Article 52 – ‘Shattered and cracked’

When preparing for teaching assignments a few trees needed for display are readied, foliage and trunk/s are cleaned as are the ceramic pots and any unwanted residue (alkaline scale) is removed. It is the same practice one would undertake if exhibiting bonsai at a show, because presentation is everything students can see the real tree/s in person, which has more impact as opposed to on-screen pictures.

Inspecting the pots containing trees, one a blue rectangular pot made in Japan when picked up simply fell apart, the damage is severe and yes it could be repaired using a two part slow curing epoxy resin, which according to the manufacturers (Loctite) has “special formulated materials that are great to bond and repair plastic, metal and concrete or surfaces exposed to water.” But how does epoxy resin fare when exposed to extreme temperature differences that is the question. If this pot were to be repaired it could only be used for plants from temperate zones often referred to as ‘indoor bonsai’, that can survive quite happily out side in the summer months, but not during the winter as the chances are the pot may not survive.

Japanese pot
Japanese pot repaired

Another pot subjected to winter conditions had three hair-line cracks, hence the tree was removed and replanted in another container and the cracked pot was cleaned, on further inspection the three cracks ran from the rim down into the middle of the pot’s base both on the outside and inside of the pot. This blue green glazed ceramic pot is/was not expensive by any means, it is a cheap Chinese pot mass produced as one can tell from the pot’s rough underside. But what is attractive about it is the shape – a feminine shallow oval befitting an informal upright (Moyogi) or literati (Bungin) style and for this reason alone it was decided to ascertain if it could be saved.

Using a Dremel with a fine cutting wheel the cracks were gouged out halfway into the pot’s surface on the inside and the base only, the ceramic outside was not touched because it would have ruined the overall appearance. The glue used for the repair was the same as used for the Japanese pot (slow curing two-part epoxy resin Loctite 60 min) and for the moment it seems to have solved the problem. The pot and can still be used, but it is doubtful that it can withstand another winter moreover, neither of them can be used for public display.

Repaired pot

To answer the question of why the cracks appeared some detective work is required, being a mass produced pot from a mould where the clay is forced in, dried then fired is a relatively cheap and cost effective way of mass production. But if the clay has not been properly formed, bonding defects within the structure go undetected. The clay has to be worked and kneaded many times to make it malleable and durable before it as ready to be formed into its intended shape. Many years ago before the advent of technological automation, clay preparation or kneading was done by highly skilled people who knew instinctively when the clay was ready, which was then given to the potter.

Mass produced pots or containers sadly lack the required amount of kneading whereas, with hand-made pots this crucial stage of preparation is completed. The firing process is also a critical factor, in China the average temperature is approximately 1260 degrees C and the fired ware is referred to as ‘biscuit’, in Japan firing temperatures are higher 1305 to 1800℃, but much depends on what type of ceramics are being made hence, temperatures are adjusted.

In the case of the repaired Chinese pot, the overall structure has gradually weakened through time due to the elements and because it houses a tree, the soil medium is always moist. When the weather turns cold the moisture particles begin to freeze and expand causing hair-line cracks to form. Did this problem (a) originate when the clay was being formed – Kneaded (b) is it due to the onslaught of winter conditions or (c); the degradation of the clay’s properties over time, arguably it is all of these factors.

Generally speaking Chinese mass produced pots are relatively inexpensive but their hand made are not, Japanese mass produced pots are slightly dearer and of better quality and their hand made pots have a higher retail value. Hand made pots designed by individual artists can command very high prices as their work is of high quality and usually made to order for example, a Tokoname made bowl size: approx. 48 x 48 x 10 cm by the Japanese artist Reiko will lighten your bank balance by 625€.

Vintage Reiko bowl 48x48x10 cm
age estimated 50 to 80 years

However, this is not to say that the more expensive pots are not infallible, because they are; quite a few pots which have been in our possession since the 1970s and are of good quality have succumbed to the ravages of winter. Perhaps the question is; do quality bonsai pots have a life-time guarantee? – probably not. Until next time BW, Nik.

N.B. If you are interested is seeing how a hand-made rectangular pot is constructed, here is a suggested link:

https://www.youtube.com/watch?v=zwRCdTCHjNQ web site http://www.greg-ceramics.com

Article 51 – ‘Peat! the hue and cry’

Introduction Evidence indicates that the use of peat also known as turf dates back to Roman times where it was used for domestic purposes – heating and cooking and in the 7th century continued to play a significant economic role in countries where trees were scarce; for example, Ireland, Scotland, the Netherlands and Estonia.

Peat is the formation of plant material that has not fully decayed in acidic or anaerobic conditions, it is comprised of wetland vegetation, bog plants, mosses, sedges, and shrubs. Peat as it forms holds water, which slowly creates wetter conditions allowing the area of wetland to become more extensive. Peat harvested usually in blocks (briquettes) is left to dry prior to being used and in some countries it is used today on an industrial scale to generate electricity; elsewhere peat is mainly used in horticultural applications.

Peat harvesting

The hue and cry – Peat is unique to natural areas called mires, bogs, moors or muskegs, which cover approximately 3% of the global land surface that are highly significant to global efforts in combating climate change. According to environment correspondent Matt McGrath “Peat Is the most efficient carbon sink on the planet, because peatland plants capture carbon dioxide (CO2) naturally released from the peat, maintaining an equilibrium.” Meaning that the carbon stays in the bog, locked away from the atmosphere, but it takes thousands of years for peatlands to develop.

In the UK there has been a huge drive by the government’s Department for Environment, Food & Rural Affairs (Defra) to phase out the use of peat by both amateur and professional gardeners their argument is as follows:

“When we mine peat for gardening we unlock those reserves of stored carbon and three things then happen:

1. A peat bog is drained prior to mining. It immediately starts emitting greenhouse gases. After mining, the remaining peat continues to release carbon dioxide and methane into the atmosphere

2. The carbon in peat, when spread on a field or garden, quickly turns into carbon dioxide, adding to greenhouse gas levels

3. The unique biodiversity of peat bogs is lost. Rare birds, butterflies, dragonflies and plants disappear. It is much harder to restore a peat bog than to replant a forest.”

In 2011, the UK government set voluntary targets to end sales of peat-based compost for domestic use by 2020, Natural Environment Minister Richard Benyon stated that “The horticultural industry has made real progress in reducing peat use, but I want to see peat eliminated from the amateur gardener market by 2020”. In a letter to Environment secretary George Eustace, signed by TV gardeners Alan Titchmarsh, Kate Bradbury and James Wong, “this has been an abject failure.”

Others joining the ‘Hue and cry’ are a few garden centres including B&Q and the Blue Diamond group of garden centres who sated they were committed to phasing out peat but gave no date as to when. Asda, Lidl and others said they had targets to reduce peat sales but not yet to end them, Wyvale Garden Centres, Morrisons and Sainsbury’s have yet to respond to the survey.

Nonetheless, gardeners love peat because it delivers superb results in gardening, but some argue that peat is not the only way to get organic matter into soil, and it’s not even the best way; so why is it making a comeback? Because it’s cheap peat bogs are cheap to buy – cheaper than farmland. You drain them, dig out the peat, put it in a bag and it’s ready to sell. Nothing sustainable can compete with peat on price, so it enjoys fat profit margins. Profit margins that the above mentioned garden centres will not relinquish; does the word hypocrisy spring to mind here.

But is there an alternative to peat? – Carbon Gold was created by Craig Sams, founder of Green & Blacks Chocolate, in 2007 as an organic, peat-free planting aid for the retail sector. The company has created composts that mimic the properties of peat. Peat is a blend of black carbon and lignin the fibrous woody matter, whereas black carbon is made by using charcoal making techniques that convert woody materials into pure horticultural carbon or ‘biochar’.

According to a Sams spokesperson, “We blend it with lignin-rich woody material such as coir from coconut husks, to reproduce the profile of peat.” “It works as well as peat in the garden and it stays there much longer, the carbon in biochar remains for centuries and is porous, so it represents a long-term investment in improved soil fertility.” The Sams spokesperson added that “Commercial organic growers, who are looking for a high-performing peat-free alternative, are adopting it on an increasing scale.”

But carbon gold is expensive over 23€ for 20kg and this does not include the cost of delivery, much more than the price of peat – the above cost may seem trivial but much depends on the amount required. Finland is the world’s leading manufacturer of peat supplies and according to recent reports, said Finnish government is now looking at ways to reduce its peat consumption – but at what cost and to whom? Moreover, since the present pandemic (C19) took hold unemployment has risen prices have sky-rocketed as products have diminished, hence 30 million new gardeners have joined the horticulture brigade and the numbers are increasing.

Perhaps peat harvesting or mining will eventually be phased out, but there still remains many arguments and debates on this issue both for and against. Taiga Bonzai’s policy is not to get involved in controversy, but to bring to our readers attention issues that concern all aspects of horticulture including the husbandry of miniature trees. Until next time, BW, Nik.