Growing fruit is always a seductive garden idea in summer when you gaze upon the laden branches of apples, pears and plums in other people's gardens, but if you're going to be successful you need to do a little research before you buy.
For a start, you need to assess how much space you have, not because you need rolling acres to do it, but because you can buy a plant to suit every situation and you might as well get the right one first time - it saves time and money.
To get your head round the mysteries of rootstocks, it helps to know a little about plant production.
Many plants with lovely flowers or tasty fruit actually have quite weak growth and, left to their own devices, they would make poor plants. Nurseries get round this by grafting (joining) a piece from the attractive variety onto a closely related plant that grows well, but has poor flowers or fruit. Once this graft has “taken” (the two plants have joined together), the plant will have the vigour of the roots with the benefit of the desired variety on top.
This is also done when the desired plant needs replicating because it will not grow from seed. An apple, such as ‘Bramley's Seedling', is a one-off because it grew from a pip. Every single ‘Bramley's Seedling' apple is part of that original seedling, because a small piece is grafted onto a rootstock to keep it going and provide excellent cooking apples.
The great thing about rootstocks is that they vary in size and vigour from dwarf and semi-dwarf to semi-vigorous and vigorous. Research work done at the East Malling Research Station in Kent led to a series of rootstocks which are prefixed with M and then have a number. This tells you the ultimate size of the tree and you can get anything from a tiny M27 to a very large M25 to suit your space.
If you only have a small area for fruit, then decide which you want. Many tree fruits, like apples, pears, cherries, peaches and apricots can be purchased for growing against a wall in a fan shape or as a cordon (single stem) or espalier (single central stem with horizontal side branches). Grown against a sunny wall or fence, these can be very productive without taking up much space.
You can also buy some fruit as columnar trees, designed to stay as a single upright stem in the border or a pot.
Currants, gooseberries and blueberries are usually grown as bushes, although gooseberries make great standard plants (with the growth at the top of a clear stem) leaving room for something else underneath.
Grape vines prefer a very warm, sunny spot to fruit well, but are ideal for wall-training, again leaving space for other plants down below. They can also be grown in containers.
Training and pruning
This is the aspect of fruit growing that worries most people. We've all seen neglected old apple trees with a mass of tangled, congested growth and tiny wizened fruits.
The key is to begin training the plant straight away, using a good book with clear diagrams or see if you can attend a local hands-on course on seasonal pruning.
Have a clear idea in your mind of what you want from the plant. Free-standing fruit trees can be trained into all sorts of shapes (for instance pyramid, crown or goblet) to suit your taste. Wall-trained trees can be cordon (upright single stem), oblique cordon (single stem at an angle), fan or espalier.
For the best crop on most apple varieties, you need to develop a system of fruiting ‘spurs' (clusters of fruit buds together), but pears may bear the fruit on the shoot tips, which means careful pruning at the right time or you risk removing the fruit buds for the following year.
Tips of the trade
Keep the tree small enough to allow easy picking and treatment of pest or disease attack.
Treat any problems early, before they can take hold.
Fruiting is better when the branches are horizontal (it distributes natural plant hormones more evenly between the fruit buds) so you can use string to ‘festoon' the young shoots (tie pliable shoots into a horizontal position) to improve the yield.
For more information and garden ideas:
The Pruners Bible by Steve Bradley
The Pruners Handbook by Steve Bradley
RHS Pruning & Training
The New Fruit Expert by Dr D Hessayon (recently revised and updated by Steve & Val Bradley)