stamväxling

Stamväxling, or trunk grafting, is a horticultural technique used to replace the cultivar on the main trunk of a woody plant by grafting a new scion onto the trunk. The aim is to change the cultivar present above the graft without removing the entire tree, allowing continued use of established rootstock and roots. Stamväxling is commonly applied to fruit trees such as apples, pears, plums and some ornamentals, to renew aging trees, improve fruit quality, introduce a new variety, or adapt a tree to market demands.

The procedure relies on successful cambial contact between the stock and the scion. It is typically performed when the tree is dormant and the bark can be separated from the wood more easily. Several graft forms can be used on the trunk, including shield grafts (sköld ympning) and other cambial-contact methods. A scion with a few buds is prepared and attached to the trunk in a way that aligns the cambial layers, then secured with grafting tape or ties and sometimes sealed to reduce moisture loss while healing.

Aftercare is important for a successful union. The graft area should be protected from desiccation, sun, and extreme temperatures. Suckers from the rootstock should be removed to direct resources to the grafted area. The wrap is monitored and removed once the graft has established a strong callus and growth begins.

Effectiveness varies with species, age of the tree, and the skill of the practitioner. Stamväxling remains a valuable option in orchard management for renewing productive trees without full replanting, though not all trees or situations are suitable. Related topics include other grafting techniques and topworking.