Sunday, February 19, 2012


It is one of the unwritten rules of life (and of gardening) that the grass is always greener on the other side of the fence.  That maxim manifests itself in some very uncomfortable ways in our private lives, but it also causes pain in the garden.  I am sure Aucklanders, who can grow an incredible range of plants, are upset that many cold-requiring plants will not flourish there.  I have seen the saddest flowering cherries and hardy Rhododendrons sulking away in Auckland gardens, when far more appropriate plants would grow much better.
In reverse, those who garden in the far south would love to be able to grow many of the subtropical plants that Aucklanders take for granted, willingly swapping their swedes and turnips for some bougainvilleas and orchids growing in the garden.
We are sort of stuck in the middle here.  Some plants will not grow because our climate is not cold enough – I despair of ever successfully flowering that doyen of Fritillaries, Fritillaria imperialis despite many attempts – and our frosts mean we have to be very careful about providing any tender plants with special shelter.
For my own part, there is one group of plants I would love to be able to grow with the ease that those further north can – the shrubby Hibiscus.  Whenever we go on a summer break to northern climes I rush around with my camera, snapping the glorious silken flowers these flamboyant plants bear each year, insanely jealous, recognising that growing them around my place is just a pipedream.  They are very frost tender and in Wairarapa they need to be placed against a north-facing wall, preferably in full sun, and in well-drained soil.  None of the many varieties can cope with poor drainage, so clay soils are out too.  If you are stuck with sticky soil, and you have a warm spot for one of these beauties, I think it probably pays to invest in a nice big pot and some free-draining potting mix.
We took this step about ten years ago, when one of the boys became interested in growing some ‘indoor’ Hibiscus – they are sold that way but they will be temporary Hibiscus if grown inside for very long.   We bought a couple of these small flowered hybrids and potted them into large earthenware containers on the patio in an east-facing spot.  They did very well for the first few years, but their performance has fallen away – the yellow one is very spindly and the red one has gone to the great garden in the sky.
To grow Hibiscus successfully in pots you need to start feeding them as once they are established, as Hibiscus are hungry feeders.  The easiest way to provide them with nourishment is a good application of some slow release tree and shrub fertiliser in early summer. Hibiscus only flower on new wood so it is good to clean out the old branches each winter and let the plant renew itself.  You can be tough with the pruning – if the plants are starting to get a bit leggy and woody you can cut them back very hard.  Within a year they will have bounced back with a new framework of growth of and more crops of flowers.  Most varieties branch near to ground level and make attractively thick growth.  If you have a mind to, Hibiscus can be trained to make wonderful espaliered shrubs, an  especially good way to grow them in our climate as they are well suited to growing up under the eaves of a north-facing wall.

Sunday, February 12, 2012

Lapageria up close

This crazy weather has been driving us all mad – even the usually reliable kick start to hotter weather – the return of children to school – has not brought any relief from the dull and cool weather of this so-called summer. Plants are confused too.  I have two types of spring flowering irises that seem to think spring has returned and have put out a few flowers, and Magnolias and Michelias have also been fooled into throwing a few blooms.
Thankfully, a few plants have been able to thrive over the season and have provided their usual generous display of flowers.  One that has impressed me this year is the neighbour’s brightly coloured Bouganvillea, which is clambering over a north facing wall of her house, in a very warm and dry spot. 
These South American plants come from really warm climates – more tropical than subtropical – and need as warm a spot as possible in our climate, away from any frosts, but at the same time sheltered from the worst of the winds.  Ideally, a north-facing wall under the eaves of the house would be the right place.
They are not fussy as to soil, but will not thrive if the drainage is poor.  Remember that soil alongside houses can be quite dry and also thin, so a good application of some humus as a soil conditioner is a good idea.  Newly planted Bougainvilleas need careful watering, with care taken to ensure they do not dry out, but once they have got their feet well and truly into the bed, they will happily thrive with next to no water.
You need to be a bit careful with feeding these beauties though – they do not mind some occasionally, but make sure you do not use any formulation high in nitrogen as that will stimulate leaf growth at the expense of flowers.  It can also cause the plant to go crazy, with long whippy growths that will need careful pruning.
In Wairarapa we are a little restricted to the types we can grow.  The bright crimson ‘Scarlet O’Hara’ and the slightly lurid purple ‘Magnifica Traillii’ are the most vigorous and hardiest varieties for our climate, and are certainly the ones I have seen growing best around here. The more subtly coloured Hawaiian varieties are nowhere near as hardy.  There are also some dwarf varieties, suggested as being suitable for containers, but I have not seem them in any local gardens.
As Bougainvilleas can make a lot of growth over the season, and because they are actually clambering shrubs rather than true climbers, they need to be pruned carefully.  They flower on new wood and can be pruned back quite hard during winter and will bounce back to bloom again the following summer. As a general guide, you can cut back the stems that have flowered to within 5cm of the older wood.   Over the summer just keep an eye on any watery shoots appearing near the base of the plant and remove them.  When doing any pruning, don’t forget these plants do not twine to hold onto the plants they grow over, they grab them with the harsh thorns that line the stems, thorns that are just as happy to grab at the gardener.
If you are looking for a colourful climber, but do not have a hot north facing wall but rather a cool south facing wall, another South American could be the one you are looking for – the luxuriant Chilean Bellflower, Lapageria rosea.
These are evergreen climbers from the cool temperate forests of Chile, and like most climbers, they prefer a situation where their heads are in the sun but their feet are in the cool of the forest floor litter.  Being forest dwellers, they will take colder temperatures but they cannot stand any frost. They have a flush of flowers any time from now until later in autumn, but they have flowers most of the time. And what flowers they are!  Large bell-shaped flowers that have such a heavy texture as to appear almost wax-like, they take weeks to fully open, and then stay on the plant for many more. 
They are generally a rosy red, as you will have worked out, but the flowers usually have a subtle checkered pattern over them, so they look even more intriguing up close.  There are white forms too, which seem to have an even thicker texture.
These are hard to find at the garden centre but I know some local nurseries stock them.  They are never cheap because they are a nurseryman’s nightmare.  They are difficult to grow from seed, as you need two different clones for the flowers to set seed, then they take many years before they are sellable as they are very slow to get under way.  As if that was not enough, snails love them and seem to be able to sniff out a new shoot from a mile away, and quickly (at least as quickly as a snail can) get over to eat them.
I have a couple of plants growing along a south facing wall – a red and a white.  I hand pollinate them each year and get seed about one year in three, and then lose about a third of plants in the glasshouse.  I am not trying to pout you off growing one of these – I think they are one of the choicest of all climbing plants, and if you have got a south facing wall with a cool root run, you should try and hunt one out.  They are very long lived, and apart from the snails do not seem to get any pests.  And even better – they do not seem to be badly affected by a bad string of summer weather.

Monday, February 06, 2012

We have interesting discussions in our family about the role ‘nature’ and ‘nurture’ play in shaping our personalities.  On the one had we have the geneticist son, on the other the teacher Mum, each arguing their corner, until finally agreeing that both have a part to play even if they do not agree on the ratio.
This argument is especially interesting at the moment as our younger son has re-developed an interest in gardening now he is established in his Wellington flat.  He had gardens in the nursery, filled with miniature roses, and a small garden here which is nominally his although he has never done any work on it.  Now he is settled in a flat his innate (or nurtured, depending on where you sit on that debate) love of gardening has come to the fore and he has made his first real gardens.
Interestingly, he has planted lots of colourful annuals, including bedding dahlias, petunias, Livingstone daisies and marigolds, despite saying he saw far too many of them as he grew up helping in the bedding plant nursery we owned.
But he has also got interested in succulents, which I guess is only to be expected as it where so many of us find our interest in gardening first stimulated.  I still have a pot of a small Aloe species that came to my from my grandparent’s sunroom, via my parents patio.  I think it is Aloe aristata, a species that was once very common as a pot plant, mainly because it was so easy to keep going.  Just pop it in a well lit area and it will flourish, eventually sending up a 30 cm tall stalk of pinkish-red tubular flowers.  Over time the mother plant will form little offspring around her bas and will eventually develop a nice clump of dark green, tight leaved rosettes. 
There are so many different succulent plants, with an almost infinite number of different hybrids that it may pay us to define exactly what we mean.  Generally speaking, succulents are regarded as being plants that in the wild grow in arid regions, and have developed water retention tricks to help survive sustained dry periods.  They usually store water in their leaves, although some do so in their stems, and a few have evolved to do it in their roots.  Many of them have also developed silver foliage as a way of combating excessive heat.
Many can be grown as pot plants, and they are good plants for beginner gardeners to start with as they will forgive the errant waterer.  On the other hand, of course they do not like too much water, so will quickly die of kept damp.  In the garden they can provide a very useful counterpoint to other foliage colours, and they are well adapted to growing in those difficult warm and dry spots near houses or on banks.
The most common of these are the Echeveria species and hybrids, part of a group of over 150 species native to the Americas, from Texas to Argentina.  The leaves, which are usually silver, form symmetrical rosettes either sitting on the ground or at the end of long stems. Some types make multi-stemmed shrubs growing to a metre tall.  They can withstand long periods of drought and will grow in a variety of garden situation, but for or really intense colour they prefer to be in a well drained position with plenty of sun and air movement and regular water.  The most commonly-grown forms are the smaller growing silver leaves species that are used for edging in dry conditions. They generally flower with a spike of orange/yellow flowers in early summer.