Bonsai-Science

May is pine pollen time at Kew Gardens and today I spent a fun hour or so taking pictures of different pine species and their pollen cones: Pinus contorta / Lodgepole pine Pinus echinata / Short-leaf pine Pinus bungeana / Lacebark pine Pinus attenuata / Knobcone pine Pinus pinaster / Maritime pine Pinus ponderosa Pinus ayacahuite...

Pine pollen May is pine pollen time at Kew Gardens and today I spent a fun hour or so taking pictures of different pine species and their pollen cones: Pinus contorta /

Of all the propagation techniques available for bonsai, air layering is surely one of the best. There are so many advantages to this practice! The main one is that it can be used on mature trees with large branches, so that your bonsai ends up with a large trunk from the beginning. If you air layer at an angle to the trunk, and/or at a junction with two or more branches, you can make it even wider again....

Air layering - an excellent technique for creating new bonsai Of all the propagation techniques available for bonsai, air layering is surely one of the best. There are so many advantages to this practice! The main one is t

A reminder that your conifer leaves turning bronze at this time of year (in the Northern hemisphere) is a natural phenomenon and nothing to worry about, as long as the conifer in question is a member of the Cupressaceae family. Leaf bronzing is a control mechanism which helps the tree dissipate excess energy created by photosynthesis in cold temperatures. By synthesising the pigment rhodoxanthin instead of chlorophyll, species including Cryptomeria japonica, Thuja and Juniperus are able to safely reduce photosynthesis and prevent oxidative damage. More about this in my post:

Why do some conifer leaves go bronze in winter? You may have noticed that certain conifer species' leaves go a different colour over the winter without dying. This phenomenon is most associated with Buxus (bo

What is a bract? A bract is a part of a plant with which many people are quite unfamiliar. Did you know that all of the below images show bracts? The petal-like structures in the first six images are actually bracts, and in the last three which show conifer cones, the spiky/protruding parts are bracts....

What are bracts and do they matter for bonsai? What is a bract? A bract is a part of a plant with which many people are quite unfamiliar. Did you know that all of the below images show bracts? The petal-like

When working with conifers it can get extremely sticky as these trees exude resins from cut stems as well as other organs such as seed cones and needles. We can use our understanding of the chemistry of these resins to work out the best way to dissolve them so we can clean our hands and tools (read on). Conifer resin helps a tree resist microbial attack, particularly when it is cut, and also acts as a deterrent to herbivory....

How to get that conifer resin off your hands and tools When working with conifers it can get extremely sticky as these trees exude resins from cut stems as well as other organs such as seed cones and needles. We can

It's probably obvious that many plants, like humans, go through different developmental phases throughout their lifetimes. In plant biology, a developmental phase describes a period of time during which a stem produces a specific type or combination of organs, such as shoots & leaves (vegetative organs) or flowers & cones (reproductive organs). In fact for plants it is individual stems, not entire plants, which go through these phases and so a single plant can have stems which each are in a different phase....

How trees mature - understanding development phases It's probably obvious that many plants, like humans, go through different developmental phases throughout their lifetimes. In plant biology, a developmental pha

Another product which pops up as a recommended one in the bonsai world is this one - SB Invigorator. This product is for pest control and claims to control "Whitefly, Aphid, Spider Mite, Mealybug, Scale and Psyllid."ref As I have recently added a lot of indoor plants to my collection, these pests are becoming rather annoying, so I have been looking for ways to get rid of them without using toxic chemicals....

SB Invigorator Another product which pops up as a recommended one in the bonsai world is this one - SB Invigorator. This product is for pest control and claims to control "Whi

Break out the cabbage pH indicator and learn how water hardness and pH affect plants - and your bonsai.

Water hardness, pH and bonsai I live in London, a city sitting on a giant chalk deposit which formed in the Cretaceous period and stretches all the way to France (via the Eurotunnel)ref Chal

The answer to this one is possibly yes.

Mulch - relevant for bonsai? If you're a fan of Gardening Australia as I *massively* am, you will have noticed they are always going on about mulch. Mulch (often in the form of bark or wood

What is nitrogen-fixing and is it relevant for bonsai?

Nitrogen-fixing and bonsai You've probably heard the term 'nitrogen-fixing' - it means extracting nitrogen from the air. Which doesn't seem like it should be too difficult, since nitroge

The crazy colours in Satsuki azalea flowers have a fascinating genetic story involving polyploids, mixaploids, transposons and chimeras. This one is a true geekfest!

Mysterious mixaploids - Satsuki azaleas and their mixed up flowers At a recent club meeting (shout out to Twickenham bonsai club) the subject was azaleas. During a critique session it was noted that on Satsuki azaleas, differen

Did you know that excess transpiration can be fatal to bonsai (and non-bonsai) trees? Learn more about this fundamental tree process, and what you can do to protect your trees.

Transpiration I've talked about transpiration in quite a few different posts on this site, but a recent thread on http://bonsainut.com caused me to think maybe I should have

Should you be concerned about frost? Read more about how frost can damage bonsai trees, particularly young roots, and what you can do to prevent this.

What does frost do to bonsai trees? Living in London means that even though spring has blossomed forth, there is still a chance of frost all the way through to the end of May. And many of us will

If you're a lover of botanical gardens, you can create your own miniature version with a bonsai pinetum. This articles gives suggestions for species to include.

Creating a Bonsai Pinetum A pinetum is an arboretum, or collection of trees, dedicated to conifers. There is a fabulous pinetum at RHS Wisley in the UK (my 'About Me' pic was taken there

Did you know that many trees have specific male flowers & cones which differ from the female versions? Read on to learn about these underappreciated chaps.

Male Tree Flowers Spring has sprung (finally) in the UK and now is the time that many trees flower, so they can pollinate the next generation with enough time for seeds to develo

It seems like a good time (in the northern hemisphere) to review what we know about tree buds, where new growth emerges. Here's an overview, with more to come in future posts.

Buds Buds are the "small lateral or terminal protuberance on the stem of a vascular plant that may develop into a flower, leaf, or shoot."ref Buds are responsible fo

A pathogen is a microorganism such as a virus, bacterium, oomycete (water mould) or fungus which causes disease and/or death.ref Examples you might have heard of include Dutch Elm disease (caused by the fungus Ophiostoma ulmi), Horse Chestnut bleeding canker disease (caused by the bacterium Pseudomonas syringae v. aesculi), Ash dieback (caused by the fungus Hymenoscyphus fraxineus…...

Pathogens - nasty tree microbes A pathogen is a microorganism such as a virus, bacterium, oomycete (water mould) or fungus which causes disease and/or death.ref Examples you might have heard o

My final post on this subject - the weird and wonderful world of flat conifer leaves.

Conifer flat leaves Flat leaves are found across the conifer families including Taxus, Cephalotaxus, and even in Pinus (check out Pinus krempfii) as well as many of the Araucariace

My next post on conifer leaves, this time looking at the prized (in bonsai) 'scale' leaves. But how do you encourage them to form on trees which have different juvenile foliage? Read on...

Conifer scale leaves Scale leaves are a curious form of conifer leaves which cover up the stem in interlocking patterns. I believe they are called 'scale' because they look a bit li

Continuing my series on conifer leaves, here is a closer look at needle leaves, which can survive down to -93°C and last for up to 45 years. Needles are tough!

Conifer needle leaves I'll be honest, I find conifer needles to be quite weird. As someone raised in the southern hemisphere, true pine trees were something we had at Christmas and t

Conifer Leaves I've been planning a post on this subject for a while because conifers have always been a bit scary to me from a bonsai point of view - they don't seem as forgi

Updated: long & short shoots, shoot development & internodes. How knowing about shoots can help you develop your bonsai tree shape.

Shoots This is a rewrite of my original post on shoots, now I know a *lot* more... So what are shoots? They are the vegetative growth which comes from buds, extendi

Some conifers protect themselves from winter sun by changing their plastids from chloroplasts to chromoplasts...

Why do some conifer leaves go bronze in winter? Some conifers protect themselves from winter sun by changing their plastids from chloroplasts to chromoplasts

A fellow bonsai enthusiast at my bonsai club asked for advice from club members on their choice of tool materials, which prompted me to look into the physical differences between the materials on offer. The bonsai tools most people have include a range of branch, root and k**b cutters, pruning shears/secateurs, scissors and pruning saws. A quick surf of bonsai stores online show that these tend to be made from steel of one form or another....

Bonsai tool materials - carbon or stainless steel? - Bonsai Science How to understand what you're buying when you buy steel bonsai tools

While many of us might simply use the hosepipe to water our bonsai, there are actually a range of options for recycling or collecting water for this purpose. I've looked into some of these below to understand how suitable water from different sources is for watering your trees. Dehumidifier water - good unless you have a dessicant humidifier and toxic air…...

Water Sources for Bonsai - Bonsai Science While many of us might simply use the hosepipe to water our bonsai, there are actually a range of options for recycling or collecting water for this purpose. I’ve looked into some of these below to understand how suitable water from different sources is for watering your trees. Dehumidifier water ...

We recently had guest speaker Amelia Williams talk to members of Twickenham bonsai club about tropical bonsai. She has moved entirely to keeping tropicals & sub-tropicals, to the extent that her back garden is full of her ex-non-tropical bonsai trees which are now planted as a foliage bed! This post references some of Amelia's talk, if you would like to read more she has written several articles for…...

Tropical Bonsai - Bonsai Science We recently had guest speaker Amelia Williams talk to members of Twickenham bonsai club about tropical bonsai. She has moved entirely to keeping tropicals & sub-tropicals, to the extent that her back garden is full of her ex-non-tropical bonsai trees which are now planted as a foliage bed! This post...

Sometimes in a bonsai context it's said that specific branches are connected to specific roots - often in discussions about pruning and carving. For example it may be suggested that pruning a specific branch will kill an associated root, or vice versa. As I've learned over the last 6 months researching this site, when it comes to trees - 'it depends'....

Root-Shoot Connections (aka 'sectional growth') - when will pruning one kill the other? - Bonsai Science Sometimes in a bonsai context it’s said that specific branches are connected to specific roots – often in discussions about pruning and carving. For example it may be suggested that pruning a specific branch will kill an associated root, or vice versa. As I’ve learned over the last 6 months re...

Updated: Plant Growth Regulators (or Phytohormones)

Plant Growth Regulators (or Phytohormones) - Bonsai Science Learn about plant growth regulators such as auxin, cytokinin and gibberellins (and why some people don't call them phytohormones)

Most bonsai enthusiasts will have come across the term 'live veins' in the context of bonsai. Live veins are strips of bark and the living tissue underneath it on or around a tree. They are often seen on juniper bonsai, where a section of bark twists around the tree in a dramatic contrast to the white deadwood (Sierra juniper are particularly amazing)....

Live Veins on Bonsai - do they exist? - Bonsai Science Learn about live veins on bonsai and which trees have sectored root-leaf routes

Getting ready to repot? Find out how carbohydrates stored in roots are impacted by root pruning at this (or any) time of year.

Root Food Storage (or, can I root prune before bud break?) - Bonsai Science Learn about the levels of food stored in roots and when they are used by plants, to understand the effect of root pruning your bonsai at different times of year