Malus Trees

What’s the difference between an apple and crabapple tree?

All species within the genus Malus are crabapples with the exception of Malus domestica that are orchard apples. Orchard apples have been selected and bred for their large fruits. Today, crabapples are marketed as ornamental trees, providing year round colour with their blossom and fruits. However, they are great fruit trees in their own right, although like culinary apples, they are best cooked rather than eaten fresh.

What’s a species?

A species is a distinct population of organisms. Malus domestica is distinct from the Japanese crabapple Malus floribunda due to its genetic makeup. The modern orchard apple Malus domestica is descended from Malus sieversii, a wild apple native to central asia, the European crabapple Malus sylvestris, along with other wild apple species.

Why are crabapple trees excellent pollinators of apples?

Apple trees are made up of self-sterile and self-fertile trees. Self-sterile trees will not produce fruit without a compatible pollinator. For a tree’s blossom to be compatible it must fulfil 3 criteria: be substantially genetically different; not be a triploid tree, and flower at the same time.

Apple trees are divided into flowering groups. Apple trees in group 2 will always flower later than the trees in group 1, regardless of the weather. Due to the short flowering period, apple trees are unable to exchange pollen with trees +/-2 flowering groups.

Due to the different number of chromosomes, triploid trees are unable to pollinate other apple trees.

Genetically similar apple trees will not pollinate one another.

Crabapple trees are excellent pollinators as they are genetically different to orchard apples and have a long flowering period, with most varieties flowering first on spurs, followed by one-year old wood. It is recommended you plant a crabapple with similar colour blossom to that of apples (white with a touch of pink) as bees move between similarly coloured flowers.