Timely Tips- May

May in a Connecticut Rose Garden

In late April, early May we will make a final assessment of the winter die back, and complete the final pruning steps on the more tender rose varieties, i.e., hybrid teas, floribundas, grandifloras, and miniatures. Our hardy shrub roses have been pruned, and have come through the winter in very good shape. This winter was warmer than most, and the spring is unprecedented for warm! There was perhaps 55% die back, and the initial rough pruning removed a significant amount of dead (black) wood from these plants (down to 12 inches on HT's in much of the state, or down to the level of fully effective winter protection (soil mounding, or similar). Allow ample time for bud breaks to occur on the remaining wood, which will help determine where the viable wood is before doing any further pruning on these plants.

Also, at the beginning of May we will commence our granular feeding program with the application of a 10-6-4 (or 10-10-10 , etc.) garden fertilizer. Each large bush will get a cup spread around the drip line, while the miniature roses will get a ½ cup each applied in the same manner. Mulch will be pushed aside during this process to allow us to apply the fertilizer directly to the soil, and scratch it in. Although spring usually provides ample rain, be sure to water thoroughly after the application of the fertilizer. Additionally, we will now begin to pay closer attention to the amount of rain we are getting during this month, and supplement with watering as needed to ensure that the plants get at least an inch of water a week (about 3 gal. per plant) during this active growing period.

This month we will start a preventive spraying program of a systemic fungicide according to the directions on the selected product’s label as soon as the foliage is present. This is the only successful way (i.e. preventive) to control/prevent blackspot, which will always appear to some degree on susceptible plants early in the growing season, and if left untreated will lead to plant defoliation by summer time. We will also begin our Integrated Pest Management program (see the many articles and links to IPM on this website, in the Rose Culture section) as spider mites and aphids may appear if conditions are right. Use appropriate sprays very selectively and in a focused way if needed to control any significant outbreak of these pests. We have learned that less (e.g., Orthene) is better, because we want to minimize the removal of the beneficial insects that will prey on the aphids and spider mites. (Ed. Note: fungicide is used preventively, insecticide is best used reactively).

Additional Editor's Note: Midge has been reported by more and more New England rose gardeners in the past several years. There are several articles concerning the Preventive Measures (in May/early June) needed to reduce the damage caused by these very bothersome pests. See the Rose Culture section of this website.
Other considerations:
Evaluate your current roses from past data and from how they look/survived as of mid-May. There is still time to replace poor roses with new potted ones from the Garden Center.
Water your roses if there is an unusual (for spring) dry spell and especially after fertilizing.
Keep your pruners sharp.

This is a suggested timetable that we will follow, and a set of basic rose culture tasks that we will do to care for our roses in the month of May in our garden. If you have a question about rose culture please contact any of the American Rose Society Consulting Rosarians listed elsewhere in this site for the help you need. Call a CR!
Happy rose growing!