General Pruning Tips
The following information is very general. Some plants require special pruning techniques, and will suffer if pruned improperly or at the wrong time. It is always best to check with a good pruning book, or speak with a specialist in the field of pruning if you have any concerns.
Ornamental Deciduous Trees      Most varieties prefer to be pruned in the winter, but there are some exceptions. The following varieties prefer to be pruned in mid-late summer because they will bleed less, and be less susceptible to disease: Betula (Birch), Laburnum (Golden Chain Tree), Prunus (Cherry), and Tilia (Linden). Poplars prefer to be pruned in early winter, rather then spring or summer.      Pruning should consist of removal of weak, dead or diseased wood, crossing branches, and for reduction in size or shape.      Always make your cut to above a healthy bud or set or buds, and on an angle.
Conifers      Conifers require little training and practically no pruning except when grown as a hedge. With few exceptions, such as yew and Western Red Cedar, conifers do not grow well from old wood. If your cur back into mature wood new shoots will rarely develop and you will be left with bare stubs. Therefore, only cut conifers back to live, visible buds. Do not cut back into old wood: cut off damaged or misplaced branches completely rather then leaving a stump. If pruning is required to control spread, it should be done in spring or early summer by reducing the length of the thin new growth. You can simply pinch out the new growth. Conifers that produce tight growth in a formal shape can be clipped regularly to retard growth. Some conifers have candles, such as pine and spruce, and you can pinch the candles back for bushy growth, or remove all but the middle candle to promote height.
Flowering Shrubs      The general rule of thumb is to prune your shrub when it is done flowering. Shrubs that flower in the spring will sometimes set new buds and flower again later in the season. Any major pruning can be done during dormant season. Some shrubs will not flower the next season if pruned to late (rhodos) because they do not have time to set new buds. If your shrub blooms on old wood only (forsythia, some hydrangea etc.) you will not get flowers the next season if you prune it back too hard.
Vines      Be aware whether your vine flowers on old or new wood or both. This will determine how you prune. If they bloom on new wood only, then you should prune it back to about 18" above ground level if you want it covered in flowers. If it blooms on new and old, you can let it grow and just prune to keep it tidy. If it only blooms on old wood, then cutting back to hard will reduce the amount of blooms the following season. Most vines should be pruned in spring. Some need maintenance pruning all season long (wisteria)!
Fruit Trees
APPLES AND PEARS Time to Prune - Mid-late winter or early spring Fruiting Habits and Pruning Tips Apples Most apples are 'spur bearers', fruiting on wood that is in it's third year or older, in the form of short, fruit-bearing shoots known as spurs. Their main branches are fairly evenly and well clothed with flower buds, spurs and new shoots. However, some cultivars produce clusters of fruit at or near the tips of longer shoots, with far fewer spurs and greater lengths of bare wood between the buds and shoots. These are known as 'tip bearers', although these varieties aren't as common. The routine winter pruning of spur-bearing varieties consists of shortening laterals to stimulate short fruiting side shoots. Growth from these will in turn be shortened, thus building up the familiar, knobby spur systems. Tip-bearers should not be spur-pruned since it will remove the wood on which fruits form. Instead, each year cut back a portion of older fruited shoots, either completely or to one or two buds, leaving the remainder unpruned to bear the crop for that year. After these shoots have borne fruit for a few years, they are removed in favor of the new growth stimulated by the pruning cuts on other shoots. All trees should have dead or weak wood removed, as well as crossing branches and excess branches in the middle of the tree. Pears Pears grow in a similar way to apples and also fruit on two-year old and older wood. However, a typical pear three has a more upright growth habit than most apples, and has a natural tendency to for spur systems. Without regular thinning, these tend to become overcrowded.
STONE FRUITS - PLUM, CHERRIES, PEACH AND NECTARINES Time to Prune - Stone fruits are prone to contracting disease if pruned in winter, therefore, early spring and/or mid to late summer is the best time to prune. Fruiting Habits and Pruning Tips Plums Plums fruit at the base of one-year old shoots and along the length of older wood. In mid to late summer, once the new growth has ceased, cut all the current season's side shoots back to 6" on an established tree. Also remove any very vigorous upright shoots, or any badly placed crossing or inward pointing branches. Cherries Like plums, cherries fruit at the base of the previous season's shoots and on older wood. In early spring cut back some of the old shoots to young side shoots produced the previous summer. This will ensure that some of the oldest wood is constantly being replaced. Peaches and Nectarines Peaches and nectarines fruit on shoots that grew the previous year. The aim of pruning therefore, is to remove fruited growth and encourage new shoots. When pruning to induce a new shoot, take care to cut to a pointed growth bud, not to plump flower bud. Spring is a great time to rub of excessive buds, and summer after fruiting is a good time to cut back each fruited shoot to it's replacement shoot.
Small Fruits
Blackberries, Boysenberries, Loganberries, and Tayberries These fruit best on one year-old stems, so, in winter, cut back to ground level all the old stems that have fruited, then tie in the young shoots produced the previous summer. Raspberries Summer fruiting raspberries carry their fruit on year-old stems. In the winter, cut out all those canes that have fruited, then tie in the new canes produced during the summer. If in time the clumps become congested, thin the canes to about 3in apart. Autumn fruiting raspberries carry their fruit on the current season's growth, so cut all the canes down to ground level during winter. Gooseberries After harvest, remove any badly placed branches, or crowding the center. In winter, reduce the length of the summer growth from the tips of the main branches by half, and reduce the side shoots, which produce the fruit, to two buds from the old wood. Also remove any weak, damaged, diseased or dead wood. Blueberries Do not prune for 3 or 4 years after planting, as they fruit best on wood that is 2 or 3 years old. Once well established, prune in early spring each year to stimulate plenty of strong new growth from the base. Blueberries require an acid soil. Black Currants On established plants, in winter, cut about one shoot in three each year. Concentrate on removing the oldest branches and those which are badly placed, cutting them back as low as possible. Red and White Currants On an established bush, cut out one main branch each winter taking it back to one bud above ground level. If site is windy, reduce the height of the bush. Grapes The first two years, train your main framework, according to the method you choose. In subsequent years, tie in your new side shoots. At the end of the growing season, cut back the side shoots to within two buds of the main stem, leaving stubs called spurs which will fruit next year.