Sunday, May 31, 2009

Beating the blight

One of the interesting imponderables facing gardeners in the next few years is going to be the fate of the much-fancied camellia. All flowers come in and out of fashion, and the camellia has certainly had its peaks and troughs of popularity. In Victorian times the heavily doubled, and intriguingly splashed, formal types were in favour, but in the 1970s and 1980s, more relaxed forms, with plain colours predominating, became the norm.
They once again became very popular with gardeners again. Their evergreen manner and the dark glossy leaves that look so attractive even when the shrub is not in flower, made them favourites with people looking for year round value, and a more easily maintained garden.
Then along came the dreaded flower blight and everything changed again. This horribly disfiguring disease is caused by a very virulent fungus and effectively destroys the beauty of the blooms by browning them. There is no sign of any effective control yet, and those who passion is growing camellias must be throwing their hands up in frustration.
For us general gardeners, who are faced with messy camellia bushes, there are a couple of little tricks we can do to help things.
I have read other garden writers talk about extra care with hygiene being a partial solution, but frankly, I think they are dreaming. The theory is that because the disease is soil borne, if all diseased flowers are swept up from underneath the trees and deep mulch applied, the spread of the disease will be halted, and some form of control attained.
I think the advice is at best hopeful, at worst misleading. The spores can clearly move in the air, as its spread throughout New Zealand was remarkably quick, so any thought of sweeping up all the bold flowers to keep the disease at bay is just fanciful.
The answer is to plant Camellia varieties that get their flowering out of the way before the disease starts to kick in, in August and September. The best varieties to go for are the sasanquas
These are derived from a species grown in Japan for centuries, valued for its white flowers and gentle scent. It flowers from early autumn into the early winter, although other types flower later in the winter, even into early spring.
They have a more open growth habit that the more familiar Camellia japonica and hybrids, with narrower leaves and willowy growth in many cases. They make wonderful wall shrubs, when allowed to splay out in one dimension, but some of the denser growing forms also make very good hedges.
‘Yuletide’ has certainly become the most popular of the reddish forms, with compact growth and a great display of single red flowers, each filled with a great boss of golden stamen. This is a very tidy grower, and although it is not the fastest growing of the sasanquas, it still makes a great hedge.

Sunday, May 24, 2009

Going nuts

This season has been wonderful for feijoas. Our own tree has cropped well despite a fair measure of neglect, and a friend has kept our breakfast plates overflowing with enough large fruit to sink the muesli under a sea of milk. Delicious.
There has even been enough to make a few feijoa and walnut cakes. Fortunately we have also been given some fresh walnuts to use in the cake, as our small section could not harbour a walnut tree.
Two friends have given us walnuts, and the nuts could not be more different. One set of nuts are small and bullet-like – the second lot are large and easily crushed, with a large number of them filled with delicious meat.
Walnuts are among the most popular of nuts in New Zealand, and once upon a time, when gardens were all larger and people were more concerned with a higher degree of self-sufficiency, most backyards would have featured a large walnut tree. Maybe with the increased interest in home produce, we might see a swing towards growing walnuts, and other nuts, again.
The so called English walnut Juglands regia, (it comes from a wide stretch of Southern Europe and Asia but not England), is the most commonly planted walnut by a long way. It is a rapidly growing, ultimately tall tree, so some thought needs to be given to its placement. Your neighbours are not going to be too happy if you plant it along a fence line and take out all their afternoon sun!
Choose a deep, well-drained fertile site, preferably with some shelter from the worst of the spring winds, which will give the foliage a going over. If you are in a cooler area, make sure it is not planted into a frosty dell as late spring frosts will play havoc with the flowers, meaning little or no nut production.
There is some debate about whether it is important to choose a grafted tree or not. Some companies insist that seed grown trees will catch up with grafted varieties after ten years or so, while others insist that it is always best to go with a grafted form. The seed grown trees will be bigger, but they will take longer to crop and you will not be absolutely certain what the nuts will be like. On balance, I think it is best to pay the higher price and get a grafted tree. They will be quite a bit dearer, but a walnut tree is a long term investment.

Sunday, May 17, 2009

Rosemary, I love you

I was trying one of my favourite winter meals this weekend, a roast leeks and fish dish from one of Jamie Oliver’s cookbooks. It requires the use of a few herbs, so I raced out into the wild windy and watery evening to grab a few sprigs of rosemary and thyme, only to find my rosemary was an ex-rosemary.
It was my own fault.
I had planted the trailing rosemary a few years ago, on the edge of an elevated garden bed, but I had planted it near a Magnolia grandiflora, which has grown in the interim, and now completely shades the area where my rosemary should have been. A self-sown kohuhu, Pittosporum tenuifolium, with small grey scalloped leaves, has also grown in the area, so my poor old rosemary did not have a chance really.
Rosemary, Rosmarinus officianalis, is a Mediterranean plant and needs full sun and good drainage to succeed well. In the past I have found they will flourish on the edge of elevated gardens, and will even survive in dry stone walls, as along as they are well watered during their establishment period.
Once growing they should need no watering or feeding, and will only require the occasional trim to keep them tidy. They are not predated by any insects that I know of, and will prove hardy down to more frost than you will find in our area. They make a great seaside plant, as the “marinus” part of their Latin name will let you know.
They are, of course, useful plants inside the house as well. Oil of rosemary is an important ingredient on Eau de Cologne, and it is an important ingredient of numerous culinary recipes. Sprigs are said to impart a lovely flavour to barbecued meat if they are thrown on the embers.
I will replace my one soon, and will probably use an upright one this time, in a different garden. ‘Tuscan Blue’ is probably the best erect form. It has rich green foliage and deep violet-blue flowers. It makes a rigid upright form, quite narrow when young, and as the branches sprout from the base, it can be used to make an effective hedge. .
‘Lockwood de Forest’ is a prostrate form of the above variety, with the same deep flowers and dark, narrow foliage. The other common weeping form, ‘Prostrata’, has much lighter blue flowers, and lighter green foliage. It does make an interesting mat, almost assuming bonsai like growth at times. It is fabulous for use among stone walls or elevated rock gardens.
There is a pink flowered form around, but the “pink” needs to be seen through rose-coloured glasses to be satisfactory. There is also a white flowered form, but the flowers are not clean, and surely the point of rosemary is that it is blue?
Some friends in the local herb society recently gave me a copy of a small book they have produced called ‘Herbal, Green and Practical Tips’, which is a useful compendium of useful hints and remedies – I guess it is the accumulated wisdom of centuries of gardeners. I looked in it to check something I was told when a child - that rosemary made a good hair conditioner. Sure enough, there it is in the book – use rosemary for greasy hair!
The book also recommends rosemary for use with lamb and chicken (not fish I noticed!) and a few leaves in a cup of tea are said to give a pleasant taste, and also help the memory work well (if you remember to do it of course) and aid the nervous and circulatory systems.
This was a not of much use to me – I have no rosemary bush at the moment.

Sunday, May 10, 2009


One of my earliest gardening memories is gathering poppy buds with my mother. She would carefully cut each stem with a pair of scissors, selecting those that were not quite open. The stems were then brought inside and the end of each stem scorched with a candle flame. I was always intrigued by the way the black hairs on the end of the stems were quickly consumed, while the stem ends were singed. My mother told me thr flowers would keep better in water if treated this way.
Perhaps that is why I have always had a soft sport for poppies. They have a bold simplicity of form, with their (usually) single bowl-shaped flowers, and often have subdued colour clarity.
The most popular poppies are undoubtedly the Iceland Poppies. They are derived from the wild short-lived perennial species, Papaver nudicaule, which occurs naturally in the high latitudes of Europe and Northern America. They are found in, naturally, in Iceland. In the wild they are only yellow and white, but over the 250 years they have been cultivated, a wide range of colours has been developed, especially into the deep orange and pink shades.
In the garden they tend to behave like biennials, although they can be kept a live for more than one flowering season. We usually plant them out in autumn for spring flowering. They do best in well-drained soil in full sun. They look fabulous in areas where the sun can shine through the translucent petals.
There are many varieties of Iceland Poppy available as seedlings, most very similar. I usually grow the older variety ‘Artists Glory’, which has a good range of different colours, with some two toned forms. If you are constrained for space, try the ‘Wonderland’ series, which has a similar range of colours but only grows to about half the size at about 20 cm. The flowers are correspondingly smaller.
There are, of course, many other poppies, some of which hold a special place in the hearts of the general populace, while others hold special places in the hearts of serious gardeners.
The red soldiers’ poppy has come to commemorate our fallen soldiers - a wonderfully evocative floral symbol of remembrance. It is the red corn poppy, which spread across Europe as our first ancestors moved across the continent with their cereal crops. The poppy came along for the ride as a cornfield weed.
Its significance as a remembrance symbol derives from the Canadian doctor John McCrae’s evocative poem In Flanders Field, where he draws on the way the blood red poppy bloomed on the killing fields of Flanders. This so moved one woman that she campaigned to have the poppy accepted as the official symbol of remembrance for the United States, from where it spread to Commonwealth countries.
The single red soldiers’ poppy can be bought for the garden, but its descendants, the Shirley poppies, are more common. These are the result of an observant English country vicar, the Rev William Wilks, who noticed just one flower with a white rim around the edge of the petals. He took seeds from this plant and grew them in his garden at Shirley, selecting for both colour and flower form until he had singles, doubles, and intermediate forms, in colours ranging from white and pale lilac to pink and red. Following generations have also been at work on this species (P. rhoeas) and have made the flowers much larger, until they now match the largest of the Iceland Poppies

Sunday, May 03, 2009

Prickly pears

While we were walking around the Gisborne Botanical Gardens recently the Head Gardener and I came across a large cactus collection donated to the city some years ago. Much of the collection was housed in an attractive looking glasshouse, which was closed. I read that it is closed each weekend, which seems somewhat bizarre, but there you go.
There were a large number of prickly customers outside though, including some Opuntia species that were in fruit. When I pointed out the fruit to the Head Gardener, and told her my brothers and I used to eat them when we were children, she looked flabbergasted and a little horrified.
My mother had a small collection of cacti in a large built-in planter box alongside our living room window, in a warm, north-facing position. She always said it was to deter my father from coming home drunk, and as I can not ever recall him doing so, I guess it worked.
There were a couple of Opuntia species. These are the cacti with fan shaped leaves, covered with clusters of fierce spikes. One had “fish-hook” spines, each end tipped over to make extraction even more difficult. One of my uncles fell foul of this brute when he was painting our house and had to be taken to the emergency department to have the spines removed.
The other variety was similar to the species that is such a pest in the dry parts of Australia. When introduced to the large, dry expanses of the outback, these species thought they were back home in the Americas, and took off like wildfire.
Our specimen was hacked back periodically but still grew to the roofline. Each year it had an abundant display of single yellow flowers, followed by a good crop of what we called “prickly pears”.
These little fruit were covered in small prickles and needed careful handling, but they were filled with a crunchy fruit with a flavour reminiscent of water melon. They were packed with tiny black seeds. They can be used to make jellies and jams – even ice cream – but our culinary adventures were confined to eating the fruit raw.
With the trend to edible gardens that is sweeping the world, maybe we could all take up growing a crop of “prickly pears” to make up our “five a day” vegetable and fruit quota.
It is probably easier to grow some other pears though – either European or Asian pears are a lot safer to grow, and can be grown in a confined space without putting any of the family at risk!