May in the Rose Garden time to plant, mulch, water and more

Hey John, I did not get any blooms last year. All I got was new growth that looked like it had been singed by a match?

If your new growth has burntends and the new buds are bent over, I am sorry because you are having rose midge problems. Midges are small fly-type insects. It is OK to spray the rose bush for midge when they are active as it will kill the bugs on the plant at the time. The problem with midge is that some of them may hatch every day, and they attack the new growth which may not have product on it. The way to kill them all is to get them when they are in the soil pupating to the adult stage. Apply a granular product to the soil, according to the instructions, with the active ingredient imidacloprid and if possible, also beta-cyfluthrin. You should use the application rate for insects like lawn grubs. One year that rate was not enough in my garden, and I had to use the higher rate indicated to treat carpenter ants. Try to get ahead of them for the season, apply your granules when you uncover your roses in the spring or shortly thereafter.

Hey John, I see people trying to fertilize their roses by spraying the leaves. Isn’t that what the roots are for?

Contrary to what you may think, many plants are more efficient taking in nutrients through their leaves than through the roots. Up to 95 percent of material applied to the leaves may be used by the plant compared to only 10 percent applied to the soil. One university study of roses found the foliar feeding of N-P-K along with micronutrients significantly increased the size of the plant and the number and quality of the blooms. While foliar feeding has shown to be possible and effective, the mechanism and details are not well understood. For example, how does the use of surfactants affect the results and what is the applicable chemical form of the nutrients? I have no clear advice on how to do it, because there is not enough research to provide guidance. I visited the home garden of one nationally known hybridizer who uses a tablespoon per gallon of water-soluble fertilizer mixed in with his regular fungicide and pesticide spray every week or two. His roses were spectacular. I suggest you join me this season, experiment a little, and let me know your results. Of course, you will also need to follow other good rose growing practices like adequate water and sunlight, plenty of mulch, and regular soil fertilization.

Reference: Gary A Ritchie, PhD, “Some Thoughts on Foliar Fertilization or Roses,” American Rose, Nov/Dec 2022, pp 120-125.

Hey John, What should I be doing for my roses in May?

Spring is a busy time in the rose garden. Your jobs include:

JOHN RILEY Consulting Rosarian

• Planting container roses

• Fertilizing

• Summer mulch

• Spraying for blackspot control

• Disbud for larger flowers

• Water 1 inch per week

Hey John, What should I be doing to get ready for the photography competition at the KCRS Rose Show on June 3?

You should attend Kansas City Rose Society’s Photography Workshop: “How to Photograph a Prize-Winning Rose for the KCRS Rose Show Photo Competition.” This workshop will teach you how to choose the perfect rose, and how to compose and photograph for an award-winning image. Meet in the Garden Center at Loose Park to discuss the photo contest rules and view several award-winning photos from previous competitions, after which you may head out to the rose garden to learn how to choose your perfect rose. Time will be given for everyone to take several photos. Then you will return to the Garden Center to critique your images and answer questions. The Workshop is Saturday, May 13, 2023, from 9:30 a.m. until 11:30 a.m., cost is $5.00, reserve your place online at kansascityrosesociety.org.

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

For more information on these “Rose Report” topics and the Workshop, go to the Kansas City Rose Society webpage kansascityrosesociety.org.