Root Rot (Phytophthora spp.)
Phytophthora spp.
176 host plants
Last updated
Data Coverage 3 of 6 dimensions
Phytophthora species cause root rot on many hosts, resulting in wilting and plant death. Improve drainage in affected areas. Remove infected plants. Rotate to new land or select resistant varieties. Avoid planting in poorly drained locations. Proper drainage and good site selection are critical to prevent root disease problems. Monitor plants for early signs of decline or wilting Early detection and prompt management of symptoms help limit disease spread.
Root rots thrive in waterlogged soil, so drainage is your most important intervention. Avoid overwatering and ensure the planting site drains well. Remove severely affected plants to prevent spread to neighbors through root contact or contaminated soil. When replanting, choose resistant species or improve soil structure before putting anything back in the ground.
Quick Reference
Causal Agent
Phytophthora spp.
Host Plants
176
Management
Cultural Controls
- Integrate several cultural and/or chemical tactics to manage this disease. Plant only disease-free plants. Inspect and discard any incoming diseased nursery stock. Amend soils with composted sawdust or bark mulch to provide good aeration for roots. Plant in beds raised so that the top of the bed is at least 12 inches above the surrounding soil. Ame
- Plant healthy seedlings in soil known to be free of the organism. Do not plant in soil with poor drainage or in areas that receive drainage from roads. Prevent wounding at the base of trees or to roots from nearby construction or harvesting operations. Avoid extensive gardening (mulching and planting susceptible flowering plants) under cedar hedges
- Preventive measures are paramount. Plant no deeper than the tree grew in the nursery. Dogwoods have shallow root systems, and planting too deeply can mean the tree will fail to thrive. Dogwoods are understory trees, so plant where they will have at least partial shade. Provide supplemental water during the summer; water with a soaker hose 6 inches
- Do not overwater plants. Blue cultivars should be grown at a pH of 4.5 to 5.0 and pink cultivars at 5.5 to 6.0. Aluminum sulfate is needed for the blue color development but additions to the soil may tie up needed phosphorus. Provide good drainage for plants in beds, fields, or containers. Place containers on gravel beds (4 inches or more deep) to
- Do not overwater plants. Provide good drainage for plants in beds, fields, or containers. Place containers on gravel beds (4 inches or more deep) to allow drainage. Do not place containers on poly sheets; they can prevent containers from draining into soil and allow contaminated drainage water to spread from the base of one container to another. Av
Host Plants (176)
Adenium obesum Desert Rose, Desert Azalea, Mock Azalea Menziesia ciliicalyx var. multiflora Mock Azalea, Menziesia Menziesia ferruginea Rusty Menziesia, Fool's Huckleberry, False Azalea Pinus albicaulis Whitebark Pine, Scrub Pine, White Pine Pinus aristata Bristlecone Pine, Rocky Mountain Bristlecone Interior Bristlecone Pinus attenuata Knobcone Pine Pinus banksiana Jack Pine, Scrub Pine, Banksian Pine, Hudson Bay Pine Pinus bungeana Lacebark Pine, Whitebark Pine, Baipi Song Pinus canariensis Canary Island Pine Pinus cembra Swiss Stone Pine Pinus contorta Lodgepole Pine Pinus contorta var. contorta Shore Pine Pinus contorta var. latifolia Rocky Mountain Lodgepole Pine Pinus coulteri Coulter Pine, Bigcone Pine Pinus densiflora Japanese Red Pine Pinus edulis Pinyon Pine, Piñón Pine, Two-needle Pinyon Colorado Pinyon Pinus elliottii Slash Pine, Swamp Pine Pinus flexilis Limber Pine, Rocky Mountain White Pine Pinus halepensis Aleppo Pine, Jerusalem Pine Pinus heldreichii Bosnian Pine, Snakeskin Pine Pinus jeffreyi Jeffrey Pine, Western Yellow Pine, Bull Pine Pinus kwangtungensis Kwangtung Pine, Guangdong Pine Pinus lambertiana Sugar Pine Pinus leucodermis Bosnian Pine Pinus monophylla Singleleaf Pinon Pine, One-leaved Pine Pinus monticola Western White Pine Pinus mugo Mugo Pine Pinus mugo var. pumilio Mugo pine, Dwarf Mugo pine Pinus nigra Austrian Pine Pinus parviflora Japanese White Pine Pinus parvifola Pinus parvifola Pinus pinaster Maritime Pine, Cluster Pine, Turpentine Pine Pinus pinea Italian Stone Pine, Umbrella Pine Pinus ponderosa Ponderosa Pine, Western Yellow Pine Pinus pumila Japanese Stone Pine, Dwarf Siberian Pine Pinus radiata Monterey Pine Pinus resinosa Red Pine Pinus sabiniana Gray Pine, Foothill Pine Pinus strobiformis Southwestern White Pine, Mexican White Pine, Chihuahua White Pine Pinus strobus Eastern White Pine Pinus sylvestris Scots Pine, Scotch Pine Pinus thunbergii Japanese Black Pine Pinus virginiana Virginia Pine, Scrub Pine, Jersey Pine Pinus wallichiana Himalayan Pine, Bhutan Pine Pinus yunnanensis Yunnan Pine 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 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