August in a Connecticut Rose Garden
Steve Rogers

August is a transition month for Connecticut rosarians.  We need to continue the horticultural practices of watering and pest management that we used throughout July, but we will begin to alter our fertilizing and pruning practices with an eye towards the end of the growing season for roses … unfortunately.  On the positive side, however, the month of August will produce the second peak bloom on those bushes that repeat.  Well cared for plants will yield some very nice specimens for bouquets or single stem centerpieces for our dinner tables or to give to friends and family.

After August ends, we will not apply any more granular fertilizer for the rest of the growing season, because we do not want to over stimulate the plants at this time of year.  We may, however, continue to foliar feed with a liquid fertilizer according to the product’s directions.  This will spot feed the plants through this stressful month with no long-term stimulative effect.  (Editors note: the over-stimulating refers creating additional stem and leaf growth through Nitrogen in fertilizer, since that new/tender foliage will dieback in the winter.  Recent past winters (03, 04) have caused dieback nearly to the ground for many rose plants, other than some shrubs.  The condition of the roots is the key factor in survival and replacement canes next spring.  Providing sufficient nutrients to build even stronger roots is important: these are Phosphorus and Potassium (Potash), the "P" and "K" portions of the fertilizer's N-P-K credentials.  Ensure these two constituents are available, even while decreasing the Nitrogen contribution, and perhaps the roots will be stronger next year for the regrowth process). Continue to water at the rate of at least 1” (3 gal per bush) a week and more, if needed.  Our goal is to keep the plants as healthy as possible during this month when Mother Nature can be less than helpful.  Ensuring the right amount of water is probably the most important thing we can do for our plants since August in CT is nearly always dry.

Thankfully, the Japanese Beetle “invasion” will come to an end in early (or mid) August, and this is a good time to apply a grub control product to our lawns to keep next year's Beetle population to a minimum by breaking their life cycle.  Our pest management program must continue to focus on fungus prevention.  Along with black spot prevention, conditions will be just right (warm days -above 80 degrees, and cool/damp nights) for powdery mildew.  Keeping as close as possible to a weekly preventative spray program during this period of time should keep these two problems to a minimum.  The best time to spray well-watered plants is in the cool early morning, long before the heat of the day.

Finally, as we cut the flowers during the month we will keep in mind that this is important pruning.  The health of the plant, and planning for a third flush of bloom in the fall should be considered when we cut flowers for bouquets or to just dead head our plants.  “Fishing Rod” type growth (long shoots) will appear from our OGRs, and should be pruned back/below to the desired over-all plant height.  It is important to do this to keep the plants “under control”, and for the overall health of these plants.  Shrub roses can be kept in check with proper/aggressive pruning as well during the month of August.  The desired shape and size of our plants should always be in our thoughts when we are “cutting/pruning” our plants.

Although the colors of our blooms may not be as brilliant in August as we might otherwise expect, because of the effect of the long sunny days, we know that you will enjoy the second round of blooms in your Connecticut gardens.