Old Garden Rose in a Vase provided by Lilian Perry.
Rose Diseases!
Major diseases of roses, as with insects, identification is key importance to
treatment.  We have listed some of the most common rose diseases to help
identify, recognize the cycles of diseases and how to control them.
Please read directions before using any fungicide.
DISEASE
SYMPTOM
CONTROL
Powdery Mildew - fungas
A slightly raised blistered on
upper leaf, later leaves
become twisted and
covered with a white
powder mass.
Dormant pruning and
cleaning up old leaves,
sanitation is best
control.Spray Triforine or
Immunox, dust with
sulphur or spray with
baking soda and soap.
Blackspot - fungas
Small black spots in
circular appearance on
leaves, later defoliation.
Dormant pruning, removal
of attached leaves and
cleaning up old leaves, well
aerated site, do not
overhead water roses, In
winter us dormant
lime-sulphur spray, spray
with Neem oil, Daconil,
Immunox, Systemic sprays
during growing season.
Downy Mildew - fungas
Young leaves, stems and
flowers may have purple to
red or brown irregular
spots, later lesions on
leaves become angular and
black with white powder on
underside of leaf.
Good ventilation, removal
of all dead leaves around
the bush and on the bush.  
Use Daconil, Immunox,
and Systemic sprays during
growing season.
Rose Cankers - fungas
Cut stems provide wound
sites for yellow, often have
red spots and later become
brown or black.  
Removal of dead canes,
make angular cuts, spray
with Immunox, Daconil,
Systemic sprays during
growing season.
Rust - fungas
Occurs during cool and
moisture weather, appears
as orange to rust colored
spots on leaves, usually
close to the ground.
Removal of all leaves from
around the base of plants
and pruning out canes that
have infections, use same
spray program as
black
spot.
Crown Gall - bacteria
Overgrowths at the crown,
bud union or on the roots,
spongy feel,
Remove the rose bush and
all the soil surrounding the
bush
Rose Mosaic - virus
Leaves will appear to be
wavy and have yellow  
lightening patterns, oak leaf
patterns or simply gold to
yellow veins.  
Remove the rose bush and
all the soil surrounding the
bush.
For more information visit the American Rose Society.
Rose Leaves with Powdery Mildew
Rose Leaves with Blackspot
Rose Leaves with Blackspot
Rose Leaves with Blackspot
Disclaimer:   While the advice and information contained in this web page is believed to be true and correct, neither the authors nor board members
can accept any legal responsibility for any errors or omissions that may have been made. The Oklahoma Rose Society makes no warranty,  
expressed or implied with respect to the material contained herein
Oklahoma Rose Society