Figure 29 shows the vine after pruning for a vase-formed head. The pruner has used two of the strongest canes to form two three-bud spurs and three of medium vigor to form three two-bud spurs. The head is of good shape, though some of the spurs are a little too low. One, two, or three of these can be removed at the following winter pruning, and the permanent arms and head of the vine formed from canes which develop on the two highest spurs. If the vine were too high, the head could be developed the next year from the three lowest spurs and the upper part removed. [Illustration: FIG. 30. Three-year-old vines: _A_, pruned for a vase-formed, and _B_, for a fan-shaped head.] Figure 30 shows vines of the same age of practically perfect shape. Less spurs have been left because the vines were less vigorous. It is easier to properly shape vines which make only a moderate growth during the first three seasons. On the other hand, very vigorous vines can finally be brought into practically perfect shape and the somewhat larger and more numerous wounds necessary are more easily healed by a vigorous vine. _Pruning after the third winter._ For the pruner who understands the pruning of young vines and has brought them to approximately the form represented in Figs. 29 and 30, the subsequent winter pruning is very simple. It involves, however, one new idea--the distinction between fruit and sterile wood. Up to the third winter pruning, this distinction is not necessary; first, because practically all the wood is fruit wood, and second, because the necessity of forming the vine controls the choice of wood. From this time on, however, this distinction must be carefully made. At each winter pruning a number of spurs of fruit wood must be left to produce the crop to be expected from the size and vigor of the vine. Besides these fruit spurs, it may be necessary to leave spurs of sterile wood to permit of increasing the number of fruit spurs the following year. This will be made clear by comparing Figs. 30 A and 31. Figure 30 A shows a vine at the third winter pruning with two fruit spurs of two buds each and one fruit spur of one bud--five fruit buds in all. If these five fruit buds all produce vigorous shoots during the following summer, they will supply five canes of fruit wood which can be used to form five fruit spurs at the following winter pruning, which will be about the normal increase necessary. Some of these fruit buds, however, may produce weak shoots or shoots so badly placed that they would spoil the shape of the head if used for spurs. Other shoots, however, will be produced from base, secondary and adventitious buds which, while less fruitful, can be used to form spurs for the starting of new arms. [Illustration: FIG. 31. Four-year-old vine pruned for vase-formed head.]