Growing Japanese maples is the title of a new video series designed to teach all the ins and out of how to care for a Japanese maple. The clip below is taken from volume 1 that covers container cultivation.
In this preview, winter potting of Acer palmatum Akane is looked at but the techniques apply equally well to any Japanese maple and many others are featured in the full video, details of which can be found at Japanese maple videos.
Tuesday, August 3, 2010
Monday, August 2, 2010
Japanese Maple Videos
A brand new video series on growing Japanese maples is out now on DVD. The first volume, on container cultivation, is now available and a full description and preview clips can be found at Japanese maple videos
Wednesday, July 1, 2009
New, improved Japanese maple blog
A new, improved Japanese maple blog has now been set up and can be found at the Japanese maple guide.
Monday, January 21, 2008
Pruning a japanese maple - don't be scared!
Pruning a Japanese maple requires no special skills and is quite straightforward providing a few basic rules are followed. For older trees much of the pruning will have been done already by the tree itself. Smaller branches in the centre of the tree and branches low down on the trunk that are shaded by others will die back naturally and older trees will form the proper shape of their own accord. Pruning a Japanese maple tree is then essentially one of maintaining the shape and dealing with any straggly or lop-sided growth.
So, how to prune a Japanese maple? Firstly, try to visualise the shape you are hoping to achieve and cut to that imaginary line. If there are one or two strong growing branches that need to be pruned, cut back inside the line by a few buds as there will be more subsequent growth from these branches than other, smaller branches. A second cut can be done in the summer when light trimming of the subsequent growth will bring the tree back within your imaginary line.
When to prune is quite critical and many commentators will say you should prune Japanese maples in the spring. This, unfortunately, is bad advice as two things will happen if done at this time. Firstly, the cut surfaces will bleed. This attracts insects and is a possible route of entry for fungal infections. Painting the cut doesn't help as this just traps fungi and bacterial spores that have landed on the surface the moment it was cut. Secondly, the sap that is coming out would have been used to produce new growth and the amount of growth produced will be reduced, depending on how hard you have pruned.
The optimum time to do any major pruning is going to be between November and January but ideally it should be done before Christmas. If you have very cold winters and new growth doesn't appear until April, then January and early February is a safe time. In areas with a mild winter, root activity never fully stops and as a result sap bleeding can be quite profuse depending on how vigorous the plant is. A light trim can be done once the tree is in growth by pinching out the tips after the first two or three pairs of leaves have developed.
Slightly more substantial trimming of your Japanese maple can be done in the summer once the new shoots have lignified, ie, ripened. The plant is now concentrating on building up food reserves in the roots so sap bleeding is not an issue but remember that the plant needs the leaves for energy production so try to keep shoot removal to the minimum. Far better to wait until winter when the branch structure can be clearly seen and you can visualise your cutting line better.
One suggestion you will sometimes come across is to prune inside the tree 'to let the air in'. A moments thought will realise the fatuity of that statement; the centre of the tree does not exist in a vacuum and air is always going to get in! As I mentioned at the beginning, if the leaves of a particular branch are not getting enough light because it's being excessively shaded, it will die back of it's own accord.
Sometimes, when branches cross and start rubbing against each other, the temptation is to cut one of them out. A better course of action, especially if the bark has been rubbed off from both branches, is to tie them together. Two things will then happen; the obvious one being that they will stop rubbing. The second thing that will happen is the branches will callus and fuse together resulting in stronger growth of the dominant branch. This will normally take one or sometimes two seasons, after which the weaker branch can be cut back to the joint (but only in winter!). Polythene tape or insulation tape can be used but remember to replace it every few months or it will cut into the bark.
Heavy Pruning of a young plant should preferably be avoided for the first few years to allow it to build up strong root system but during this time it will be amenable to basic shaping depending on what type of plant you've purchased. Upright, spreading or low growing dissectum types can be encouraged to form specific shapes at an early age by appropriate staking and trimming rather than allowing them to become too open and sparse.
If you want any more information on pruning or any other aspect of their care, visit Growing Japanese maples
If you found this article helpful please use the button below to let other gardeners know about it.
So, how to prune a Japanese maple? Firstly, try to visualise the shape you are hoping to achieve and cut to that imaginary line. If there are one or two strong growing branches that need to be pruned, cut back inside the line by a few buds as there will be more subsequent growth from these branches than other, smaller branches. A second cut can be done in the summer when light trimming of the subsequent growth will bring the tree back within your imaginary line.
When to prune is quite critical and many commentators will say you should prune Japanese maples in the spring. This, unfortunately, is bad advice as two things will happen if done at this time. Firstly, the cut surfaces will bleed. This attracts insects and is a possible route of entry for fungal infections. Painting the cut doesn't help as this just traps fungi and bacterial spores that have landed on the surface the moment it was cut. Secondly, the sap that is coming out would have been used to produce new growth and the amount of growth produced will be reduced, depending on how hard you have pruned.
The optimum time to do any major pruning is going to be between November and January but ideally it should be done before Christmas. If you have very cold winters and new growth doesn't appear until April, then January and early February is a safe time. In areas with a mild winter, root activity never fully stops and as a result sap bleeding can be quite profuse depending on how vigorous the plant is. A light trim can be done once the tree is in growth by pinching out the tips after the first two or three pairs of leaves have developed.
Slightly more substantial trimming of your Japanese maple can be done in the summer once the new shoots have lignified, ie, ripened. The plant is now concentrating on building up food reserves in the roots so sap bleeding is not an issue but remember that the plant needs the leaves for energy production so try to keep shoot removal to the minimum. Far better to wait until winter when the branch structure can be clearly seen and you can visualise your cutting line better.
One suggestion you will sometimes come across is to prune inside the tree 'to let the air in'. A moments thought will realise the fatuity of that statement; the centre of the tree does not exist in a vacuum and air is always going to get in! As I mentioned at the beginning, if the leaves of a particular branch are not getting enough light because it's being excessively shaded, it will die back of it's own accord.
Sometimes, when branches cross and start rubbing against each other, the temptation is to cut one of them out. A better course of action, especially if the bark has been rubbed off from both branches, is to tie them together. Two things will then happen; the obvious one being that they will stop rubbing. The second thing that will happen is the branches will callus and fuse together resulting in stronger growth of the dominant branch. This will normally take one or sometimes two seasons, after which the weaker branch can be cut back to the joint (but only in winter!). Polythene tape or insulation tape can be used but remember to replace it every few months or it will cut into the bark.
Heavy Pruning of a young plant should preferably be avoided for the first few years to allow it to build up strong root system but during this time it will be amenable to basic shaping depending on what type of plant you've purchased. Upright, spreading or low growing dissectum types can be encouraged to form specific shapes at an early age by appropriate staking and trimming rather than allowing them to become too open and sparse.
If you want any more information on pruning or any other aspect of their care, visit Growing Japanese maples
If you found this article helpful please use the button below to let other gardeners know about it.
Wednesday, November 7, 2007
Mycorrhiza in the garden
I was probably overly harsh on the subject of Japanese maples and mycorrhiza on Friday. In practice, some benefit can be obtained from mycorrhizal treatment but overall, the difference in growth is going to be marginal, assuming that you have a healthy plant to start with. What mycorrhiza can't do is revive or improve the health of a poorly performing maple. As far as the soil microflora is concerned, boosting bacteria numbers and variety will have a far more impressive effect on the overall well-being of your Japanese maple and this is a subject I'll go into in more detail in a future post.
The reason mycorrhiza have little effect on maples is due to how they originally evolved and the types of plant they developed a symbiotic relationship with. Although it's not immediately apparent, the fine feeding roots of a Japanese maple are covered with a mass of root hairs. If you grow a seed and the initial root hits a small air pocket in the growing medium, the root hairs are easily visible. Under normal growing conditions, if you pull up a maple you won't see anything as the root hairs will be within the soil or are easily pulled off. You can see a more obvious picture of root hairs on something such as a lily bulb, particularly the roots that grow above the bulb from the base of the stem.
Root hairs serve the same purpose as mycorrhiza and specifically arbuscular mycorrhizae, as these are the symbiotic fungi most closely associated with garden plants. The root hairs penetrate the soil and provide the plant with it's nutrients in the same way as mycorrhiza do and no symbiotic relationship is required for the plant to perform 100%.
The root hairs also serve another purpose and that is as a barrier to fungi, good or bad and inoculating the soil will mean the fungal hyphae can't reach the roots and develop within them. This barrier to mycorrhiza is only present in plant species that are relatively 'new' and have developed more sophisticated forms of nutrient uptake. Acer palmatum is a very 'young' species in terms of evolution and is still unstable. This manifests itself in it's inability to produce offspring that look identical to the parent; sow a thousand seeds and you will have the majority of them unique in leaf shape and form. They may all look very similar, either red or green, but there will be subtle differences in shade of colour, the serration on the lobes or leaf size.
Where mycorrhiza can make an appreciable difference, however, is with the more 'primitive plants and I shall, hopefully, cover that tomorrow, as this type of plant is the reason for the existence of mycorrhizae.
The reason mycorrhiza have little effect on maples is due to how they originally evolved and the types of plant they developed a symbiotic relationship with. Although it's not immediately apparent, the fine feeding roots of a Japanese maple are covered with a mass of root hairs. If you grow a seed and the initial root hits a small air pocket in the growing medium, the root hairs are easily visible. Under normal growing conditions, if you pull up a maple you won't see anything as the root hairs will be within the soil or are easily pulled off. You can see a more obvious picture of root hairs on something such as a lily bulb, particularly the roots that grow above the bulb from the base of the stem.
Root hairs serve the same purpose as mycorrhiza and specifically arbuscular mycorrhizae, as these are the symbiotic fungi most closely associated with garden plants. The root hairs penetrate the soil and provide the plant with it's nutrients in the same way as mycorrhiza do and no symbiotic relationship is required for the plant to perform 100%.
The root hairs also serve another purpose and that is as a barrier to fungi, good or bad and inoculating the soil will mean the fungal hyphae can't reach the roots and develop within them. This barrier to mycorrhiza is only present in plant species that are relatively 'new' and have developed more sophisticated forms of nutrient uptake. Acer palmatum is a very 'young' species in terms of evolution and is still unstable. This manifests itself in it's inability to produce offspring that look identical to the parent; sow a thousand seeds and you will have the majority of them unique in leaf shape and form. They may all look very similar, either red or green, but there will be subtle differences in shade of colour, the serration on the lobes or leaf size.
Where mycorrhiza can make an appreciable difference, however, is with the more 'primitive plants and I shall, hopefully, cover that tomorrow, as this type of plant is the reason for the existence of mycorrhizae.
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