June in a Connecticut Rose Garden
by David Candler
June is the month of the first flush of rose bloom- the results of the efforts put forth to date. If the plants of last summer were well maintained, if the roots of those plants were healthy and a full stockpile of energy for the following spring, if the winter protection was adequate to protect the roots and bud union (crown), if the spring was warm and yet provided plenty of rain, and if your efforts to remove the winter protection in about April, and feed the roses in early May were completed appropriately (with some pest controls starting in April for disease and May for caterpillars and aphids) then you have healthy bushes, ready to reward you many times over this month.
The attention needed in June to fully allow the rose plants to bloom with maximum glory are these:
Planting- you should have completed your bare root additions by now. But many plant /garden stores have been potting and growing roses for you in their greenhouses for the last two months. This is a good time to purchase local, fully leafed out, potted rose bushes. After they are in the ground they can be treated like they had been there all along.
Water- continue to ensure that the bushes receive 1 inch of water from nature or hose. This is 3 gallons per plant. In May this is sometimes available from nature. For the remainder of the summer, rain is more and more unlikely to suffice. See other articles here on my web www.ctrose.club concerning ways to may the watering burden easier, especially if you maintain a garden of more than 20 roses.
Food- continue to feed your hungry bushes. Fertilizer may be applied to new, fully leafed out plants. An easy method of applying sufficient nutrients to your bushes is to apply the equivalent of 1 cup of 10-10-10 to each mature hybrid tea of floribunda. Smaller plants and miniature roses get proportionately less- about ½ cup. Climbers, or really big plants, should receive up to two cups. If you can afford the time to apply the fertilizer twice as often, then use half as much at a time, of course. If you use fertilizer with proportionately more Nitrogen, then use proportionately less at a time (e.g. for 20-20-20 use ½ cup instead of a cup). Don’t obsess on the K and P value in N-K-P fertilizers, the N is more important. If you take periodic soil samples (every year or so) you may be more selective in fertilizer choices, but that is a refinement. Exception: the K portion of fertilizer is particularly important for flowering. You might consider something like a 10-30-10 blend for June’s application.
Pest Control- continue a consistent preventive spray program for fungal disease. For readily-available chemical sprays (e.g. Ortho Rose and Shrub Disease Control [was Funginex]) this generally means spraying every 7-10 days. Be alert to any developing issues, and research appropriate responses. The biggest concern in CT is usually Black Spot disease. Briefly, this shows black spots on the leaves followed by yellowing and drop-off of the leaf. Any of these visual symptoms are “too late” signals for those leaves. That’s why you must be preventive in disease approach. Black Spot requires hot days, and thrives on plants whose leaves do not thoroughly dry. So you’ll see it June-Oct. Other fungal diseases in CT are Powdery Mildew (white powdery appearance on leaves), anthracnose (looks similar to Black Spot), and Downey Mildew (much more rare). Rust, so prevalent in western US, is not a threat in CT. A note for small gardeners, particularly: mix up only the chemicals needed for the weekly spraying. Mixed solution does not retain its effectiveness- you cannot store the mixed version properly. For all: which diseases, what to use in defense, etc. are great topics for both more reading and contacting a locally-based Consulting Rosarian (list available on this website).
In addition to disease, the other common pests on roses are insects and mites. For the caterpillar form of insects and for Japanese beetles, you may need stronger doses of spray insect control. One commonly available product is Orthene. This also requires 7-10 day application. Read the labels of all chemicals!! The appropriate ‘dose’ or strength is different for aphids (May, June) than it is for caterpillars (later May-July) and Japanese beetles (July-Aug). Use these when you see the problem. Caterpillars are almost always near where holes in the leaves are found. The search-and-pluck method works very well.
The method of pest control to use is heavily dependant on your needs and level of tolerance for both critters and chemical defense. See other articles on this website on the topic of Integrated Pest Management (IPM) for much more information on that subject.
Disbudding and Deadheading- Disbudding: picking off side buds on a stem (early) will produce a larger single bloom (on HT, and many miniatures). Picking off the center predominant bud (early), will usually produce a stem of larger, similar-sized flowers blooming together (for floribundas, shrubs, many minis). These are nice for the average gardener, but more important to the exhibitor in rose shows.
Picking off spent blooms (Deadheading) encourages more blooms to develop faster and provides for a more pleasant garden. Deadhead to the extent that is fun and for which your time schedule allows. This is more icing than cake.
Enjoy the blooms in the garden or cut them and bring them in the house. And if you have sufficient flowers, give some to others. June is the biggest harvest month, but you’ll see blooms throughout the summer for most modern varieties of roses. Enjoy!!!