Witches' Brooms 2015

Cady’s Falls Nursery

Don & Lela Avery

637 Duhamel Rd. Morrisville, Vt. 05661

Witches’ brooms are abnormal growths that appear in a wide range of woody plants and are frequently found in conifers. They can be caused by disease, physical injury or spontaneous bud mutations. It is the last group that has horticultural potential. Almost all of the dwarf and slow growing conifers in cultivation worldwide originated as seedlings or vegetative propagations from witches’ brooms. Many broom propagations are inherently weak and short-lived, but careful selection of healthy brooms by astute plantsmen, over many decades, has resulted in an abundance of garden-worthy plants, a few of which are shown below.

Dormant witches’ broom in Larix laricina in Montpelier Vt.

Above, a witches’ broom on Pinus mugo ‘Mops’ which was itself a broom propagation. Right, the broom growth, removed from the mother plant, when it was shaded out by larger trees and dug out of the garden in 2012.

Picea abies ‘Pusch’ originated as a witches’ broom on Picea abies ‘Acracona’ in Germany.

It produces an abundance of female flowers and cones on the tips of the branches.

Picea orienalis ‘Tom Thumb’ originated in New Jersey as a witches’ broom on P. orientalis ‘Skylands’.

Picea pungens ‘Ruslyn Blue Moon’ perhaps the smallest blue spruce in cultivation. Discovered in an abandoned Christmas tree plantation in NY state by Vern Palmateer. Extremely difficult to graft and very slow growing

Pinus banksiana ‘Black Duck’ in full candle, from a witches’ broom found in Corea, on the Maine coast, which had both male and female cones. Grown and selected at Cady’s Falls. Below, the original broom revisited in 2012.

Several disease-generated witches’ brooms in Picea glauca on the Bruce Peninsula, Ontario.

Larix laricina ‘Blue Sparkler’ sheared as a compact globe. This originated as a broom seedling on our native eastern larch and was selected by Syd Waxman, University of Conn.

Pinus strobus ‘Kerley #2’ A seedling from an old unnamed broom seedling which was pollinated by P.s.‘Contorta’. Selected by Greg Williams who recently discovered that contorted seedlings also have contorted roots.

Witches’ broom in Pinus strobus, Westfield Vt.

Pinus strobus ‘Verkade’s Witches’ Broom’ high-grafted and sheared in an umbrella form.

Picea glauca ‘Cecilia’ one of the all-time best dwarf conifers, from Greg Williams.

Witches’ broom in Pinus banksiana, Schoodic Maine.

Deciduous brooms, cause by a fungal rust pathogen, are commonly found on Abies balsamea. The needles emerge pale green in the spring, turn yellow in summer and fall off in early fall. The brooms are of no horticultural value.