Advice
RHS Help & Advice
Choosing apples and pears
When choosing apple or pear cultivars several important factors need to be considered, including desired height, flowering time, continuity of supply and disease resistance.
Rootstocks
Growth rate of fruit trees can be manipulated by grafting the required cultivar onto a chosen rootstock.
There are many different rootstocks available for apples, slightly fewer for pears. The most widely available apple rootstocks are M27, M9 and M26 and M106, producing trees of between 1.5-1.8m (5-6ft), 2.4-3.6m (8-12ft) and 3.6-5.4m (12-18ft) tall respectively, whereas for pears Quince A (3-6m/10-20ft) is most frequently offered. Soil type also influences growth rate, with light sandy or chalky soils limiting growth more than clay-based ones.
Pollination
Although one or two apples and pears are classed as self-fertile the majority require pollen from a different cultivar of the same crop that flowers at the same time to set fruit. Different cultivars flower at different times and so flowering 'groups' have been identified. For sufficient pollination to occur both cultivars must be in the same or an adjacent flowering group. However, certain cultivars known as 'triploids' (such as 'Bramley's Seedling') are ineffective pollinators, and this must be taken into account. Additionally, there are some incompatibility groups with both apples and pears. Fruit in these groups are unable to set a crop either with their own pollen or with the pollen of any other cultivar within the same group.
Complete Adobe Acrobat pdf list of apple flowering and pollination groups (58KB)
Harvesting
Some apples and pears need to be eaten within a few weeks of picking, otherwise flavour and texture rapidly deteriorate, whereas others will store for many months. Consequently, careful consideration of individual harvest and storage times should be made.
The majority of apple and pear cultivars are either dessert or culinary, although some are dual purpose. For example, many cooking apples become sweeter on storage, lending themselves to dessert use as the season progresses.
Flavour is a very important consideration for most gardeners. Often cultivars available for sale in supermarkets are imported from warmer countries, and growing these in the UK proves disappointing. Organised autumn 'apple tasting' events are a useful way to determine particular favourites. The majority of fruit cultivars are developed by crossing two known parents and this allows the offspring to inherit certain flavour characteristics. Disease resistance is another important characteristic which varies between cultivars, with modern types often having higher levels of resistance than traditional ones.