Rose Report

What to do (and not do) in the August Rose Garden

Hey John, “Should I fertilize my roses in August?”

Yes, you may use the fertilizer that your soil test recommended. Although my test results said to add only nitrogen, at this time of year, I go astray and apply an organic fertilizer like fish emulsion or a seaweed-based product. There is time left in the season for the products to break down so the roses can use the nutrients. These are typically a balanced fertilizer (about equal parts of nitrogen (N), phosphorous (P) and potassium (K)). They also provide micro-nutrients for which you may not have tested. The end of August should be your last fertilizer application for the year. As we get into fall, the roses are preparing to go dormant and do not want to be stimulated. Be sure to keep up your watering schedule of at least an inch per week.

Hey John, “Should I treat my lawn for the $%&@ Japanese Beetles?”

Yes, treat your lawn and all your neighbors’ lawns. Japanese Beetles have about a five-mile range, so you will be treating a lot of lawns. After the adult beetles feed on your roses and mate (they do this at the same time), they lay their eggs in your lawn. The eggs hatch in July and August, and the grubs begin feeding. At this time of year, they are not deep in the lawn, so an insecticide is effective in killing them. While you can’t really treat everyone’s lawn, I say every little bit helps. Any lawn insecticide that is labeled for grubs will be effective.

Hey John, “What do you mean when you say deadheading?”

Deadheading is the removal of spent blooms. Removal encourages the rose to create a new bloom. If the bloom is left on the plant, the pollinated flower will produce a hip, which is the rose seed pod. Making seeds takes away energy from bloom making. For roses with a single bloom, you will want to cut the cane about ¼ inch above an outward facing five-leaflet leaf. You may select the first one below the bloom, or cut a lower one as needed to shape the bush. For a spray of blooms, like you may find on a floribunda, cut the individual blooms as they fade, and leave the remaining nice blooms. Cut where the base of the flower joins the stem. When the entire spray is spent, cut off the entire spray like you would a single bloom. Continue deadheading through September. After that, as with fertilizing, you do not want to stimulate new growth.

Photos by John Riley.

Sally Holmes

Golden Celebration Hey John, “What else should I be doing in August?”

Your other late summer jobs in the rose garden include: • Plant container roses that you have been maturing on your patio. You can plant now, but be sure to keep watering. If you plant later than August in our area, there may not be enough time for the roots to establish before winter. Without good roots, the rose may not be able to maintain moisture levels and come out of dormancy in the spring. • Apply insect controls if needed. Our typical bugs along with the Japanese beetles are rose midge, spider mites, or thrips. • Continue treating for diseases.

Black spot is most active between 65 F and 85 F. Therefore, during the hot days of summer you can cut back on your spraying schedule. • Water, water, water.

For more information on any of these topics, go to the Kansas City Rose Society webpage https:// www.kansascityrosesociety.org/ growing-roses.html. And, don’t forget to visit the Rose Library www.kcrsroselibrary.com.

The Ask-a-Rosarian hotline is always available for your specific rose questions by sending a detailed email to kcrosehelp@gmail. com. One of the Kansas City Rose Society Consulting Rosarians will reply with an answer, usually by the next day.

JOHN RILEY Consulting Rosarian

John Riley is an American Rose Society Consulting Rosarian and is Secretary of the Kansas City Rose Society. He is a past president of the Johnson County Rose Society and is on the American Rose Society Board of Directors representing the Central District. John is a retired mechanical engineer who is an opera fan and goes to a lot of soccer games.