Duo fruit trees are one of horticulture's greatest inventions; by grafting two separate fruit tree varieties (in this case, apple) onto a single, common rootstock, you essentially get two trees in one! 'Idared' and 'Braeburn' are two brilliant varieties in their own right, but pair them together and you get a dual-purpose powerhouse of an apple tree. Originating in Idaho in the 1940s, 'Idared' apples are dark red-skinned fruits that cook down into sauce well and that develop a milder taste the longer they're stored. First grown in New Zealand, 'Braeburn' apples have firm flesh that largely retains its structure when cooked, making them an excellent choice for pies and tarts. Both varieties are pollination partners, meaning they can fertilise one another, effectively making a self-fertile tree that saves on space.