Where do I start!
This chapter gives an OUTLINE ONLY description of the methods and techniques used to train or simply manage growth on trees and shrubs.
These methods rely highly on demonstration for understanding so this presupposes that you attand a practical course in training. Although certain techniques may predominate in one or other form of training, it is quite usual that a number of different techniques are used simultaneously or at different phases of the plants lifespan.
It is advisable to read the chapter on the physiology of woody plants first to have an understanding of the reasons why these techniques are used.
Although pruning (branch removal)
is popularly accepted to be the most common way to reduce and shape trees and shrubs
it is certainly not the least time consuming: and there is always the debris to be removed.
It is also a fundamental way of passing on diseases (on dirty tools).
All plants have a species form (the very way in which we recognise
them) and the removal of a limb only stimulates regrowth in a plant to
replace it. Naturally plants have evolved to 'hedge' (not just a weak pun) their
bets and to ensure success of branch replacement they make several new branches.
The harder they are pruned the more they are stimulated to regrow.
For more on pruning see the chapter on Physiology of trees
Woody plants have an 'ideal', but not exact, mirror of above and below ground branch system. Although the above ground branchwork forms a 'head' shape, the below ground branchwork forms a 'plate'. The true roots extend often to nearly double the distance from the trunk as the 'head'. Removal of below ground branches causes above ground branches to cease extending. Regular pruning or reduction of the below ground parts prevents the regrowth of above ground without 'ugly' stump lopping patterns. Root pruning can also accelerate precosity, reduce periodicity and maintain a high reproduction to vegetative ratio in the buds.
All pruning should be kept to an absolute minimum (for reasons stated above). However as with pruning Prunus it should be done after Juneus. The same reasons which apply with plums and cherries (spread of bacteria in the water film over cuts and into cortical tissue) should apply wisely to all trees. So any substantial branch or shoot removal should be done from mid July to the first part of September.(Of course this is all weather dependant.) Sap is at its minimum, and the ground and air is at its driest, so the mobility of resources for extension is low. Then there is less likelyhood of regrowth.
It seems absurd to wait till a branch has extended over a growing season when you know that you will not want it and then prune it out in the winter.
'Rubbing out' or bud pruning is done at the stage of emerging or 'breaking' bud whereas pinching or trimming back is done when a side shoot on a lateral is at the 2 or 4 leaf stage. Cutting back side shoots in late summer from pruned side shoots will ensure they do not extend and in fact increases the potential for reproductive bud formation and fruit swelling. When bud pruning is done the sap surge is at the fullest, vigour will flush any dirt (bacterial /fungal spores) from the small wound. When bud pruning is done then all the plants resources minerals (sugars principally) are directed into the shoots which you wish to retain (or fruit).
When maintaining trees and shurubs in a 2 dimensional plane (along a fence or a wall) it means you must make a tight control of shoots which may extend back or to the fore. This is accomplished by the removal of these shoots.Since their removal at some stage is certain we can rub out even as they break and if this is done every July there is no case in which they will need to be pruned. Orientation E/W helps with this- since the North side is the colder side there is an effect on the bud formation due to cold and on the South side similarly due to heat/light . So a Natural suppression takes place which distorts the inherent phylotaxis.
Unless we begin with a suitable root system which helps in the control of above ground vigour we will always be struggling against the tide of a vigorous branch growth. There are a range of rootstocks for all fruit trees (and even ornamentals) which help to reduce or enhance vigour or effect tree shape.
A 80 year old graft of a weeping beech onto natural rootstock
For more on Rootstocks please see the Appendix
It has been known for thousands of years that keeping a woody plant in a container will limit its growth. Fig trees are a good example of this and were usually planted in a stone trough (the dimensions of a Gladstone Bag, apocryphally). Citrus and Olives respond very well to container growing as well.
However container soil can become leached of nutrients and the soil humus content become burnt off (no amount of top dressing or watering with liquid feed compensates). They will also accumulate soil pests (such as root aphids and eelworms). The additional problem is that the roots will set up a circumferential ring growth pattern. Therefore it is essential that every few years the plants are removed from the container and the roots pruned radically. Cut everything back by 50% . Yes, I mean 50%! 'Teasing out' is of no use whatsoever. Do this in the dormant season and wash all soil off the root branch system. Do this thoroughly. Repot in SOIL not compost (a good loam with some clay content) into the same size pot or only 1 size larger if you wish to let it increase in size. I am with Rivers when he advises a 18inch pot - height and diameter - as optimum for keeping trees. Larger than this there are handling issues too.
Although I have written about growing in containers elsewhere -
a halfway condition, so to speak, between gound and pot is the use of planting bags.
The trees are planted in these in the same soil as the surrounding ground (not improved). It is best to ensure that the bag is completely covered with soil as sunlight will degrade the bag and it may tear on lifting.
The underground branchwork is contained in the bag but the finer, unthickened, more thread like roots can exit through the close mesh into the surrounding soil. The tree can therefore more easily be lifted (often has bag handles) and stripped of soil. The root network is automatically pruned when the bag is torn off. However with careful removal the bag can be reused. The bag can be refilled and replanted in the same hole virtually, if required. This is much more useful where watering containers would be a problem, or as a holding condition where lots of trees are in a nursery bed.
There are two principal types of bag material - close textured, non-woven polypropylene or woven nylon filament bags. The latter are much longer lasting
For more on containers see the appendix
Another useful technique to be able to grow more varieties or control size and spread where orchard space is limited is to multiple plant in the same hole.
For example 3 trees in a hole. Always work with uneven numbers. It is easier to position symetrically and space evenly. The technique has been know for A LONG TIME. You need to select trees on the same rootstock and of the same type. Either apples, or pears, or plums and related types. The types will therefore have the same pruning and treatments. The best spacings when plants are on semi-dwarfing stocks is 18 inches apart, on dwarfing 15 inches. After planting (see other notes) prune all trees (maidens or feathered maidens) back to about 18 inches (knee high), so that all the trees start with the same equal chance of development to fill the space. It is quite right to allow all the trees subsequently to develop and fill 3 dimensionally and so interlattice.
Unstylish yet effective initial restoration of a Mirabelle
It is necessary that you should read the contents of the chapter on the physiology of woody plants pertinent to this process
Since reproductive woody tissue is made precocious by age but also the position of its
parent wood relative to the horizon, buds can be induced to become
reproductive by bending parent wood down horizontally. In cultivars which are
recalcitrant in producing flowering/fruit buds then this is especially helpful.
This technique is refered to as 'espalier' and can either be 'strong' - hard bending: or 'light' - bending in a low arch.
Strong bending of vines to almost form a circle helps to keep them in check in a small garden
Also called 'brutting'. When branches are snapped and pushed downwards but not broken or pruned off they will callus and heal. However they will not extend. This is the best way to treat any water shoots as they are the safety valves of the tree. Removing them simply stimulates the plant to produce more (having leaves it NEEDS them). They allow excess water to evapourate but still contribute to the overall sugar production in the plant. It is usually done in early summer but anytime before October if there are a lot of trees to get through.
Ringing also known as Bark Ringing though strictly it is 'Rind Ringing'is a more technical procedure. It entails the removal of horizontal strips of rind from around the circumference of the trunk or branches to reduce vigour. The position and width of the strips is only learned from practice and experience . Also the nature of the rootstock /scion interaction has to be known before determining how they will be expected to react. There are other books which describe this in detail - and for the present I will not include it. It is best practised under the eye of an experienced 'ringer'.
Notching (also called 'Nicking') is a simpler form of ringing in that a small notch is cut just above or below a bud
which either stimulates it to become more vegatative or reproductive.
Generally speaking - notching below a bud helps turn it reproductive - and above, vegetative.
However this rule is too simple and it is usual to combine several notches on branches to help with the purpose.
Notching on the underside of larger branches helps with being able to bend them (particularly helpfull where they have gone a bit woody by neglect). Notching on the upper side sometimes leads to splitting or tearing and leaves an exposed wound, so don't.