A fossil, but very much alive – Ginkgo biloba

At the front of the Cambrian Lodge Motel in Cambridge on the main road to Hamilton, this ginkgo has been a remarkable sight for many years. Its wide spreading habit of growth belies the usual pyramidal form and may possibly be a result of having been topped and trimmed over several years earlier in its life.

At the front of the Cambrian Lodge Motel in Cambridge on the main road to Hamilton, this ginkgo has been a remarkable sight for many years. Its wide spreading habit of growth belies the usual pyramidal form and may possibly be a result of having been topped and trimmed over several years earlier in its life.

Ginkgos are remarkable trees – botanically, in the landscape and in traditional medicine. They are spectacular at this time of year with their pure golden colour and must be one of the showiest stars of autumn. I am assuming the common name of “maidenhair tree” has come about because of the resemblance of leaf shape to the common maidenhair ferns. The leaves are flat, neat little fans

I say they are remarkable botanically because they are a living fossil and in a family of one. In the kingdom of plants, tracing down from the highest order – the division of Ginkophyta – all the separate classifications descend to one solitary species, Ginkgo biloba. Mind you, it is dioecious which means that specimens are gender specific and both male and female are needed to get viable seed. It is called a living fossil, because it has been around for a length of time variously estimated between 160 and 270 million years. That is such a huge time span that it is a bit irrelevant whether the lower or upper figure is more accurate. Suffice to say, the dinosaurs may have browsed on ginkgo trees and they have outlived all their botanical relatives, surviving not only the dinosaurs but also climate changes and all diseases. That is pretty remarkable.

Ginkgo leaves have a distinctive fan shape. These are on a tree in the Gil Lumb Park in Leamington. The foliage has long been used in traditional Asian medicine, particularly for its alleged memory enhancing benefits.

Ginkgo leaves have a distinctive fan shape. These are on a tree in the Gil Lumb Park in Leamington. The foliage has long been used in traditional Asian medicine, particularly for its alleged memory enhancing benefits.

If I hadn’t looked up the tree bible, The Hillier Manual of Trees and Shrubs, I would not have realised they are classified with conifers even though they produce seed, not cones. They are at the primitive end of the evolution of conifers.

Ginkgos originated in China and have long been regarded as sacred trees. This is just as well because they are pretty much extinct in the wild so if they hadn’t been cultivated for thousands of years in Asia and hundreds of years in Europe and North America, they may have been lost to the modern world. They are long-lived and can last well past 1000 years, though not so much in this country where any tree is lucky to last past a few decades at most. In other parts of the world, the populace are not quite so chainsaw-mad and even venerate old trees. The only tree accorded that status in NZ is Tane Mahuta.

With so many ginkgos planted in the area, there are sufficient specimens of both male and female trees to get consistent crops of the nuts. While the outer casing emits a deeply unpleasant odour, the inner kernel is prized in traditional Chinese cuisine.

With so many ginkgos planted in the area, there are sufficient specimens of both male and female trees to get consistent crops of the nuts. While the outer casing emits a deeply unpleasant odour, the inner kernel is prized in traditional Chinese cuisine.

Despite the unmistakeable aroma of the fallen seed (variously described as ‘malodorous’ or smelling like vomit), once the soft casing has been removed, the seed inside is a traditional food in China and other parts of Asia. The smell is apparently in the fleshy casing, not the seed.

More interestingly, ginkgo leaves have long played a part in Chinese herbalism. The science on their effectiveness in slowing memory loss has yielded mixed results but research continues. At this stage, it is not looking as if ginkgo offers a magic bullet to reverse or even slow Alzheimers. Even now, most of our modern medications still orginate from plants. It is one reason why maintaining global bio-diversity is so important.

What started me on ginkgos was the sight of some leaves Mark had harvested and left on the back doorstep. I laughed because I knew instantly that he was curious about their memory enhancing reputation. But he forgot to bring them indoors and the wind blew them away.

Trees take a while to mature and take on their final form but the usual conical shape can be seen developing in this tree which is in Lindsay Park in Leamington

Trees take a while to mature and take on their final form but the usual conical shape can be seen developing in this tree which is in Lindsay Park in Leamington

First published in the Waikato Times and reprinted here with their permission.
All photographs courtesy of my friend Michael Jeans, Photographer, Cambridge.

Garden Lore

“When Wordsworth’s heart with pleasure filled at a crowd of golden daffodils, it’s a safe bet he didn’t see them two weeks later.”

Geoff Hamilton (1936-1996)

Kereru in the apple trees

Kereru in the apple trees

New Zealand’s native wood pigeon. the kereru

The kereru in the apple trees just outside our back door has returned. This is a seasonal appearance. It flies in every day to spend much of the afternoon munching away on the remaining apple leaves. As the trees close down for winter dormancy, the sugars concentrate in the foliage. The kereru never comes in to feed from them until late autumn or early winter but it is pretty enthusiastic now. We rarely see more than one at a time in these trees at a time although we know we have more than just the one as a regular on the property. I see they can live to be 20 years old so perhaps it is just this one that has discovered a taste treat. It is determined and will try and out-stare both humans and dogs until we get within a metre or two before it abandons ship to crash away. At 650 grams average weight, kereru do a lot of crashing at both take off and landing.

Along from the apple trees, we have planted both red and yellow guavas. They are the South American Psidium littorale, not the tropical guava. These were a nostalgic planting specifically to feed both kereru and grandchildren alike. The latter have yet to make an appearance but the kereru are appreciative.

As far as we know, our kereru stick around all year, feeding from a variety of berries, fruit, seeds, flowers and leaves. While they are usually solitary birds, we have counted up to 15 at once on a memorable occasion. Various reasons are given for the national decline in numbers but none of the experts seem to add extremely poor nest building to that list. When it comes to nests and ensuring the safety of their one, solitary offspring at a time, these birds must be contenders for the title of NZ’s worst nest builders.

First printed in the Waikato Times and reprinted here with their permission.

Plant Collector: Narcissus bulbocodium var. citrinus ‘Pandora’

Narcissus bulbocodium var. citrinus ‘Pandora’

Narcissus bulbocodium var. citrinus ‘Pandora’

Look! The first narcissi of the season – commonly known as daffodils, although the hooped petticoat varieties look somewhat different. These have just the cup with 6 very narrow, spiky petals forming the skirt. It is the pale lemon ones that flower so early. The more common, bright yellow N. bulbocodium come considerably later in the season.

The foliage is narrow, described as grassy. While sometimes recommended as a good option for naturalising in grassy meadows or on banks, we would beg to differ. It is too hard to pick the foliage and emerging flower stems, which makes it difficult to do a late autumn trim on the grass. Without that trim, the narcissi can get swamped by competing growth. We use them in the rockery and along the edges of paths or walls. They are quite happy on the side of the stony drive. Good drainage is the key – they hail from south western France, Portugal and Spain.

These dainty narcissi are like slug magnets, as you may be able to see in the photo. After being somewhat relaxed about the munching varmints in the off-season, it is a call to action before the bulk of the winter and early spring bulbs come into bloom, offering a veritable smorgasbord.

First published in the Waikato Times and reprinted here with their permission.

Fencing options for urban gardens (probably part 1 of several)

0011) In times gone by, this was the norm – a low boundary fence which allows views in while marking the territory. The owner of this house tells me her husband likes to be able to see out too. Some folk enjoy being able to chat to passers-by and like having their front garden visible to people. It is a different mind-set altogether to those who want their space to be completely enclosed. In that case privacy is sometimes only a step away from voluntary imprisonment.
0022) The plastered expanse of wall has become increasingly popular with its clean modern lines and the luxury Mediterranean look. It is usually smooth plaster applied to a concrete block construction so is not a cheap option. This one is at the end of a cul de sac where it may be safe. If you construct a wall like this in a more public position, it is like an invitation to taggers, offering a perfect blank canvas.
0033) We have admired this fence for many years, even though closer inspection shows its construction is pretty rough and ready. It is made out of by-product from some commercial kiln-firing enterprise. The rounds are in joined pairs and we wonder if they were stands for field tiles or similar. There are a lot of them, for this is a large wall. The variation in both colour and texture appeals and it is a creative use of waste material, though probably a one-off.
0044) I mentioned in Garden Lore recently the hostility and ugliness of the stark gang-headquarters style of timber fence. Even just adding some detail can break up the utility expanse of tanalised timber. Making the support pillars visible breaks this fence into panels where vertical and horizontal palings alternate. Staining it would help reduce the stark appearance. I prefer charcoal colours for their ability to meld into the landscape. Browns can get too ginger-coloured and green has so many tones you may end up with a synthetic shade which shouts rather than blends.
005 alternate5) These substantial walls also show variations on the timber fence theme. The closer fence has tried for some detail with the use of concrete block pillars and footings and the shaped top to each panel. The second fence is brave although I find the colour a little garish. Maybe it will fade. The use of over-sized round posts and the top railing add emphatic detail which lifts it above cheap utility.
0066) I photographed this in Auckland’s Mount Eden where I felt the traditional picket fence sat far more comfortably with the equally traditional villas than the newer options of solid walls closing in the properties. Here the owners have planted an inner hedge which they keep clipped. It gives additional height and privacy without the “in your face” unfriendliness of a solid wall. It is often a fallacy that major walls act as security. Once breached, they can equally give burglars free reign out of sight from passers-by.

First published in the Waikato Times and reprinted here with their permission.

Garden Lore

“How magnificent it sounds! That is the fun of writing of one’s garden: a steep bank can be a cliff, a puddle a pool, a pool a lake, bog and moraine sound as though a guide were needed to find your way across them, and yet may be covered by a sheet of the Times. My Dolomites like within the compass of my outstretched arms.”

Edward Augustus Bowles My Garden in Spring (1914)

The death spiral

The death spiral

This is not a happy tree and that is not autumn colour you are looking at. It is a slow death spiral unless we can intervene. Despite sharing the same reservations as most New Zealanders about variegated yellow conifers, we regard this one as special and wish to keep it. It is Chamaecyparis obutusa lutea nana and after about 40 years, it is a handsome, small feature tree in our rockery, not much over two metres tall.

The spiral-type pattern of the dead sections is a sign that it is a root problem and that, so far, only the part of the root system that affects those sections of the canopy is failing. If one solid section of the tree was affected, it can indicate that the tree is dying from top down and that it may be possible to cut out the infected area. But the overall patchiness shows it is dying from bottom up.

While we are increasingly reluctant to reach for the chemical arsenal, the first step here is to saturate spray for phytophthora, a varied pathogen that attacks root systems. It is a problem in vineyards and a form of it caused the potato famines in Ireland. If that fails, the last ditch attempt will be with Trichodowel – fine pieces of dowelling, each impregnated, according to the packet with “not less than 100 million Trichoderma viride spores” (who counted?). The dowels are designed to be inserted into the trunk or branch where the good spore can multiply and maybe defeat the baddies. If it was a silver blight problem, we would use these first but it is either/or because the anti-fungal spray will kill the beneficial fungi.

If it wasn’t a valued feature plant, we would let nature take its course and we would not replace it with another woody plant which may suffer the same fate.

First published in the Waikato Times and reprinted here with their permission.