How to Manage Pests
Pests in Gardens and Landscapes
Damping off and root dieback of carrots—Pythium spp.
Carrots infected with the Pythium fungus fail to emerge, or they fall over and die soon after
emerging. Stems usually have a dark, shriveled portion at the soil line. Pythium spp. may also
cause root dieback of carrots by producing excessively branched or stubbed roots. The fungus kills young
tap roots less than 2 weeks after seed germination, reducing root length and/or stimulating multiple root
Pythium is spread
in water and soil. Very wet soil conditions favor the disease.
Plant in light soils such as sandy loam. Maintain uniform
soil moisture at seed depth until seedlings emerge. Avoid
planting during high temperatures and keep soil as cool as possible when the weather is warm. Be sure seeds are
not planted too
deep. Protect soil surface from rain or sprinklers. Avoid overwatering and provide good
For more information, see the Damping-off
Diseases in the Garden Pest Note.
Roots of young carrot plants damaged by Pythium compared with healthy plant