Sunday, June 30, 2013

Mid-winter ramblings

For the past couple of weeks I have been on annual leave, having what I believe young people call a ‘staycation’, when you are on leave but remain at home.  Mid-winter is certainly an interesting time of year to be on leave, and the days have alternated between cloudy and cold, and frosty and fine – and cold.
On one of the finer days I swept the dust off my old golf clubs, packed them in the back of the car and went out east, to gently hack my way around the Castlepoint Golf Club at Whakataki. It was an interesting round, where I was accompanied by the sounds of yarding from a neighbouring farm, with the usual sound effects from a mob of sheep, a pack of barking dogs, and the whistles and shouts of the farmer.
On the side of nature, I was also delighted to have the company of a large troop of tui as I moved from hole to hole.  Over the years the golf club must have thought of winter feed for honey gatherers as they planted out the fairways and byways of the course, and the tui were greedily sipping from the red flowered gum trees that were scattered throughout the course.
The most common of the red flowering gums, and by far the prettiest, is the Western Australian native E. ficifolia, now called Corymbia ficifolia by botanists, if not by gardeners.  This is a small but densely-growing tree with large racemes of tightly growing flowers, and at its best in the summer, is a vibrantly dramatic tree, sometimes confused with pohutukawa.
It is slightly frost tender, but will grow in inland Wairarapa as long as it is given some protection in the first few years of its life – there is a spectacular tree in Opaki Road, nest to the Mormon church. In warmer areas, such as on hills or nearer the coast, it makes a wonderful small tree, and is frequently planted as a street tree in towns further north.
It is easily raised from seed, but is very hard to graft, and therein lies a slight problem. This tree does not come true from seed, so there is a risk in planting out a seedling – it may not give the wonderful orange/red colour the gardener looks for.  The flowers can be paler, right through to soft pinks, and even pure white.  A few years ago I ran along an avenue of these trees on the other coast, and there was no unanimity at all – no two trees seemed the same colour.
The winter flowering species, which is so useful at supplying feed for honey-eating birds, glories in the names of Eucalyptus leucoxylon ‘Rosea’, and is a form of a South Australian species, known as Yellow Gum in its homeland, although it also has a number of other common names.   It grows in a more open manner than E. ficifolia, displaying its light coloured bark.  Although the species is variable as to flower colour, the bright red form commonly grown for ornamental purposes is generally fairly true to colour.  Having said that, I have to say that it is not uncommon for pink forms to appear when these trees are grown from seed.

This tree is slightly bigger than E. ficifolia, especially when grown in a position sheltered from the worst of the wind – conditions which do not apply to the Castlepoint Golf Club I have to say.  That size, and the propensity of gum trees to shed branches, probably means that this tree is not really suitable for growing in smaller sections, but larger gardens can easily cope with one of these.
And the golf?  Well, I enjoyed a walk in the country, and sounds of a working farm coupled with then bird song in the bright clear skies made for an enjoyable morning. The less said about the golf, the better.

Sunday, June 23, 2013

Schlumbergia - what?

Among our favourite plants there are many with such ugly names that we prefer to call them by their old ones.  The fabulous winter flowering iris is known by most people as Iris stylosa, surely a much classier name than the now correct, Iris unguicularis.  Similarly, the winter flowering cactus that I always knew as Zygocactus has now been renamed with the un-euphonious Schlumbergia. I think I’ll stick with the old name, or perhaps use a common name.
In the Northern Hemisphere these plants are known as Christmas Cactus, rather obviously because they flower in the middle of winter.  Here in New Zealand they are sometimes called Crab Cactus, from their unusual flower shape, or more commonly, chain cactus (although there are other cactus known by that name) or inch cactus, from the fact that the leaflets grow an inch at a time. 
As a matter of botanical interest, these “leaflets” are actually the flattened branches of the plant – it does not actually make any leaves, but carries out photosynthesis through the branches.
These wonderful plants, given their “new” name in the 1890s to commemorate Frederic Schlumberger, a French collector of cacti, but it never became popular, and to be honest, most modern nurseries do not use it now either. 
Although these are true cactus plants, they are not desert plants as you might expect - they originate from the jungles of Brazil, where they grow as epiphytes on the trunks of large trees.
 I am sure that most people will be familiar with these cute little winter flowering plants, usually from ones that have been handed around among the family, as they are so easy to propagate.  Once they have finished flowering, the “leaflets” can be detached and popped into potting mix where they will quickly grow new roots and start all over. 
I have a small collection of these in the glasshouse where they can happily sit on a bench until they start to flower.  The most magnificent of these is a lovely light pink flowered form, which I started some years ago as a cutting from a plant that a workmate’s mother brought in to work for us to share the flowering.  I do not know that she thought we would also pinch one or two leaves!
The other plants I have are some I bought a few years ago from a nursery, and they were very modern ones with quite different colours.  These are very popular potted plants in the northern hemisphere, as you can imagine for a plant that flowers at Christmas, and breeders have got to work on them, expanding their range from the older forms which tended to be in the cerise pink range.  I have to say that these new ones, which have orange, bright red and even yellow-ish, have not been as vigorous as the light pink form but they are still very attractive.
As you would expect from an epiphyte (a plant that lives attached to another) these guys need really good drainage.  I think you could probably grow these in an orchid potting mix but I have just used a standard mix with some orchid mix added to it, about 60/40. That does not mean they like to dry out – they do not, and it is important to keep a steady supply of water.  If allowed to become too dry they will quickly withdraw water from the leaves which will shrivel.
 If you want them to do well it pays to give them some food every once in a while – I just sprinkle slow release pellets on the surface and it does the job well.  They prefer semi-shaded conditions, as you would expect from a jungle plant, and the leaves can easily burn if left in full sun.  If you have a really warm spot, you could even try growing them on the branches of a tree.

Sunday, June 09, 2013

Pitching in

Sometimes my two jobs interconnect in interesting ways, and this week gave a great example.  A local landscaper came in to see whether I could tell him about the sort of plants that were in use in the 1920s, as a client wants to re-establish an authentic garden around a beautiful workingman’s cottage from that era.
Interestingly, his client wants to use camellias, natives and evergreen Magnolias to supplement to laurel hedge which has already been planted.  Luckily, we have an old Robinsons catalogue from the 1920s at work, and I was able to show him that the wonderful Magnolia grandiflora¸ with its large bay-like leaves and bowl-shaped scented flowers was a favourite in the 1920s, and that there were a few old Camellia varieties around too, although there were none in the catalogue that were commonly grown now.
It was in the native tree and shrubs area that things have changed the most, with the 1920s catalogue being very sparse on varieties that we would think of as commonplace.  There were no Hebes or Coprosmas, and even very few Pittosporums.
This was a little surprising as Laurie Robinson became well-known a little later on as one of the most ardent garden fans of native ornamentals,  and as the introducer of quite a number of variegated forms of some of the shrubby Pittosporum species, especially tarata or lemonwood,  P. eugenioides  and silver matipo P. tenuifolium.
Robinson’s nursery, no longer in family ownership, continues to grow new forms of these popular native shrubs, and in the past year or so has released two new dwarf forms of P. tenuifolium. Over the past few years a number of different dwarf forms have been released in New Zealand, including a lovely silvery/green leaved form from Clareville Nursery called ‘Elfin’, which we have in the front garden.  They all share a naturally compact growing habit, with the ability to be clipped to be kept under control. 
Perhaps the best known of these is ‘Golf Ball’, a fast-growing dwarf shrub that can easily be kept to about 30 cm high with a similar width.  These are quite often used as a replacement for  box hedging, having a lighter look while being just as easily kept under control.  A few years ago the nursery industry was promoting the use of some Hebe varieties for formal hedges, but this makes a much better choice.
Recently two new coloured forms have become available from Robinsons, and a few other selected nurseries – a golden form and a silver one, called, you will not be surprised to read, ‘Golden Ball’ and ‘Silver Ball’. As you would expect, these varieties have bright glossy foliage, and form naturally rounded shapes, with foliage of golden and silver hues respectively.
I have been intrigued by another relatively new selection, a semi-dwarf form called ‘Reflections’.  This selection I immediately noticed in the nursery stocks as it has a very tidy form with clean high gloss foliage and striking colour. The small leaves are green with a curiously wavy edge, coloured yellow on the central rib and veins.  As if that was not enough, the stems are red and the new growth is right creamy-yellow.  This makes a nice com pact growth, perhaps a little more vigorous than the truly dwarf forms, but also much more compact that the willowy larger forms.
Like all Pittosporums, you need to be a little bit careful about insect infestation, especially the pesky little native psyllid which can pucker the leaves of left unchecked.  A quick spray with an insecticide will soon sort the problem out.

Sunday, June 02, 2013

I had a special treat during the past week.  A regular reader of this column rang me to say she had a special present for me from her late mother’s garden – a big pot filled with oxalis.
I know most of you will be appalled at the idea of such a gift, and anyone who has struggled with any of the few pestiferous members of this widespread family of bulbs will throw their hands up in horror at the thought of a gift of such pernicious, unwanted plants.
But those of you who are fans of small bulbs will have shared my excitement at the offer, especially as it was a pot of the intriguing O. versicolor the creatively coloured little plant with barbers’ pole flowers.  This little charmer has a slightly different habit of growth to most species as it forms a very low-growing sub-shrub with almost woody stems, only growing a few centimetres tall.  At this time of the year their flowers are in evidence, and what funny little flowers they are.  The plant produces crimson striped, funnel shaped buds like tiny striped old fashioned barbers poles.  They open to reveal pretty white cup-shaped flowers with crimson margins.   
We grew this plant years ago in a warm garden in front of one of the glasshouses in the nursery, in a bed where one of our sons grew his miniature roses, and it flourished, which gives a good indication as to the sort of conditions it requires – warm soil, a sunny open site, and a bit of watering over the summer.  It is reportedly half hardy but it coped with anything our climate could throw at it.  And it did not spread at all!
I have a bit of a thing about the whole group of these lovely little bulbs and have a number of pots growing in full sun underneath my office window, many of whom have been in flower over the past few weeks.
I think my favourite of these might be the delightful South African species, O.  massoniana.  This is a strong growing and very free flowering form, ideally suited for growing in containers.   It has the most amazingly coloured flowers – sometimes called ‘bright orange’, but really more of a warm, light terracotta colour with bright golden centres.   Unusually for Oxalis, this species can be propagated from cuttings of the tree-like shoots.  I find this one is not as strongly-growing as some of the other species I grow, but it is startlingly beautiful when in flower in its terracotta pot.
The various forms of O. pupurpea that I grow are now just slightly past their best.  This is wildly variable South American species, and is grown for its attractive winter flowering habit, and their attractive cut foliage.  There are a number of forms available in New Zealand, and an even wider range on sale overseas. 
Among those I grow, the one I like most is a deep purple foliaged variety which I have seen described as ‘Nigrescens’.  Naming of these plants can be confusing as nurseries have confused similar looking types, and it may be possible that it is the same variety grown in the rest of the world as ‘Garnet’. The deeply coloured, clover-shaped leaves are wonderfully offset the glowing pink flowers.  These flowers are very difficult to photograph effectively as they have a shiny gloss and the flowers always appear lighter in photographs than they do in the garden.
I grow two other forms of O. purpurea,  both having (oddly enough) green leaves; one with glowing white flowers, the other with the same shining pink flowers of the dark-leaved variety.  There are yellow and cream forms of this species too, but I have never seen them on offer in New Zealand.

This species increases very well in the pots, and, even though there are plenty of species I would happily plant in the garden,  I think I would be hesitant to plant any of these varieties in light well-drained soil as they might get a little too territorially ambitious and could multiply a little too quickly.