Battles with black spot can be victories in your garden
Published 6:25 pm Saturday, April 5, 2008
It’s a battle. Black spot is trying to ravage roses now that humidity and temperatures are on the rise. I am determined to stop it.
This is a new battle for me. Gardening in Los Angeles was a breeze compared to combating Southern humidity and diseases. Yet, it’s worth it to me to try to conquer black spot for it is just a small price to pay for the many, many benefits of living in Natchez. Black spot was rare in my Los Angeles garden. However, there were other fungal diseases that attacked — mildew in spring and rust in spring and fall.
The simplest way to beat black spot is to grow roses that have inherent immunity. By now, most gardeners have learned about Knock Out roses. Yes, these shrub roses shrug off black spot fungal spores. Their leaves can be spotted in the worst of humidity, heat and rains. But the bushes won’t drop all leaves and will keep blooming until late fall.
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My garden on Linton Avenue is both a display and a test garden. Rose breeders send me their creations to test and observe for disease resistance. For the first two years here, I was asked to grow the roses without spraying them to fight fungal diseases or insects. So I have been able to see, close up and personal, which roses fight off black spot without any assistance.
My hands-down favorite is a little known variety, Yellow Submarine, by an up-and-coming rose breeder, Ping Lim. This talented and enthusiastic lover of all things rose hybridizes for Bailey Nurseries, a family run 100-year-old wholesale nursery in Minnesota. He has created a complete line of very disease-free roses which Bailey sells as Easy Elegance. I have tried seven different varieties and my favorite is Yellow Submarine. Growing upright, with bright yellow flowers that hold their color even in summer, this floribunda had absolutely no black spot on any of the three bushes in my garden. Bushes on either side did have some, so it wasn’t a matter of location.
He’s also created an AARS winning variety, Rainbow Sorbet, which shows remarkable black spot resistance. I love its two-toned flowers in hues of pink and yellow.
Little Mischief is another exceptional variety. A large shrub with many clusters of tiny pink flowers, this is an excellent variety for landscape display. I will be testing a new variety this year, Super Hero, reputed to have outstanding black spot resistance with red roses in hybrid tea form. This will be a valuable addition for those who love hybrid tea roses and I will keep you informed.
My other black spot-free star in my garden is Home Run, an offspring of Knock Out, created by Tom Carruth, director of research for Weeks Roses in California. I prefer Home Run to the Knock Out series because I love its vivid Chinese lacquer red flowers with bright yellow stamens. It’s a very pretty plant with nice rounded shape. It’s usually the first to flower and the last to quit of all the roses in my garden. You can see a mass planting at Stanton Hall, near the swimming pool. The bed also contains a lovely climbing rose, Fourth of July, and yellow floribunda Livin’ Easy. Both have good black spot resistance.
For those of you who are growing roses which will be affected by black spot, it is necessary to spray them with a fungicide specially formulated for black spot. There are sections of my garden that I am spraying, and I am careful to use the least toxic products that won’t harm beneficial insects. Rose Rx, which is also an insecticide and miticide, is proving effective. The main ingredient is neem oil which is gentle on the environment and the person doing the spraying. It’s available from EdmundsRoses.com.
For information about Easy Elegance roses, see www.baileynurseries.com. For information about Home Run, see www.weeksroses.com.
Karen Dardick writes a monthly rose column for The Democrat. She can be reached at firstname.lastname@example.org.