This gets a bit long, if you are in a hurry you can skip the preamble….

Preamble – BS for starters

Before I get into todays main course please allow me to apologise for the lack of blog posts so far this year. I don’t have a precise explanation for my absence. In modern parlance I feel I have been suffering from what’s known as an acute mental health crisis. That might sound serious because that’s how modern society likes to use language. Back in the days of plain English we would say I’ve been a bit naffed off, fed up or depressed.

Yesterday I fell off a ladder and am a bit banged up so here I am making the most of my straitened mobility.

Now I know a great deal of you lovely people look forward to my ranting, raving and spouting bollocks and I am truly sorry to have deprived ya’ll of a smile but honestly I have been moments away from throwing in the towel this year. I have been ready to close our doors and get a job delivering groceries.

In the words of the immortal Larry Love – Alabama 3 – Terra Firma Cowboy Blues
The world don’t seem to fit me
I’m always starin’ at the stars
A better life for me in some other galaxy
I wanna get off this world of oursI got a telescope on the roof
I’m always searchin’ the stratosphere
’cause breathin’, breathin’ it ain’t easy
In this loveless atmosphere

WTF happened to my country? Great Britain was once the envy of the world or some parts at least. We invented most things and perfected the things we didn’t invent. We largely, by some measure, invented modern civilisation and stood up for its values (with a few inevitable blind spots). We even gave the world our language and now we seem to have literally flushed the lot. We’re in such a f**ing mess our idiot leaders can’t even decide how many genders the human species contains.

Sadly I’m not the sort of bloke to just laugh this all off and when government regulation and rules have cut my livelihood in half I take the situation as seriously as a heart attack. Britons are literally drowning in liquified bullshit and most folk appear to be asking for seconds. Just don’t ask for a straw or plastic spoon, they’ve been banned. If you go to a regular job and spend your time looking at sport I guess life is pretty good. Thumbs up if that’s you, salute!

Personally I have no time for sport. I have never watched a football match in my entire life and the only ‘sport’ i got into for a short while was F1 (IMHO now a load of tosh) but trying to get sports removed from my Sky package this year was almost impossible. I told the guy on the phone I want it removed entirely and after fifteen minutes of refusing my request he’s like “Why wouldn’t you want to watch sports?” In the end I had to say “look you cloth eared c***, you either remove sports or I will cancel my package entirely, then I’ll come over there and shove this box up you hole personally.” Obviously that went down well with a retort along the lines of ‘no need to take that tone’. After an hour and a half I got what I wanted but now they call me up every few days and ask if I would like to get it back. Take my advice, give Sky a wide berth if you can.

Here’s how I lost another 2 hours of my life last week. These days I drive old school Toyotas, the type with a heavy steel chassis and over-engineered diesel engines that do a million miles between oil changes, they don’t break down, but for my good lady’s peace of mind we have, for over fifteen years, paid the AA for breakdown and recovery services. In all those years I have called them out twice, once when my old beater of a Mercedes van wouldn’t start out in the middle of the woods and another time when Catherine’s Mini (BMW) went to shit. I now no longer have German vehicles.

It’s a little known fact that Stonehenge was actually built using a Toyota Hi-Lux. Forget all that Tony Robinson crap about wooden rollers, boats and dragging stones across from Wales, that’s a crock, the Japanese were well ahead of the game as always. The only reason the boffins don’t know this is that they never found it, it’s still running about the middle east with a 50 cal’ bolted in the back. Had the builders used a Mercedes the rotting husk would have been found in the bottom of a deep pit round the back along with the detritus of packed lunches, broken Thermos flasks, busted shovels and well thumbed tatty copies of Mayfair and the Daily Sport.

One of the most influential factors in human development. The Toyota Hilux!

So, I get my renewal through and it’s about £275 because I am their longest standing customer and they really value my loyalty. Now I remember when this cost a fraction of that sum and when I inquisitively look online new members are getting the same cover as me but for just £108. You know what comes next right? I get on the blower and after what seems like a very long time a chipper young fellow answers my call.

I raise my issues but he tells me i’m wrong and my renewal figure is what it costs to actually run the service…..that I don’t ever need to use. So after some back and forth he’s not so chipper any more, I can have that effect on people. I get him to back down and he offers me £50 off which I politely decline. Now I’ve got him on the run I muster the big guns, this is fun and my renewal price ends up at the £108 I can get online as a newbie. He’s so chuffed he got me over the line but my opinion is that if he can offer the service for that figure that’s what it should be all along right? I really don’t appreciate their pissing up my back and telling me it’s raining. I kept them on the phone for 2 hours and never renewed.

The AA are a conning bunch of robbing bastards even if their breakdown service is pretty good in my limited experience. And, just to put a cherry on the cake today I got a letter offering me the service for £39. When I looked into that it actually cost £59 but you get a voucher worth £20 for a posh shop I never use because i’m working class. I remember when the AA was a respected organisation and a British institution to be proud of. I recon they’re a bunch of chiseling grifters these days. If you happen to work for this once august institution i’m sorry.

My glass has never been half full, but this sort of experience is now the norm in our country. Everything is geared towards big business and us little guys just don’t stand a chance. I’m not even going to get into our so called ‘government’ who are hell bent on controlling everything and taking care of nothing. They shit on my head whilst telling me it’s a fashionable new hat the’ve provided for me entirely free which is cool right? But what CAN the little guy who didn’t go to the right school or descend from the right bloodlines do? Well I can spout on about bonsai trees for a bit….

How To Stop Killing Bonsai Trees – Thoughts On Winter Care

So, it would appear I have gotten off track somewhat. My original intention was to put together my thoughts on how folk have been losing lots of bonsai trees this year so here goes……..

I have seen and heard a considerable number of what we might politely call ‘bullshit theories’ alongside some insightful but occasionally ill-thought out conflations about what’s been going on. It’s not just us bonsai folk, right across horticultural disciplines heavy losses have been seen. My only concern is that we learn what we can and not in a “Join the AA for just £39 or £275 for the exact same service” type of way.
So for what it’s worth here’s my two penn’orth……

Anyone remember to winter of 2010/11? It’s actually got a dedicated Wikipedia page. That was a cold one here on the normally mild east coast as relentless onshore winds cut us all down to size but across the whole country it was flippin’ taters. Bonsai tree losses that year were off the scale catastrophic. Previously we had more than ten years of largely mild winters and most of us were lulled into a sense of false security and marginally hardy trees like tridents, Chinese elm, Japanese black pines and Mediterraneans were left outside where, as it happened, they froze to death. I know folk that lost tens of thousands of pounds worth of the most amazing bonsai trees.

During the autumn of 2010 a bargain fell into my lap in the form of a massive ancient cork bark Chinese elm. I picked it up locally for a song and it filled the back of my van. This was a spectacular tree and the best of it’s kind I personally have ever seen. With my then limited experience of the variety I just left it outside for the duration. The tree never came back into leaf and ended up in my log pile and it broke my heart. However I know for a fact it had spent many years outside further inland where it’s always colder in winter than it is here on the coast so what gives?

Come summer of 2011 it was literally impossible to sell trees of any type, the whole community seemed to be reeling from heavy losses and were too shaken to start filling up their benches once again. Confidence was severely undermined and it took all of us a long time to get over what we had experienced. However we largely have short memories and by the following year everything was back to normal though lots of folk set up overwintering facilities which were largely not needed as winter temperatures returned to normal.

This last year was an odd one and that makes it hard to read or understand why problems have been so widespread. Certainly where we live the temperatures didn’t get that low. We got -5° C where we would normally see -1°C at worst but then that’s hardly a low temperature where hardy plants are concerned. We had some wet patches too but nothing particularly unusual. Last summer was nice, warm and sunny. Forget the media hype it was a beautiful warm and sunny summer but, for heat, not a patch on what our friends in Spain or Italy experience every year and they do just fine. Most folk across the country lost something so it’s not down to the individual so what? What went wrong?

The activity of plants are dictated by light. Wiki’ states…..
Photoperiodism is the physiological reaction of organisms to the length of night or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods. They are classified under three groups according to the photoperiods: short-day plants, long-day plants, and day-neutral plants.

What this means is that our little trees sense the daylight hours increasing in spring and begin to move into a growth phase. The rate or speed of that growth is dictated by temperature but it’s not triggered by temperature. That’s why a hawthorn may be showing red buds by mid-January when folk begin to panic and demand I send their soil by emergency courier because they MUST re-pot today. However the temperatures in January are normally what’s locally known as ‘basterd cold’ and so whilst your beloved thorn may well be showing signs of life it’s literally months away from developing proper leaves until day length and temperature increase a good bit.

Now this photoperiod is not just responsible for triggering spring growth but everything a plant does. Leaf formation, shoot extension, flowering, fruit set, secondary hardening of growth, root formation, wood production, the next seasons buds and WINTER HARDINESS are all dictated by day length. When the days are long most plants are growing for all they are worth because certainly in Blighty the summer is pathetically short and light intensity is never ideally high. As the light fades later in the year, shoots are done growing, roots are formed and the following seasons buds are in place a tree will begin to mature new growth and prepare for winter. The general consensus is that they need night time temperatures down to +5° C for a few weeks for this to kick in. What happens inside the tree varies by species and it’s too complicated for us to fuss over.

Last years nice warm summer was an absolute belter and our trees, assuming we took advantage, should have had an amazing year which based on my own experience they certainly did. Plants ONLY get their energy from the sun and a nice bright one means our trees have high energy levels and should be able to get a lot done and be tough and resistant to just about anything. However last year temperatures were high late into the autumn and then cold came in early. On the coast here temperatures never drop below freezing before mid-January onwards. Last year that happened in early November whilst a great deal of my deciduous trees were still in full leaf.

As the day length begins to shorten significantly a plant has a lot to do in a short period though to us it might not appear to be all that. Just because a tree is not growing or has no leaves don’t think for a moment nothing is going on because it IS. So, what’s happening?

A tree in full leaf stores a great deal of its energy, in the form of sugars, in the foliage. The development of fall colour happens because a tree is preparing for winter and will draw out as much valuable resource from every leaf as it can starting with the green chlorophyl. Once the process is complete most deciduous trees instigate a process known as ABSCISSION from Latin ab- ‘away‘, and scindere ‘to cut’. This causes the leaf, or fruit, to drop.
A plant will abscise a part that is no longer necessary, such as a leaf during autumn, or a flower following fertilisation. Most deciduous plants drop their leaves by abscission before winter, whereas evergreen plants continuously abscise their leaves. Another form of abscission is fruit drop, a plant abscises fruit while still immature in order to conserve resources needed to bring the remaining fruit to maturity.

Abscission occurs in a series of three events:

1) Resorption –
Resorption involves degrading chlorophyll to extract the majority of its nutrients. Nitrogen is found in chlorophyll and is often a limiting nutrient for plants, which need large quantities to form amino acids, nucleic acids, proteins, and certain plant hormones. Once nitrogen and other nutrients have been extracted from chlorophyll, the nutrients will travel to other tissues of the plant. Resorption is what causes leaves in the fall to change colour. Carotenoids in the leaves are slower to degrade than chlorophyll, so autumn leaves appear yellow and orange.

2) Protective layer formation –
Cells under the abscission zone divide and form a layer of cork like cells. Situated on both sides of the abscission zone are layers of parenchyma cells, which produce and inject suberin and lignin under the abscission zone into the new layer of cork cells. Suberin and lignin create a durable and waterproof layer for the plant once the element is detached.

3) Detachment –
This step can occur in a variety of ways depending on the species but always occurs at the abscission zone. Detachment can occur when layers of parenchyma cells secrete cell wall enzymes to self-digest the middle lamella or membrane, which holds the cell walls together at the abscission zone. This causes the cells of the abscission zone to break apart and the leaf or other plant part to fall off. Another way detachment occurs is through imbibition of water. The plant cells at the abscission zone will take in a large amount of water, swell, and eventually burst, making the organ fall off. Once detached, the protective layer of cork will be exposed and the area is protected and sealed off from the outside world.

Another thing a tree must get done before winter is the hardening off of new growth and roots. This is achieved by the formation of lignin. Lignin (woody tissue) is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. Simply put, soft vegetative tissue become fibrous which gives it the ability to resist the effects of freezing. This happens throughout the summer and autumn. Last year I had maples making strong extension growth throughout September and the first half of October. Most of this did not harden off fully before the frost came and as a result was lost to the cold.

By now it’s obvious there’s a lot more going on here than might appear to be the case from casual observation. A bonsai tree is a tree largely cultivated in a very un-natural situation and very often a very long way from it’s natural environment. For instance mugo pine growing in the Alps stand temperatures below -40C in winter and are often buried in meters of compacted snow. The roots are frozen solid for months on end and therefore bone dry. At sea level where, certainly in this country it’s not frozen for most of the time but it is sopping wet thanks to rain and cool conditions the roots are waterlogged for months on end and so can rot. So a tree that lives in one of the most extreme climates in Europe can die spectacularly in a soggy warm British winter which brings me neatly onto my next point.
What’s the deal with freezing? Without water there would be no plants….or any other life come to that and, much like the other ‘water of life’, in the right place it’s a great asset. However too much can be a bad thing and too much for too long is almost always a very bad thing. One can go from being lucid to ludicrous to hospitalised in a very short time much like a bonsai tree though the latter’s going to show delayed onset of symptoms.

It’s commonly stated that 50% of a tree’s weight is water. But the moisture content of different living tree species can range from 60% to 200%, where there’s twice as much weight from water as there are wood fibres. So obviously this is important.

It’s a very long time since I went to school and back when I did go I didn’t actually go very often. Even when did go to class I was far from a model student and spent my time being a right little knob. One subject I did okay in was physics, it seemed like a lot of common sense to me apart from all the equations of course. One thing they did teach me was about water, it provides a reference point for things like temperature scales etc’. That’s because it’s everywhere and very easy for folk to reference. It can be solid, liquid and gas all within a fairly narrow range ie: from freezing to boiling point.

When water freezes it expands. As a liquid the molecules huddle closely together but as the temperature falls and the water cools down, the intermolecular forces increase, the freedom of movement of water molecules decreases, and they become less and less energetic the colder they get. When water reaches its freezing point, the movement of its molecules become negligible as they take on a more defined shape, arranged in six-sided lattices. This crystalline arrangement of water molecules is less dense, as it prevents molecules from huddling up due to stronger intermolecular forces. This spacing of molecules and keeping them fixed in that position increases the volume of water, which is why it’s said that water expands when it freezes. Typically freezing water increases it’s volume by 9 > 10%.

Trees are a naturally closed hydraulic system made up of cells, think of those cells like inflated tea bags. Put a row of them together and fill one with water and before long the water will be dissipating into the adjacent ‘cells’. There is strong cohesion between water molecules because of hydrogen bonding. A continuous column of water is therefore pulled up the plants stem in the transpiration stream by evaporation from the leaves. As water travels through the xylem in the stem and leaf, it is being replaced by water taken up by the roots. When water freezes it expands putting pressure on the cell walls. If these are not sufficiently strong, as in the case of tender plants, to accommodate the expansion the cell walls rupture and the water column will be broken. Where this happens extensively the plant may not be able to repair itself or recover. The damaged area and that above it will eventually die completely.

Here’s a couple of amusing examples from my own refrigerator, a place in our house where good vegetables go to die. I recently found a bag of rather disturbingly shrivelled soggy looking carrots. Some were not rotted but could easily be bent end to end. I gave them a rinse and put ‘em in a glass of water. Two days later they were as good as new, rock hard and as firm as the day they were plucked from the ground. I ate the lot and they were good. Just like the tea bags the water soaked from cell to cell until everything was back to normal. No, i didn’t put Viagra in the water!

I currently have a lot of cucumbers in that same fridge. Some have been there for weeks and are floppy but some are nice and fresh. If I were to put one of each in the freezer overnight upon defrosting the rigid one would largely turn to liquid because it’s thin cell walls are broken and the water will escape, it’ll be a mess. However, the soggy one will be in a slightly better state and this is the salient point because, at the outset there was less pressure on the cell walls which allowed for the expansion, less damage was done and less water is lost and we can make some nasty soggy sandwiches with it.

Frozen water (ice) is dry….obviously. It’s why your freezer keeps food good for years on end because where there is no water bacteria cannot ply its trade. Our Alpine mugo pine survives months without water over the harsh frozen winter but how? In very severe cold climates native trees remove water from their cells, tolerating the dehydration of the cell contents, and place the water between the cells where it can freeze without causing damage. This works where the weather provides a prolonged slow descent into extreme cold.

Larch roots desiccate in winter and should we be poking around down there too early it the season they appear dead, just a black outer membrane and a thread down the middle. However all is well because come favourable conditions the root will reinflate itself and carry on as before. It’s a protection measure to prevent roots from freezing damage. Bear in mind larch grow very well with wet feet in damp places where simply shedding water is not possible. Most plant species and tree species in particular have what often seem fantastical winter (or summer) survival strategies to deal with extremes of climate.

From the above it’s obvious we may need to consider the effects of water in relation to overwintering our bonsai trees. In some instances we may need to take some practical measures but as always consider your actions carefully and go steady.

Temperature is another factor that can have a significant effect on trees in almost every aspect of their existence as we saw earlier. Thankfully here in GB we don’t see those extremes. I say that because I believe the British media are a bunch of tossers (by and large) we do not have extremes. We have what’s called a temperate climate ie: those without extremes of temperature and precipitation. The changes between summer and winter here are invigorating without being frustratingly extreme. There are two types of temperate climate: maritime and continental. The maritime climate is strongly influenced by the oceans, which maintain fairly steady temperatures across the seasons. Since the prevailing winds are westerly in the temperate zones, the western edge of continents in these areas experience the maritime climate. Such regions include western Europe, in particular the UK, and western North America.

I won’t be delving into the intricacies of that particular aspect as it’s not really a concern for us. However do bear in mind not all trees or their multitude of species and sub-species are the same and so knowing what you have and understanding its natural range is important. As an example take the genus Acer this contains the varieties ginnala (Amur maple) and buergerianum (Trident maple). The former can withstand temperatures down to -45C whereas the trident will be dead around -6C. So, know your plants.

We can see, thus far, that getting our precious bonsai trees through an unpredictable British winter is always going to be a bit of a weather based crap shoot. Earlier I remarked that a bonsai tree is a tree largely cultivated in a very un-natural situation and very often a very long way from it’s natural environment. Our mugo for example is a fish out of water here in soggy GB. However plants are tough and adaptable which is why we get away with what we do.

Bonsai are never going to have a large enough root system to really thrive. Anyone who has grow material in the ground will know how fast a tree can bulk up once established. Compared to pot cultivation the development rate can be 10x faster. Mother earth knows how to take care of her trees. I also wrote here years ago about how capillary action turns a shallow pot into a puddle in winter. Also bear in mind a tree with its roots in the ground enjoys a fairly stable temperature. In winter even if the surface is frozen solid, just a little below the surface it’s +4°C. A bonsai trees roots will be almost the same temperature as the ambient air. Plants in the ground don’t typically see more than a few degrees of temperature change whereas a bonsai could easily see a 20 or 30 degree swing in as little as 12 hours, particularly in summer or during a cold snap. That’s unnatural and a tree like trident maple will not cope but then our mugo pine is going to be just as vulnerable because at the altitude where they occur naturally in never gets warm, even in summer. A pot sitting in direct sun in summer can easily hit 40°C or more. Ever seen one steaming when you water in the early evening?

Having set out in brief (???) some of the more significant points concerning the survival of bonsai trees over winter please allow me the indulgence of expressing some personal opinions and observations. Because we are clever bastards we can grow trees in little pots, many are tough enough to stick two fingers up at us and carry on regardless but some are not.

Most of the bonsai trees that end up dead are not the result of weather, disease or pests. Dead bonsai are almost always killed by their owners though likely not on purpose. Nowadays we refer to that as abuse, a widely used and abused term. Abuse is when someone causes harm or distress. It can take many forms, ranging from disrespect to causing someone physical or mental pain but in this case most often it’s a case of neglect and ignorance.

In bonsai we can define the term as not providing the appropriate conditions and materials for our charge to thrive and survive. Like a customer of ours from years ago who spent a lot on a stunning tropical variety of bonsai and insisted in keeping it inside his log burner (the doors were open) all year. It looked nice apparently but as I warned him that wouldn’t last long and it didn’t. It never ceases to amaze me how newbies know so much more about bonsai than those of us who have spent our lives learning. Ya’ can’t educate pork!

In order to get a bonsai tree through the winter in tip-top condition it’s important that it’s in tip top condition long before the winter even starts. In my experience (we buy a lot of bonsai collections) the larger part of trees called bonsai in this country are no more than a harsh winter or two from the compost heap and so when adverse conditions come along, way too many are left with little defence. Kind of how many folk are just one or two pay checks away from financial oblivion.

I write here ENDLESSLY about inappropriate re-potting of bonsai trees and that’s a VERY significant reason why so many trees die over winter, they just never get to build a mature root system or reach a stable equilibrium.

Case in point, back in 2019 I recounted The Tale of Two Maples. It’s interesting to look back and that sorry little deshojo featured, it’s still with me, just compare these pictures taken four years apart at the same time of year. Which do you think will stand the best chance of surviving the winter?

Deshjo Maple Bonsai in a poor state

Deshojo maple bonsai September 2019. Not looking good.

Deshojo maple bonsai tree, How To Stop Killing Bonsai Trees - Thoughts On Winter Care

Deshojo maple bonsai tree. September 2023. Hale and hearty. This will go through a tough winter safely.

It’s a long story for another time but illustrates my point, we need to work hard, sometimes by not doing things, to ensure our trees are supremely healthy at all times. That way they are going to shrug off adverse conditions much more readily than not. Only a fool would expect a pint swilling, pie eating 40-a-day sofa spud to go run a marathon successfully. That’s got disaster written all over it. But, a poorly bonsai tree in an inappropriate pot, the wrong soil structure, badly situated in the garden that’s been badly pruned to the point of weakness and poisoned with inappropriate use of fertilisers, pesticides and fungicides does not come through a bad or unpredictable winter and everyone goes looking for some exotic disease or similarly lame reason to excuse their own long term failure. Others, and I have heard this a thousand times tend towards the “it just died, I don’t know what happened, it’s been fine for years” type of platitude.

I’m yet to see, or hear, of any tree that committed suicide. Given appropriate conditions trees don’t die wether they are in a pot or their natural environment. Where a tree in nature does die it’s because things have changed, trees have grown up around it, successive dry or wet seasons excess or lack of sunlight or nutrient poverty. There’s always a reason but much like our dead bonsai trees after a rough winter it’s not always obvious even though everything we need to know is right there. Trouble is once the piece of paper with the verdict is handed over 9 times out of 10 it’s got our name on it hence …… How To Stop Killing Bonsai Trees – Thoughts On Winter Care

If you have managed to read this far I’m betting your head’s going ding-dong about now so by way of a little light relief lets look at some practical examples based on my experience. There can’t be many of us that have not or do not have trident maples. Now I already touched upon their being particularly susceptible to freezing. This year I lost count of the folk calling me for advice on the variety so what typically happens?

Tridents, much like Chinese elm are really warm weather trees. They grow at least 6x faster in a greenhouse than they do outside in my garden. In the winter, assuming the soil is very dry they will be okay down to about -5°C but if their soil is really wet or waterlogged, which is almost always the case outside, they won’t. A combination of thick fleshy root structure, the soil we tend to use for thirsty deciduous bonsai, shallow pots and pretty moss coverings to the soil surface all mean a tree sitting outside under the sky is likely to end up very soggy. When this freezes hard the roots, other than thick lignified parts, are quickly lost due to excess internal water expansion and hydraulic pressure from outside. Just try adding an additional 10% of soil into an already full pot, hydraulic pressure caused by expansion of freezing water is easily sufficient to bust open even the largest and strongest ceramic pot. Just think what it’s doing to soft tender roots.

Now assuming this maple was going great guns all summer and shut down correctly in autumn it will have stored a lot of energy in it’s woody structures. Come spring time the tree will leaf out like normal but then growth will slow really quickly, leaves may be normal to begin but as a shoot develops the size rapidly decreases before typically the end of the shoot stops, may droop, discolour and eventually dry out altogether. Other leaves are lacklusture and will quickly discolour, curl up, or down and all activity quickly ceases. At this point most folk start thinking about ‘feed’. That’s a bullshit expression as I have said before, you can’t feed a plant but enough of semantics.

What’s happened in this example is that the tree has stored it’s previous seasons energy like a battery. At the appropriate time this has fired up and got the motor running. Trouble is over winter some little bastard came in and syphoned off the tank so there’s nothing behind the battery to really kick up the activity after the starter got us running so progress quickly stalls. The tree remembered it had a root system so chucked out an appropriate amount or new growth which quickly collapses because the frost took the roots away. Because most or all of the roots are gone the water column collapses, foliage cannot be supported and most times the tree will eventually die completely though, typically it’ll linger until well into the second half of summer, teasing you all the way.

At this juncture some bright spark’s going to ask what’s the difference between a tree that’s had it’s roots nicked by frost versus one that’s had them all chopped off in an overly enthusiastic re-pot. Trust me there’s all the difference in the world but my heads now getting too tired to explain. Health, vigour, timing and new soil all have a part to play

Sometimes a bonsai tree in this condition can be saved but it’s not an exact science. As discussed, a supremely healthy tree has significantly better odds. What has worked for me, and others I have shared this with is as follows. Keep under cover protected from rain exposed to as much sun as is possible and out of the wind. Assuming there are leaves do not mist, spray or foliar feed, we’re on battery power here. Keep the soil dry, if there is moss remove it entirely so you can see the actual soil. A small weed or two is helpful. When the weed wilts flat onto the soil you know the moisture level is about right. The most critical element of this is that soil moisture level and maintaining it right on the edge of almost too dry.

What we are doing here in effect is rooting a big cutting and if luck is on our side and damage is not too extensive it will work. The combination of a little stored energy and some small input from the leaves might just be sufficient to fire off a few small feeder roots which in time will develop sufficiently to restore the water column. Think of Bear Grylls making a fire from a spark. A tiny fleck of dry tinder smoking lightly, with care develops into an ember that’s slowly cultivated into a tiny flame and so on. Once new extension growth, which should be left to aid recovery, is romping away at one or two feet long we can begin the application of a tiny amount of fertiliser. Once you have seen good autumn colour and a text book leaf drop, breath a sigh of relief.

Bearing in mind what I said earlier about the effects of light and temperature on preparedness for winter. Where trees are grown in a greenhouse or polytunnel it’s fair to expect much faster development than is possible outside in most parts of our country. My advice is come mid-August move deciduous trees outside into full sun and an exposed position. This will ensure the tree shuts down for winter in the appropriate way and time frame. Where trees like trident are concerned I would move then back inside after a couple of light air frosts. Good air circulation and soil moisture management will ensure the tree emerges from winter as fit as a butchers dog. Where trees are put inside for the winter but not intended for greenhouse cultivation in summer move them outside by the end of winter. Don’t worry about light air frosts but if temperatures are likely to drop more than -2C you’ll have to hump ‘em back in for a while.

Evergreen trees used for bonsai that are particularly susceptible to British winters include yews (taxus), Mediterranean broadleaves like olive and Holm/Barbary oaks and Japanese black pines. Yew will do best if it’s soil is bone dry over winter. Yews hate wet feet at any time of year and whilst they may tolerate a wet winter it’s just a matter of time before Phytophora (The Plant Destroyer), a genus of water borne moulds finds just the right opportunity to kill your beloved tree stone dead in just a few weeks. Water really is the enemy of overwintering bonsai in Blighty, significantly more-so than the cold. I know folk will kick at that because their yews have been outside for decades. However just look at the losses this year country-wide. I lost yews like that decades ago but since adopting the above action, and late summer re-potting i have not lost a single leaf from a taxus over winter.

Where pines are concerned things are much the same. Most varieties of pine have relatively poor root systems and the tree relies heavily on it’s interaction with mycelium, a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. This collects water and nutrients which it passes onto the tree in exchange for sugars from the leaves. If this fungi is in poor condition pines quickly become weak with poor foliage colour and reduced growth. Mycelium seems to hate wet conditions, particularly when water freezes in its direct contact. One of the reasons coarse soil mixes are recommended for pines is that drainage is good which promotes development of mycelium as well as allowing large volumes of space between particles for the fungus to occupy. Mycelium allows trees to colonise areas that really do not have enough water or nutrient to support them without the interaction.

To keep a pine tree happy just make sure the conditions are ideal for it’s supporting mycelium and all will be well. This, once again means managing soil moisture over the winter but with the added complication of finding enough light. I’m reminded of the time a few years ago that I came by the most incredible 5 trunk kabudachi Japanese white pine. A massive mature 5 trunk bonsai tree and the best of it’s kind I have ever seen in GB. This came as a PX from a customer in the central belt of Scotland. It arrived here and instantly I could see it was not happy, it was yellow. Being September I was aware there was little time to correct this before the cold arrived. The tree was also covered in algae and lichen, it had obviously been too wet for much too long, not an uncommon problem in that part of the world.

To remedy the problem I immediately set it up in the centre of the polytunnel where the through-draft was significant. I then put a large growlight directly over it’s apex set to run 3 hours either side of dawn/dark to extend it’s day length. After the moss was stripped and I got rid of the lichen and algae I crossed my fingers and waited. By early December, with not a drop of water for over 10 weeks the tree was a pristine blue and the mycelium was growing out of the pot. I then dispensed with the light and it went through the winter perfectly and the yellow never returned, I never did re-pot it or change the soil. Old bonsai need careful and intelligent management if they are to live their best lives.

Finally please allow me to make some observations about spring. Back when I started all this malarkey decades ago spring time was end of march to early June. The Met’ office conveniently dissects the year into four quarters based on the typical weather which as we have seen is much less important to plants than is the daylight. The fact some feckless weather presenter tells you it’s spring because of the date does not make it so from the point of view of your precious bonsai. I wrote at great length about this and it’s relation to repotting bonsai previously When To Re-pot Bonsai Trees. It’s spring when a particular tree begins to grow, not just swell buds but open out and grow. This is one of the most valuable lessons I have learned in well over thirty years of fanatical bonsai work.

This last year really did test this notion for me. We like the idea of seasons and a nice defined difference between them all but, living in Blighty that’s just not possible. August 2020 saw us endure single figure temperatures below +5°C and this year whilst most folk were sweltering in a mini June heatwave here on the east coast temperatures were more like early April thanks to biting cold northeasterly onshore winds. I dare say many of you have similar tales of the place you call home.

So based on my own advice my collection of big old Chinese elms were pushing genuine leaf come mid-March and this was really happening fast probably down to a surfeit of energy from the previous, amazing summer. I got a bit caught up in the moment with uncharacteristic enthusiasm and got my re-potting done. However I should have listened to my typically negative inner voice but wishful thinking got the better of me. March is not largely ‘plant spring’ even if it is meteorological spring and I ought to know better at my age. Talk about pissing on your chips!

What happened next was that the temperatures dropped. February is normally not so bad here if the wind does not come from the north or east and this brings things on quickly. That almost never lasts and cold’s never far away. So this year by end of March it was colder than it had been at any point over the winter and it did not warm up to an appreciable degree (by which I mean steady night time temperatures of +12C or above) until the third week of June. So my elms were getting ready to go in March when I foolishly cut their root systems back by 60-80% and then almost immediately we got back down to low single figures by day and frosts at night, new roots didn’t grow and sap froze solid.

What I managed to achieve was a great success in bringing my elms through the winter only to inflict the damage of a harsh winter upon them in my silly enthusiasm and blind hope of a nice summer. Thankfully nothing was lost though none of the trees made growth worth a damn. I lost an entire seasons development which if you know Chinese elm you will know that’s quite a loss. By comparison I bought in a couple of big monster elms in the spring which were not repotted and they have grown about 2-3 feet alongside mine which have made 3” at best.

This whole subject is so full of ifs and buts it’s impossible to give precise advice on what to do for the best. It’s important to keep our whits about us, look at the bigger picture and not just rely on what may have worked for years on end. Overall the best plan is to have extremely healthy bonsai. If your tree does less now than it used too or shows any signs of distress or slowing down, like poor growth, early leaf drop, naff colour or not drawing water from the soil strongly beware. Remember water is more an enemy than cold and never, for a minute, trust the weather. Keep in place a good care regimen of appropriate watering and fertilising (with a season appropriate product) across the growing season. Keep your tree in an appropriate place based on its natural habitat and only water once soil begins to dry out. The constant drying and wetting of bonsai soil is a key element in our success, excess wet is often a very significant part of failure. Most trees roots require moisture but not water and keeping that constant is our challenge.

This subject is broad and deep and I feel I have barely completed an introduction here. Accept my apologies if I have missed anything, i’m doing my best. However after 2 days writing my head is fried and I have other things to do but hopefully this has been a help in casting a light on what happens when we get a bad winter. The takeaway is this….. Trees don’t die, most of the time they are killed by our ham-fisted oafishness and misguided well meaning ‘care‘. Sometimes it takes us a few years to kill our bonsai. Bonsai requires constant vigilance, understanding and effort and a relentless dedication to our own education. It’s not about having the latest ’snake oil’ wonder product or some special soil mixture or ingredient. Success in bonsai is about knowledge and experience and care, it’s about effort, hard work and dedication, often to the exclusion of almost everything else. If you have to stop your bonsai activity to go eat success is going to be a challenge.

Please feel free to comment or contact me by email if this has raised questions and i’ll do my best to respond. If you did manage to read all of this then I salute you. Sadly i’m fresh out of medals but you deserve one 😉 Thank for your time and support, please share!