Sunday, January 31, 2010

Lavender scents

I have had a bit of a surprise this summer – if “summer” is what you can call it. I had always imaged the aromatic woody herbs – lavender, rosemary, sage, thyme – would release their essential oils best on very hot days.

I had visions of strolling through dry Mediterranean landscapes, crushing these small shrubs as I wandered by, surrounded by olfactory delights.

But it seems I might have been wrong.

Most days I cycle to work past a large bed of English lavenders, lining a pedestrian crossing, and this wet, soggy and thoroughly annoying summer, the plants have more scented than I have ever noticed before.

It just seems so incongruous.

All the garden books advise planting these shrubs in a very sunny, well-drained site, but there these plants are, thriving in a soggy summer, and flowering and “scenting” very well. It is so confusing!

There are, of course, a great many different types of lavender to choose from, and perhaps it is just this one variety that is heavily scented in the rain.

Most lavenders fall into one of three distinct groups: the French lavenders, derived from Lavendula dentata; the Spanish or Italian lavenders, L. stoechas, and the “English” lavenders, (that do not actually come from England) L. angustifolia.

In general terms, the French are the largest growing varieties, with long stems and toothed leaves (hence the “dentate” part of their name). The Italian and Spanish varieties are smaller growing, and have lovely soft grey foliage. The English hybrids are usually the smallest growing varieties, with finer foliage and daintier flowers.

The French types are not planted as often as they would be if they were smaller growing, as they end up too big for most gardens. You can still buy them for hedges, but they will grow up to two metres tall.

The “stoechas” varieties are now the most numerous, and it seems there are new varieties on the market each year. You only need to grow a few of these, and have them start seeding, to quickly realise how variable they are from seed, and how easy it would be to start selecting for different flower types and growth habits.

Perhaps the best one for New Zealand conditions is the Invercargill-bred ‘Marshwood’. This has lovely deep purple flowers with extended dusky pink ‘ears’. This is a very reliable variety, and is now grown in many parts of the world. There is an even deeper form, a seedling from ‘Marshwood’, called ‘Hazel’ that is worth looking out for.

There are many different colours and shades among these plants, with green, pink and nearly-white forms popular over the past year years, and they seem to come and go at a bewildering rate. One I am sure will be around for a while is the intriguing little ‘Bee Happy’, which has violet blue flowers with pure white wings, or ears. There are others in the ‘Bee’ range – ‘Bee Bold’ has dark purple flowers topped with purple wings, while ‘Bee Sweet’ has purple flowers with light pink wings. They are cheerful additions to the ranks of easily grown shrubs.

Monday, January 25, 2010

At last - the true Geraniums

For the past couple of weeks we have been taking a look at the plants most gardeners call “geraniums”, although they are in fact members of the closely related Pelargonium genus. These are the showy succulent perennials, largely from South Africa, that grace most New Zealand gardens, usually placed in dry, sheltered areas where other most plants struggle.

There are however, many very useful plants among the true Geraniums, and they are met with much more infrequently, despite being colourful, long-lasting perennial plants.

One of the best of these is the delightful Geranium maderense. This is a slightly frost tender perennial from Madeira. It has large pinnate leaves which have a tropical feel. Each plant forms a large dense clump up to metre in height and diameter. The flowers only appear after two or three years, but the floral effect is well worth the wait.

A huge stem appears in the middle of the clump, rapidly expanding until its many branches hold hundreds of bright magenta pink flowers, each with a contrasting deep maroon eye.

Unfortunately this wonderful perennial is a short lived one – it tends to be monocarpic and after its one and only flowering, it dies. Fortunately it is a prolific seeder, and a crop of seedlings will soon appear underneath the old plant. These can easily be transplanted.

As it is a touch tender, this plant will do best in a protected but cool area – under light shade suits it well. It flourishes among the Rhododendrons, bog primulas, hostas and maples of Taranaki, where it is almost a weed at times.

Not all the species are as tall as G. maderense, and among the smaller growing forms there are many that are ideally suited for the front of a mixed border, and as ground cover in sunny areas.

One variety we have grown for many years is Geranium clarkei ‘Kashmir White’. This
plant will grow in full sun or partial shade with stems can be as tall as 50 cm. The pale flowers, which are 4-6 cm across, appear pink rather than white, because of the pink veining in the petals. There is also a purple form of this species. You will not be surprised to read it is called ‘Kashmir Purple’.

When I first stared gardening the most common of the small true geraniums was probably the “Bloody Cranesbill”, G. sanguineum, its Latin name reflecting is common name, or vice versa. Its names, apparently, have nothing to do with the colour of its flowers, which in my experience are a lurid magenta pink, but rather the red colours the leaves take in the autumn.

It is an attractive plant all year round, in or out of bloom. The foliage is usually more distinctly cut than other geraniums, giving it a delicate appearance. The typically cup-shaped flowers can come in shades of pink, magenta and white, and give one of the best bloom displays of all the geraniums, the flowers can completely hiding the foliage.

If you are sick of the once fashionable white flowers and are looking for a garden to suit the more Goth-like members of your family, G. phaeum is just the thing for you. A medium sized plant with leafy foliage, this species comes complete with nodding flat flowers in a sombre purplish-red colour – almost black enough to satisfy the most angst-ridden teenager!

It prefers shade or semi-shade where it will make a good ground cover.

Sunday, January 17, 2010

More sort ofs........

Last week I wrote about the much neglected zonal pelargoniums, or geraniums as most people call them, inspired partly by the wonderful flowering season they have been having this year. I confess I have even squirreled a few cuttings from plants I have seen growing too close to the footpath. I will undoubtedly end up with more plants than I can use, but there you go.

I have always had a fondness for ivy leaved geraniums, with their slow trailing (or climbing) growth habits making them very useful in many parts of the garden. The more vigorous varieties can be allowed to climber up a trellis – we have a passionately shaded deep red form (it is almost black actually) sliding up the outside of the glasshouse – while the less vigorous varieties can be left to feature in hanging baskets.

There are many varieties, in all the usual pelargonium shades, as well as a few with very decorative leaves. One of the best of these is the old variety L’Elegante with grey-green leaves, each with a white edge that turns pink if the plant is kept somewhat dry. It has single white flowers which bloom in clusters.

Each nursery seems to produce its own branded series of ivy leaved pelargonium, so it probably pays to buy them in flower.

Regal pelargoniums are the flashy brothers to the zonals – a bit less hardy, but with larger flowers in a wonderful range of colours.

In the inland parts of Wairarapa and Hawkes Bay these need a little cosseting – they really do not like frosts and need to be kept protected over winter – but in warmer areas, and especially coastal areas they thrive, giving generously of their abundant flowers through summer.

These almost shrub like plants have been derived from strains that were originally predominantly lilac and purple, and were taller and stragglier in growth. Sometimes you will see a variety like this in an older garden, usually growing fairly wild.

Hybridisers have got to work on them improving the growth habits, and greatly improving the flowers. Today it is possible to find straight colours in almost all shades of red, pink and purple, and in many cases the flowers are blotched or feathered with wonderfully contrasting colours.

These guys need similar conditions to the zonals – good drainage, plenty of water during the growing season, and the occasional tidy up to keep them in shape. Apart from that there are few problems growing these beauties.

Sunday, January 10, 2010

Geraniums- well, sort of....

Some plants just do not get the respect they deserve. Perhaps they are too easily grown, and maybe they are too closely associated with working class gardens, but some plants are never given the credit they deserve, and are not planted often enough nor thoughtfully enough in our gardens.

Perhaps the best example of that is the poorly regarded zonal pelargonium, more usually known as the bedding geranium. This free flowering, summer blooming succulent-stemmed shrub is very popular in many parts of the world, but here is relegated to municipal bedding schemes and the like.

It  is a travesty as this wonderful plant has any amount of colour, it is drought and wind hardy –not so keen on frosts of course- and is as reliable as anything through the summer. In some more northern areas of the country rust can be a problem, forming on the undersides of the leaves, but this far south it is nowhere near as bad a problem, and zonal pelargoniums are unlikely to be bothered by too many diseases.

There are many thousands of different kinds of this adaptable and versatile plant, some grown for their colourful leaves –the “zonal” in their name refers to their leaf markings – others for their brightly coloured flowers, while yet others are treasured for their exquisitely shaped flowers.
Perhaps the most commonly seen forms today are the seed raised varieties offered for sale in garden centres and supermarkets. These are raised from very dear hybrid seed, and have been developed overseas for the potted plant trade. In most of Europe and America, these plants are largely grown to be planted out for a season then discarded. Traditionally the bright red forms are the most popular – often planted out with white petunias and blue lobelias to give a very patriotic garden - but the hot pinks are also very popular today.

One colour that has been taken up with fervour by some local councils is the “orange” strain. This is not orange really, but is an orange-ish form of scarlet, and is very effective in the garden. I have seen it bedded out with greenish Nicotiana plants, and the beds work very well. This would also work a treat if you had a terracotta planter or wall to work with.

Just because these are raised from seed does not mean they cannot be kept going from cuttings. Most of you will know that these plants are ridiculously easy to strike. I just snap a stem at a node, and leave it in a shady place for a few hours. This allows the cut area to form a little callous, which stops it from rotting before it can root. Then I just pop the cuttings into a sharp potting mix – I usually add some pumice to a standard mix – and watered well. They will usually have rooted after a week or two.

I was recently visiting as gardening friend, who always has a wonderful collection of unusual and choice plants to see, and she gave me a cutting of her scarlet red rosebud form, which is now happily setting roots in the glasshouse. My favourite among these, though, is the eye-catching “Apple Blossom Rosebud”, which has extremely full flowers which have a greenish centre, white petals and bright pink edges.

Monday, January 04, 2010

Those Peruvians again

A bit of a break over Christmas and the New Year saw me wandering the streets, taking my early morning constitutional, peeking over the tops of fences as always, seeing what is happening in other people’s gardens.

One thing that stood out was the number of gardens with a mix of old and new Peruvians splashed around the garden - Peruvian lilies that is. These are Alstroemerias, named after the Swedish botanist Baron Klas von Alstroemer who collected seeds on a trip to Spain in 1753. They were from plants collected by Spanish explorers in South America, and must have excited him with their bright, almost gaudy, flowers, and their very tough perennial nature.

My first experience with these flamboyant lilies was in my grandparents’ garden, where plants threaded their way through some of the abandoned beds. These large island beds, once home to big collections of perennials, had been allowed to revert to shrubberies, but various very hardy perennials remained. The ones I remember best were orange to gold Alstroemeria, as they had colonised the beds and gave a bright display each Christmas.

There are about fifty species of Alstroemeria in South America, in two broad groups – a summer growing cluster of species from Brazil, and a winter growing group based around eastern Brazil. My grandparents’ flowers would have been forms of the Chilean species, A. aurantiaca which has bright yellow flowers, usually spotted with maroon. It grows very readily in any free draining soil – perhaps too readily actually, as it becomes overcrowded quite quickly, and then sets out for pastures new. It is not a great problem to control, but it can be a bit of a pain.

I also remember the intriguing species, A. pulchella (also called A. psittacina) which has a similar growth habit to the foregoing, but also has the most intriguing narrow trumpet shaped flowers, in green and red. It looks very entrancing, but this is far too energetic for anything other than very hard conditions. Given a free run, this will – well, run freely.

I had quite a battle with this for a couple of years in a free draining, elevated garden, but did eventually get it under control. This weekend I noticed it in a town garden, growing in quite dense shade under some trees, where it had wandered a little but did seem to be largely under control.

These species, and hybrids derived from them, were very popular cut flowers. I remember my grandmother filling vases with these bright lily-like gems. They lasted well in water and brightened up the house considerably.

For commercial growers they were not a great crop as they had a restricted flowering season, until the 1980s, when a group of America plant breeders decided to take matters in hand, and crossed the winter flowering types with the summer flowering forms, and succeeded in establishing a totally new type of Alstroemeria which was more or less evergreen, and which flowered for long periods each year.

Further breeders saw the potential for using these plants in the garden and in the potted plant trade, and concentrated on reducing the stature of the plants and removing the aggressive spreading trait. The first of these new varieties started appearing perhaps fifteen years ago, with willowy growth and smallish flowers. Work has continued and now there is a great range of smaller growing plants with stocky growth habits and relatively large flowers. I have some clumps that are ten years old and only about a metre across. I cannot imagine a summer garden without a display of these South American beauties.