Weirdly the definition of bark seems to be variable depending on what book or article you read. As my main reference for this post I’m using Romero’s “Bark: Structure and Functional Ecology” accessible via a free account on JSTOR here. According to Romero, bark is all the tissues on a tree outside the vascular cambium […] Read more… >
The cambium – or more precisely the vascular cambium – is a layer of cells underneath the outer and inner bark and outside the wood of a tree. It’s officially defined as a ‘meristem’ – that is, a region of cells capable of division and growthref. You may recall the ‘shoot apical meristem’ in the […] Read more… >
Fixed Growth (determinate) (leaves formed inside the bud before opening) Free Growth (indeterminate)(leaves and buds continue forming throughout season) Rhythmic Growth (a bit of both) AshBeechHornbeamOakHickoryWalnutHorse chestnutPineSpruceGinkgo short shoots ElmLime/lindenCherryBirchPoplarWillowSweet gum/ liquidambarAlderAppleLarchJuniperWestern Red CedarCoastal RedwoodGinkgo long shootsMaple Loblolly pineShortleaf pineMonterey pineCaribbean pineCocoaRubber treeAvocadoMangoTeaLycheeCitrusOlivePinus radiata From Thomas (2018) and RNETR
You’ve probably heard of rooting hormone powder, or auxin, or gibberellins – these are all ‘Plant Growth Regulators’. Plant Growth Regulators used to be known as ‘phytohormones’ which means plant hormones. This has been quite a contentious topic among plant biologists. A hormone in an animal is a chemical messenger, a substance which acts as […] Read more… >
There are a few different terms bandied about to describe buds which pop up in unexpected positions on a tree – ‘adventitious’, ‘dormant’, ‘suppressed’ ‘preventitious’ ‘proventitious’. Epicormic growth is actually just growth which forms on old-growth units of the tree – not in the current season’s growth.ref It’s great for bonsai because it helps keep […] Read more… >
Gymnosperms relevant for bonsai include ginkgo and the Pinales order (Araucariaceae, Cephalotaxaceae, Cupressaceae, Pinaceae, Phyllocladaceae, Podocarpaceae, Sciadopityaceae & Taxaceae – this is explained in The kingdom Plantae and where trees fit in). Ginkgo is a special case described separately at the end of this post. So what we’re interested in in bonsai is where lateral […] Read more… >
When a tree is damaged or injured in some way, various responses happen, but none of these would be characterised as ‘repair’ in the same way one sees the human body repair itself. Trees create new growth to compensate for damage, and seal off damaged areas to prevent infection or further damage occurring. I like […] Read more… >
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 for primary growth, and are created by meristem tissue (a meristem is an area of stem cells which differentiates into different types of cells). If you look inside […] Read more… >