Consulting Rosarian Tips for August:
In this year of unusual weather events
and record rainfall amounts, it is important to get yourself out of
Noah’s Ark long enough to enjoy your gardens, as well as keep a
careful eye on what is happening in them. I’m surprised how well
some of my roses are thriving; but I also realize all this rain may
produce some issues we don’t usually see.
This year, we may see more blackspot and
rust than we need to admit to the rest of the country. Watch the
lower leaves of your plants; pull off infected leaves and be
prepared to spray with GreenCure, Serenade or other fungicides.
Higher humidity will probably mean more powdery mildew on newer
leaves and buds. August and September are often our prime disease
Believe it or not though, you need to
check for water needs! Even with some rain 11 of the past 12 days in
my yard, I was surprised how dry the garden soil was, particularly
beneath the leaf canopies.
As you deadhead spent flowers, check
inside the plant for places you can thin out errant and unproductive
growth. Sun access and good airflow throughout the plant can help
the rose thrive and hold down insect pests and disease. Concentrate
the growth on good canes for more flowers.
Apply your final round of fertilizers by
the middle of August. You’ll get plenty of flowers this fall, and
the rose will have a chance to use the nutrients, then slow down and
harden off before the hard winter freezes set in. I like to water
the plants the day before, then apply fertilizer and water again, to
moisten organics, and move liquids down into the root zone.
As August winds down, keep an eye on
more tender roses like Hybrid Teas and Floribundas. If they send out
new growth from the base of the plant (known as basal breaks), that
new growth will have no chance of surviving the winter, and will
drain the plant of energy, even if it flowers. So snap off the basal
breaks, and let the rose bloom its head off on established wood.
Japanese beetles should begin to wind
down this month – until then, toss them in soapy water and let them
suffer and drown. Watch for thrips – spinossad is a possible organic
control, or mist insecticide only on the unopened blooms (to protect
For rose questions, contact
Rosarian in your area.
Roses in Review
Every year, the American Rose Society
conducts a survey of roses and how they grow in gardens around the
nation. We need rose growers in the Rocky Mountain District
(Colorado, Wyoming, Idaho, Montana, Utah and Calgary) to provide
input. Go to the RIR tab at
Rose.org by September 26th.
You do not have to be an ARS member to provide input. Results
will be available in the fall.
The book, Growing
Roses in Colorado, published
by the Denver Rose Society is a "must have" for those who want to grow beautiful
Get a glimpse
Growing Roses in Colorado.
Available at area garden retailers and gift shops. For
wholesale inquiries please contact Betty Cahill at
Retail locations that sell the