The Bramley crops well, but the other apple tree never produces a thing. This is not an uncommon complaint. It’s usually the tree that has failed to fruit that is identified as the ‘problem’. In fact, the ‘culprit’ will almost certainly be the Bramley. Bramley’s Seedling is triploid. The trouble with triploids is they have no viable pollen and cannot be used to pollinate other apple trees. Triploid apple varieties are mostly self-sterile and need to be pollinated by another compatible apple or crab apple. However, they don’t return the favour. This means if you are a planting a Bramley or other triploid variety, you will need another apple cultivar that is self-fertile that can pollinate itself and the triploid. Alternatively, you can plant two varieties that are able to cross-pollinate each other as well as the Bramley. Granny Smith, Golden Delicious and Braeburn are all varieties that are compatible pollinators for Bramley’s Seedling. So what is triploid? Most plants and animals, including humans, are diploid – that is they have two sets of chromosomes that they have inherited from their parents. Triploids have an extra set of chromosomes that makes them difficult to pollinate. Some very popular apple varieties are triploid such as Ashmead’s Kernel, Blenheim Orange and the American apple Jonagold. So why when they have such an obvious drawback does anyone go to the trouble of growing them? Triploids do have a number of important advantages. They are usually vigorous trees that produce large apples that crop well. In general, they have good resistance to disease and can tolerate difficult growing conditions.