← Diseases

Witches' Broom

Taphrina wiesneri

195 host plants

When you spot abnormal branch growth that resembles a broom or bird's nest on cherry, hazelnut, or juniper in the Puget Sound region, you're likely seeing witches' broom. The infected branch produces many short, slender twigs packed densely together, creating a distinctive dense tuft that stands out against normal branching patterns. These brooms rarely set fruit and have fewer flowers than healthy branches. The base of the broom is swollen and thicker than the normal branch, making it easy to trace where the infection begins.

This disease is incurable once established in a branch, so your only real option is removal. Trace the main stem of the broom back to where it emerges from the normal branch, then cut at least 12 inches below that point to remove all infected tissue. Make the cut into healthy wood to prevent regrowth from an infected stump. Pruning out brooms early before they spread to new branches keeps the problem manageable and preserves tree structure and fruit production.

Host Plants (195)

Corylus americana American Hazel, American Filbert
Corylus avellana Common Filbert
Corylus chinensis Chinese Hazel
Corylus colurna Turkish Hazel
Corylus cornuta var. californica Western Hazel, California Hazel, Western Beaked Hazel
Corylus heterophylla Siberian Hazelnut Asian Hazel
Juniperus californica California Juniper, California White Cedar, Desert White Cedar
Juniperus cedrus Canary Island Juniper
Juniperus chinensis Chinese Juniper
Juniperus communis Common Juniper
Juniperus conferta Juniperus conferta
Juniperus deppeana Alligator Juniper, Checkered-bark Juniper
Juniperus formosana Formosan Juniper
Juniperus grey Juniperus grey
Juniperus horizontalis Creeping Juniper
Juniperus monosperma Oneseed Juniper
Juniperus occidentalis Western Juniper
Juniperus osteosperma Utah Juniper
Juniperus pingii Ping Juniper
Juniperus procumbens Japanese Garden Juniper, Bonin Island Juniper, Ibuki Juniper
Juniperus rigida Temple Juniper, Needle Juniper
Juniperus rigida subsp. conferta Shore Juniper
Juniperus sabina Savin Juniper
Juniperus scopulorum Rocky Mountain Juniper
Juniperus squamata Singleseed Juniper, Flaky Juniper, gao shan bai
Juniperus virginiana Eastern Redcedar Pencil Cedar
Prunus americana Wild Plum American (Red) Plum August Plum, Goose Plum
Prunus armeniaca Apricot
Prunus avium Sweet Cherry
Prunus besseyi Sand Cherry, Western Sand Cherry
Prunus blireiana Blireiana Plum
Prunus caroliniana Carolina Cherrylaurel American Cherrylaurel
Prunus cascade Prunus cascade
Prunus cerasifera Cherry, Plum
Prunus cistena Purpleleaf Sandcherry Redleaf Sandcherry Cistena Sandcherry Cistena Plum
Prunus dream Prunus dream
Prunus emarginata Bitter Cherry, Wild Cherry, Quinine Cherry
Prunus first Prunus first
Prunus fruticosa Steppe Cherry, European Dwarf Ground Cherry, Mongolian Cherry
Prunus glandulosa Dwarf Flowering Almond
Prunus ilicifolia Hollyleaf Cherry, Holly-leaved Cherry
Prunus laurocerasus Cherry, Laurel
Prunus lusitanica Portugal Laurel
Prunus maackii Amur Chokecherry Amur Cherry, Manchurian Cherry
Prunus mume Japanese Apricotc Japanese Flowering Apricot Japanese Flowering Plum
Prunus newport Newport Flowering Plum
Prunus okame Okame Flowering Cherry
Prunus padus European Birdcherry Common Birdcherry
Prunus prostrata Rock Cherry, Mountain Cherry
Prunus sargentii Sargent Cherry, Sargent's Cherry
Prunus serotina Black Cherry, Rum Cherry
Prunus serrula Birchbark Cherry, Paperbark Cherry, Tibetan Cherry
Prunus serrulata Japanese Flowering Cherry
Prunus snow Prunus snow
Prunus subcordata Klamath Plum, Sierra Plum, Pacific Plum
Prunus subhirtella Higan Cherry
Prunus subhirtella var. autumnalis Autumn Flowering Higan Cherry
Prunus tai Prunus tai
Prunus virginiana Prunus virginiana
Prunus virginiana var. demissa Western Chokecherry
Prunus virginiana var. virginiana Common Chokecherry, Eastern Chokecherry
Prunus yedoensis Yoshino Cherry, Somei-yoshino Cherry, Tokyo Cherry
Rhododendron 'Purple Gem' Purple Gem Rhododendron
Rhododendron airy Rhododendron, airy
Rhododendron alabamense Alabama Azalea
Rhododendron alice Alice Rhododendron
Rhododendron anah Rhododendron, anah
Rhododendron anna Rhododendron, anna
Rhododendron april Rhododendron, april
Rhododendron arboreum subsp. cinnamomeum Cinnamon Rhododendron
Rhododendron argosy Argosy Rhododendron
Rhododendron augustinii Augustine Rhododendron
Rhododendron auriculatum No common name (R. auriculatum)
Rhododendron beauty Rhododendron, beauty
Rhododendron bibiani Bibiani Rhododendron
Rhododendron blue Rhododendron, blue
Rhododendron boule Rhododendron, boule
Rhododendron bow Rhododendron, bow
Rhododendron bric Rhododendron, bric
Rhododendron bureavii Bureau Rhododendron
Rhododendron campylocarpum subsp. coloxanthum Coloxanthum Rhododendron
Rhododendron catawbiense Catawba Rhododendron
Rhododendron cheer Cheer Rhododendron
Rhododendron chevalier Rhododendron, chevalier
Rhododendron christmas Rhododendron, christmas
Rhododendron cinnabarinum Cinnabar Rhododendron
Rhododendron concinnum Concinnum Rhododendron
Rhododendron cotton Rhododendron, cotton
Rhododendron crater Rhododendron, crater
Rhododendron crest Crest Rhododendron
Rhododendron cunninghams Rhododendron, cunninghams
Rhododendron cynthia Cynthia Rhododendron
Rhododendron daphnoides Daphnoides Rhododendron
Rhododendron dauricum Dauricum Rhododendron
Rhododendron davidsonianum Davidsonianum Rhododendron
Rhododendron day Rhododendron, day
Rhododendron deciduous Rhododendron, deciduous
Rhododendron defines Rhododendron, defines
Rhododendron delaware Rhododendron, delaware
Rhododendron dora Rhododendron, dora
Rhododendron dreamland Dreamland Rhrododendron
Rhododendron el Rhododendron, el
Rhododendron elisabeth Rhododendron, elisabeth
Rhododendron elizabeth Elizabeth Rhododendron
Rhododendron falconeri subsp. falconeri Falconer Rhododendron
Rhododendron fantastic Fantastic Rhododendron
Rhododendron formosum var. formosum Formosum Rhododendron
Rhododendron forrestii subsp. forrestii Forrest Rhododendron
Rhododendron fortunei subsp. discolor Fortune Discolor, Discolor Rhododendron
Rhododendron frilly Rhododendron, frilly
Rhododendron gartendirektor Rhododendron, gartendirektor
Rhododendron girards Rhododendron, girards
Rhododendron goldflimmer Goldflimmer Rhododendron
Rhododendron grace Rhododendron, grace
Rhododendron groenlandicum Labrador-tea, Labrador Tea
Rhododendron haematodes subsp. haematodes Haematodes Rhododendron
Rhododendron hallelujha Hallelujah Rhododendron
Rhododendron hanceanum Hanceanum Rhododendron
Rhododendron hardijzer Rhododendron, hardijzer
Rhododendron harry Rhododendron, harry
Rhododendron hino Rhododendron, hino
Rhododendron hinode Rhododendron, hinode
Rhododendron hippophaeoides var. hippophaeoides Hippophaeoides Rhododendron
Rhododendron hodgsonii Hodgson Rhododendron
Rhododendron honourable Rhododendron, honourable
Rhododendron horizon Rhododendron, horizon
Rhododendron hotei Hotei Rhododendron
Rhododendron irroratum Irroratum Rhododendron
Rhododendron jock Jock Rhododendron
Rhododendron johnstoneanum Rhododendron, johnstoneanum
Rhododendron keiskei Keiskei Rhododendron, Keisuki Rhododendron
Rhododendron ken Rhododendron, ken
Rhododendron kiusianum Kiusianum Azalea, Kyushu Azalea
Rhododendron lacteum Lacteum Rhododendron
Rhododendron lees Rhododendron, lees
Rhododendron lems Rhododendron, lems
Rhododendron lights Rhododendron, lights
Rhododendron loderi Rhododendron, loderi
Rhododendron luteiflorum Luteiflorum Rhododendron
Rhododendron lutescens Lutescens Rhododendron
Rhododendron luteum Pontic or Pontica Azalea
Rhododendron macabeanum Macabeanum Rhododendron
Rhododendron macrophyllum Pacific Rhododendron
Rhododendron moonstone Moonstone Rhododendron
Rhododendron mrs Rhododendron, mrs
Rhododendron mucronulatum Rhododendron, mucronulatum
Rhododendron myrtifolium Myrtifolium Rhododendron
Rhododendron niveum Niveum Rhododendron
Rhododendron northern Rhododendron, northern
Rhododendron occidentale Western Azalea
Rhododendron orbiculare subsp. orbiculare Obiculare Rhododendron
Rhododendron orchid Rhododendron, orchid
Rhododendron oreotrephes Oreotrephes Rhododendron
Rhododendron oudijks Rhododendron, oudijks
Rhododendron pachytrichum Pachytrichum Rhododendron
Rhododendron peekaboo Peekaboo Rhododendron
Rhododendron pink Rhododendron, pink
Rhododendron pioneer Rhododendron, pioneer
Rhododendron pjm P.J.M. Rhododendron
Rhododendron point Rhododendron, point
Rhododendron ponticum Rhododendron, ponticum
Rhododendron president Rhododendron, president
Rhododendron prinophyllum Roseshell Azalea, Pinkshell Azalea
Rhododendron prunifolium Plumleaf Azalea
Rhododendron quinquefolium Quinquefolium Azalea
Rhododendron racemosum Racemosum Rhododendron
Rhododendron ramapo Ramapo Rhododendron
Rhododendron rosamundi Rosamundi Rhododendron
Rhododendron roseum Rhododendron, roseum
Rhododendron rosy Rhododendron, rosy
Rhododendron roxieanum var. oreonasters No common name
Rhododendron rubiginosum Rubiginosum Rhododendron
Rhododendron sappho Sappho Rhododendron
Rhododendron scarlet Rhododendron, scarlet
Rhododendron schlippenbachii Royal Azalea
Rhododendron serpyllifolium Wild Thyme, Azalea
Rhododendron serpyllifolium var. albifolrum White Wild Thyme, Azalea
Rhododendron sinofalconeri Sinofalconer Rhododendron
Rhododendron sinogrande Sinogrande Rhododendron
Rhododendron smirnowii Smirnow Rhododendron
Rhododendron snow Rhododendron, snow
Rhododendron stenopetalum Rhododendron, stenopetalum
Rhododendron taurus Taurus Rhododendron
Rhododendron temple Rhododendron, temple
Rhododendron thomsonii subsp. thomsonii Thomson Rhododendron
Rhododendron tri Rhododendron, tri
Rhododendron trilby Trilby Rhododendron
Rhododendron unique Unique Rhododendron
Rhododendron vulcan Vulcan Rhododendron
Rhododendron wardii Ward Rhododendron
Rhododendron white Rhododendron, white
Rhododendron wiltonii Wilton Rhododendron
Rhododendron winsome Winsome Rhododendron
Rhododendron yakushimanum Yak Rhododendron
Solanum aviculare Kangaroo Apple