Fall Sanitation is
Important to Reduce the Amount of Disease Carryover
Gail Ruhl, Sr. Plant Disease Diagnostician, Dept.
of Botany & Plant Pathology, Purdue University
The parasitic fungi that cause leaf and fruit
spots, powdery mildew, cankers, etc. over-winter in the soil, in debris under the
plants, in cracks in the bark and in ‘mummified’ fruit. These
fungi wait in a dormant state until the following spring when rains
and warmer weather induce the production of spores which are then
disseminated by wind and rain to infect plants during the growing
Sanitation is one of the most important methods of
maintaining a healthy
garden. Removal of infected plant material will reduce the amount
disease causing fungi present in the area, thus reducing the amount
potential disease for the next season.
sanitation regiment for ornamentals, trees, shrubs, fruits, and
vegetables should include the following:
Prune out and destroy
all dead and diseased branches. Employ
proper pruning techniques. (pdf
Remove fallen leaves and fruit to eliminate them as an over-wintering
of plant pathogens and insects.
Remove dried, mummified, fruits or vegetables, old flower
heads and flower
stalks. This plant material should be composted, buried or
some other fashion when removed from the garden.
If plants were severely
infected, it is advisable to remove and destroy them.
Remove weeds. They
provide a winter habitat for fungi and insects, and seed for next year’s
In reality, sanitation is a year round process. Therefore,
infected leaves, flowers, fruit,and branches, as soon as problems
will reduce the spread of disease.
Click image to enlarge
Removal of foliage infected with black spot will
help reduce the amount of
Pre-sanitation--Note flower stalks and weeds that
will harbor diseases and
pests over the winter
Post Sanitation--Garden areas cleaned of plant debris
will provide an environment less
favorable to diseases and insects the following growing season.