Most amateurs are confused by the choice of apple rootstocks, but with pears the situation is pleasingly straightforward because in effect there is at present only one suitable rootstock. The history of rootstocks for pears is interesting. In the early years of fruit husbandry pear varieties were grafted on to the root systems of seedling wild pears. The wild pear still grows in the West Midlands, where it makes a very large spectacular tree. Naturally, the cultivated varieties when grafted on to seedling pears also grew into very large trees, slow to bear and difficult to manage. Some horticultural genius then thought of uniting the pear varieties with the root system of a close relative, the quince, which is much less vigorous in growth.
Pears on quince make small compact trees, which come into bearing in, say, five years after planting. Not all pear varieties unite successfully with the quince tissue. For example, the excellent William’s is incompatible. This, and a few others, are propagated by a technique known as double-working, which ensures a strong union of tissue with the advantages of the quince rootstock.
Although there are a number of selected clonal quince rootstocks the only one used at present to any extent is that known as Quince A. This gives excellent results, but some of the more vigorous or shy-fruiting varieties require a rootstock with rather less natural vigour. To meet this need the East Mailing Research Station has recently re-selected another clone, distinguished as Quince c, and varieties worked on this rootstock should be available for planting by amateur gardeners before long.
It is likely that Quince c will be ideal for gardens, and particularly for the variety Doyenne du Cornice, but meanwhile we can with confidence plant trees grown on the well-tried Quince A.
Insist on trees worked on certified root-stocks, and ask for the very best in the form of EMLA quince A or c rootstocks when these become generally available.
Great care should be taken not to plant too deeply. It is essential to keep the union— the swollen piece on the main stem at which the pear variety was grafted (or budded)— well abovelevel. If the union is buried then there is a risk that the pear variety will produce its own roots. If this occurs the weaker quince root system will be dominated and the character of the tree will revert back to the undesirable habit of the very vigorous pear. A good guide is to plant the young tree to the soil mark on the stem, which indicates the depth at which the tree was planted in the nursery.