Witches’ Broom Collection

Witches’ Broom Collection

A witch's broom is a mutant characteristic of some plants, including coniferous evergreens and deciduous shrubs and trees. It is an abnormal growth of dense, darker green foliage near the truncated branches that gather into a form similar to representations of witches' brooms. They can be created by natural mutation, a parasite, or a virus that causes the growth to take on a stunted appearance. 

The growths can be removed from the tree and propagated as cuttings, or, in ideal conditions, they mature enough to bear seeds, which are harvested and propagated to spectacular effect. One of the evergreens in this collection, the native eastern larch (Larix laricina), was propagated from a witch's broom cutting. 

In 1980, noted University of Connecticut horticulturist Dr. Sidney Waxman donated 12 broom seedlings to the Arboretum's collection, all from mutant white pine (Pinus strobus). Dr. Waxman gave his plants whimsical names such as P. strobus 'Sea Urchin.’ Today, they have matured into small shrubby evergreens. Note the shorter needles and truncated spaces between the whorls of needles.