The lingo of gardening is full of odd terms. A few that come to mind are deadheading, pricking out, pinching, and witches’ broom. The latter is not in every horticultural glossary, nor is it common knowledge, but it’s a very real thing. In defining the term, or even describing the abnormality, common words include disease, deformity, and even a place where a witch landed. To look up the term on “Google” you will have to scroll past the literal brooms of witches to get to any horticultural reference. 

Visually a witch’s broom is a tree or shrub branch that has developed a tight cluster of smaller branches. At first look you might think bee or squirrel’s nest. To some it’s a prized rarity, to others a threat to crops, specifically the brooms caused by a fungus that attack chocolate trees in tropical areas. 

There are eight different reasons for the tight forking of branches. Insects, fungi, virus, even solar radiation at high elevations can be responsible. A dwarf mistletoe which occurs in the northern states and Canada causes widespread brooming as it disrupts the growth hormones at the growing tips of trees. 

Of interest to those in horticulture are the cuttings and seeds from these anomalies when propagated. Cuttings will remain tight and dwarf, seeds will develop into variable offspring, even the cones on witch’s brooms are significantly smaller.  Many of the dwarf plants sold at nurseries began life as a broom, often with a name that reflects that i.e., Tsuga canadensis ‘Fantana Witch’s Broom’, Picea abies ‘Millstream Broom’, and Picea orientalis ‘Shadow’s Broom’. In this scenario the brooming can be financially beneficial, drawing witch broom hunters to popular areas, haunts like the Rocky Mountains, the Cascades, and central Europe. Some climb trees to harvest cuttings but many literally shoot them down, armed with rifles. 

In my lifetime I have only found three. The largest of my three sightings was in a cedar or Juniperus virginiana in the cemetery in Upperville, VA, located on route 50. I watched it for years, a sizable broom. Eventually the juniper was cut down and disposed of and it’s unlikely that the broom was propagated. The other two were on white pine, the result of a broom mite that injects saliva and creates adventitious buds (buds that emerge in areas they do not usually develop). One white pine broom was at the National Arboretum in Washington DC and the other in my own garden, only recently discovered. I see it as a gift, a prized freak of nature! All who visit are soldiered out to my tree, informed that they are about to see my witch’s broom. A nongardening friend was quick to comment that she had been waiting for this day, true to form and always the clever one, I think she was disappointed. It’s true, it won’t take me places, but I’m good with that.

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