→ View All
Spring Gardening Tips for a Flourishing Garden
As the vibrant colors of spring burst forth and the air fills with the sweet scent of blossoms, it's the perfect time to roll up your sleeves and tend to your garden. Whether you're a seasoned gar...
Chest of Hope
Listed under: Community Service & Support Crime & Justice
How to prevent the spread of this yucky fungal disease
Gray mold ruined this Gemini hybrid tea rose bloom. The fungus got just enough rain earlier this month to deface fall roses. Debbie Arrington
My visions of Thanksgiving bouquets are quickly turning to mush. Gray mold is attacking my roses.
Gray mold is the descriptive nickname of the fungal disease botrytis. It’s common in November rose gardens, and this season’s outbreak came early.
Damp conditions in early November gave gray mold a big boost. Gray mold – which actually looks more tan or brown on the rosebud – needs moisture for growth in plant tissues, particularly tender flower petals. And this month, the fungus got just enough rain to explode among my pretty fall roses.
Gray mold starts out looking like pink measles or brownish water spots on light-colored flowers. Those brown spots rapidly grow until the fungus consumes the whole petal and eventually the whole flower. The bud never fully opens.
Gray mold also attacks many other favorite flowers including African violet, aster, begonia, carnation, chrysanthemum, cyclamen, cymbidium, gerbera, geranium, gladiolus, hydrangea, marigold, orchid, petunia, poinsettia, primrose, ranunculus, snapdragon and zinnia.
According to UC Integrated Pest Management program, the best control of gray mold is “good sanitation.” Clip off infected blooms, put them in a plastic bag and dispose in the trash. Do not compost them; that just recycles the spores back into the garden.
Pick up fallen blooms and petals around the bush and dispose of them, too. After pruning when roses are dormant, rake out old mulch and fallen foliage. (This contains other fungal spores, too, for powdery mildew, rust, black spot and other rose diseases.) Dispose of that old mulch (again in the trash, not compost) and replace with fresh mulch.
Generally, I snip off buds infected with gray mold before they have a chance to drop. (That’s my game plan for spring botrytis outbreaks.)
But that strategy is problematic in mid-November. The bush needs its hips – the fruit located at the base of the blooms – to mature; that’s the plant’s signal to go into dormancy and shut down for the winter. If the spent flowers (and forming hips) are removed, the bush keeps on pushing out new growth. (That makes rose pruning in December and January a bigger pain.)
Master rosarian Dave Coop shared this tip on how to control botrytis while also allowing the hips to ripen. Instead of snipping off the spent bloom, gently pull off its petals. (Make sure to wear gloves when working with roses.) Discard the brown infected petals. The clean hip can then ripen, turning bright orange or red. And the bush can start shutting down for winter.
This method also helps control future fungal outbreaks. Instead of the botrytis-packed petals laying in wait under rose bushes, the gray mold is bagged up and removed from the garden; that will cut down on infections next spring – and later in the year, too. (Again, that’s “good sanitation.”)
For more information on gray mold, check out these pest notes from UC IPM: http://ipm.ucanr.edu/PMG/r280100511.html
Comments
An article about gardening.
Sacramento Digs Gardening to your inbox.
Taste Spring! E-cookbook
Find our spring recipes here!
Local News
Thanks to our sponsor!
Sites We Like
Garden Checklist for week of May 19
Temperatures will be a bit higher than normal in the afternoons this week. Take care of chores early in the day – then enjoy the afternoon. It’s time to smell the roses.
* Plant, plant, plant! It’s prime planting season in the Sacramento area. If you haven’t already, it’s time to set out those tomato transplants along with peppers and eggplants. Pinch off any flowers on new transplants to make them concentrate on establishing roots instead of setting premature fruit.
* Direct-seed melons, cucumbers, summer squash, corn, radishes, pumpkins and annual herbs such as basil.
* Harvest cabbage, lettuce, peas and green onions.
* In the flower garden, direct-seed sunflowers, cosmos, salvia, zinnias, marigolds, celosia and asters.
* Plant dahlia tubers. Other perennials to set out include verbena, coreopsis, coneflower and astilbe.
* Transplant petunias, marigolds and perennial flowers such as astilbe, columbine, coneflowers, coreopsis, dahlias, rudbeckia and verbena.
* Keep an eye out for slugs, snails, earwigs and aphids that want to dine on tender new growth.
* Feed summer bloomers with a balanced fertilizer.
* For continued bloom, cut off spent flowers on roses as well as other flowering plants.
* Don’t forget to water. Seedlings need moisture. Deep watering will help build strong roots and healthy plants.
* Add mulch to the garden to help keep that precious water from evaporating. Mulch also cuts down on weeds. But don’t let it mound around the stems or trunks of trees or shrubs. Leave about a 6-inch to 1-foot circle to avoid crown rot or other problems.
Taste Summer! E-cookbook
Find our summer recipes here!
Taste Fall! E-cookbook
Find our fall recipes here!
Taste Winter! E-cookbook
Find our winter recipes here!
You are subscribed!
Look for our confirmation message in your email inbox.
And look for our newsletter every Monday morning. See you then!
You're already subscribed
It looks like you're already subscribed to the newsletter. Not seeing it in the email inbox of the address you submitted? Be sure to check your spam folder or promotions folder (Gmail) in case your email provider diverted it there.
There was a problem with the submitted email address.
We can't subscribe you with the submitted email address. Please try another.