time goes on the hole will naturally fill itself in, ensuring the bottom portion of the leek will be white when it is harvested.
You can make a ridge about the same height, and then plant the seedlings in a trough along the top of the ridge, gradually filling it in as the plants start to grow, and that will have the same effect.
The good thing about leeks is that they are pretty much fool proof, and as such are great for the new gardener, who is probably a little unsure about what to do with the garden over winter.  We have never had any disease problems with leeks, and as long as you make sure you keep on feeding them they will grow for a few months yet.  Make sure you harvest them before the spring of course, as they will develop a woody stem as they start to put up their flower heads.

Sunday, February 02, 2014

Whipping the hebes

Among the many native plants I am fond of, the vast collection of flowering shrubs that make up the genus Hebe come top of the list.  This remarkably diverse group of nearly exclusively New Zealand shrubby equivalents of the Northern Hemisphere veronicas has evolved into a wide range of plants in Aotearoa, and fills many ecological niches in our environment.  Through in the works of hundreds of years of plant breeding and you have a valuable range of plants suitable for most gardens in one way or another.
In the heights of the mountains a particularly odd-looking group of hebes grow, with leaves almost completely absent.  These are the whipcord hebes, now known by botanists as  Leonohebe but for our purposes they can remain hebes.  Perhaps the best k own of these is the South Island species known as H. cupressioides.   Those of you familiar with Latin will know that this means “like a Cypress”, and there could hardly be a more apt description.
In a case of similar adaption to the same environmental conditions, this hebe has evolved the same tiny, adpressed leaves that conifers that live in the sub-alpine conditions that these plants live, and has ended up looking just like them rather than the closely related hebes that grow nearby.
The very small leaves – almost scale-like- grow tightly around the stems until the casual observer would not think the plant had any leaves.  This is, of course, the same adaption that the conifers have made to avoid losing too much moisture in the dessicating winds that blow almost incessantly in the mountains.
Unlike the conifers though, these plants have a wonderful show of flowers when the conditions are right. The white or light blue flowers are held at the end of the upright stems and when the season is right, can completely smother the tops of the shrubs in a haze of colour.  It seems to me that these flowers are carried with more abandon in cooler areas, and the plant does not often flower abundantly this far north, but this is still a plant well worth growing.

Sunday, January 26, 2014

On the straight and yarrow

In the past few weeks I have been reconstructing parts on my garden, and reconsidering others.  Two large plantings of Alstroemerias have been cleaned out – they were both about fifteen years old and become just a little overgrown in their beds.   I will have to think about their replacements as I have nothing in mind yet.

I have been using another area to grow-on plants as I decide whether I want them in the garden, and I think I will clean that out, plant the ones I like into other places in the garden, and set about planting a little summer flowering garden, based on the North American prairies.

As a general rule I am reluctant to get too intellectual about gardening – it is primarily a fun activity for me and I am not interested in building a garden that has a complicated set of rules about what plants should or should not be included.  I love New Zealand plants, and have many of them in the garden (some to the Head Gardeners dismay I have to say) but I would never think of planting a New Zealand-only garden, and so the same rule will apply to the prairie garden – I want to create a garden with the feel of a wilderness dryland garden rather than a botanical replication of the prairie.

There is a group of plants that will be essential for this garden – the vast daisy family, which has many representatives that revel in these sort of conditions.   Among the first of these daisies will be the relatives of the common weed yarrow, the white (usually) flowered plant found growing in wastelands on the side of the road, as well as invading lawns.  There are many beautifully coloured cousins and hybrids in this family that add a sort of wild elegance to the border at this time of the year.

Perhaps the most dramatic of these is the stately Achillea filipendulina 'Gold Plate', with the finely dissected fern-like foliage typical of the family, but with bright golden heads of flower carried about 1.5 metres tall. In this variety the foliage is grey-green, giving another contrast for the border even when it is not in flower.  This plant would be ideal as the central highlight in my garden.

Around it I would like to have one or two other varieties as well. A few years ago there was a lovely strain of seed grown plants available and I think some nurseries must have kept cutting-grown varieties from these as there are some named forms found nowhere else but New Zealand.

There are some pink and lavender forms around, but as this garden will be in the yellow/orange/red range of colours I will avoid those, and plump for ‘Terracotta’, which has flat flower heads of rich terracotta that fades to a soft yellow.  ‘Fanal’ is a good red flowered variety that will perform better if the flower heads are removed after flowering.