The wild crab apple, Malus sylvestris, is fruiting at the moment, and cultivated varieties are now available to order from fruit nurseries.
This is one I saw at RHS Wisley recently, Malus transitoria.
Although they are members of the apple family, they are pretty unpalatable raw and usually made into preserves, so might not be seen as worth growing in a smaller garden where space is limited. But it’s a shame to overlook their ornamental potential, with blossom in spring, colourful fruit (also providing an autumn and early winter food for birds) and the attractive foliage of some varieties.
Like apples, they are grafted onto rootstocks which control their vigour and eventual size, so they can be a perfect choice for a small garden. I’ve just ordered ‘Laura’, a naturally dwarf variety with a purplish tinge to its foliage, apparently especially suitable for growing in a pot.
This is another from RHS Wisley, Malus yunnanensis.