Roses: Treat black spots now, look out for mites
If you grow roses that are susceptible to diseases and infestations, now is the time to start spraying weekly for black spot. There are several products that will work, including neem oil. For more information on black spot of rose and treatment options, go to edis.ifas.ufl.edu/ pdffiles/PP/PP26800.pdf.
If the leaves take on a dusty appearance or show signs of yellowing without black or brown spotting, check for spider mites or chilli thrips. Mites are a common problem on roses in the dry spring months. Chilli thrips are very hard to see. Feeding damage turns tender leaves and buds a bronze color. Damaged leaves curl upward and appear distorted, and the leaves will fall off the plant. Several products, including insecticidal soaps and oils can be used to control mites. For chilli thrips, use neem oil. As with all pesticides, follow the label directions carefully.
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The amount of maintenance needed for your roses varies according to the kind of rose you are growing. Most modern roses, hybrid tea and grandiflora roses need weekly watering and spraying, frequent grooming to remove old flowers, fertilization after each flush of bloom, and pruning and mulching in early spring. Low-maintenance roses such as Bourbon, China, Bermuda, Tea (not hybrid tea) and shrub roses typically require minimal maintenance. For more information on growing roses in Florida, go to edis.ifas.ufl.edu/pdffiles/EP/EP33900.pdf.
Source: Theresa Badurek, Urban Horticulture Extension Agent, UF/IFAS Pinellas County Extension Service. For additional landscape and garden information, visit their website at pinellascountyextension.org. Follow them on Facebook for regular tips and information about what's growing in Pinellas at: facebook.com/growpinellas.