Fruit trees cannot be grown as the same variety from seed, so they are propagated by grafting the fruit variety onto a young tree called a rootstock.
Chip-budding is a commonly used technique which fits a section of young wood containing a bud onto a rootstock.
While the chip bud grows to form the new tree, the rootstock supplies water and nutrients to the growing shoot.
The grafted tree is then genetically identical to the fruit variety the graftwood was taken from.
By careful selection of rootstock, trees of different height and vigour can be grown.
Different methods of grafting have enabled growers to maintain varieties over hundreds of years.
The Sussex apple variety Mannington's Pearmain, for instance, is genetically identical to the original tree found growing from a pip in discarded apple pulp near Uckfield in the 1770s.
If you would like to learn how to graft trees yourself, we run yearly courses in chip budding.
The tutor Peter May has a background in commercial horticulture and community orchard projects. He grows Sussex apple varieties on his fruit tree nursery near Cooksbridge. You can watch Peter demonstrate chip budding in this short video.
Find out more about our Fruit tree grafting course.