U of I Extension garden article

Summer care of roses

By Jennifer Fishburn, horticulture educator,
University of Illinois Extension, Logan-Menard-Sangamon Unit

[June 06, 2013]  On my way in to work each morning, I have the pleasure of being greeted by the heavenly scent of Mr. Lincoln hybrid tea roses and Knock Out roses.

I think every garden should contain at least one rosebush. There are few plants that compare to the beauty and scent of roses. Careful consideration should be given to the type of rose selected for a garden.

When selecting roses, be sure to note the resistance to diseases. Roses are susceptible to a number of disease and insect pests. While roses may survive without a pest control program, they may not be very attractive. Healthy roses are better able to withstand diseases. Encourage healthy plants with proper site selection, good soil preparation, good drainage, proper spacing, disease-resistant cultivar selection, proper plant maintenance and adequate moisture.

Ideal growing conditions for roses include full sunlight, good air circulation and well-drained soil high in organic matter. All-day sun, at least six hours, is preferred. Morning and mid-afternoon sun are preferred to late-afternoon sun. Morning sun helps to dry the leaves quicker, reducing the potential for disease.

Roses prefer uniform soil moisture throughout the growing season. The rule of thumb is 1 inch of water per week. A soaker hose is the preferred method for watering roses. Soaker hoses apply water to the soil while keeping the foliage dry.

A 2- to 3-inch layer of organic mulch will help retain soil moisture, keep soil cool and retard weed growth. Materials such as shredded hardwood, straw or herbicide-free dry grass clippings make good mulches.

An annual fertility program is a must to maintain strong, healthy roses. Fertilization schedules vary depending on the type of roses being grown. Begin with a spring application of general purpose fertilizer such as 10-10-10 or 12-12-12. Use about one-half to 1 cup of fertilizer per plant. Spread fertilizer in a band starting 6 inches from the crown of the plant and going out to about 18 inches. Lightly work fertilizer into the soil and water.

Most roses will benefit from a second application of fertilizer around June 15 or at the end of the spring bloom period. For continuous-flowering or repeat-blooming roses, a third application in mid-July is suggested.

Another fertilizer option is timed or controlled-release fertilizer. These fertilizers release nutrients slowly over the season. Apply time-released fertilizers in May.

The pruning of rose bushes is another important maintenance consideration. Pruning can often be confusing for many gardeners. The class of rose and the time of year it blooms influence the type and amount of pruning. The majority of pruning is done in the spring. When pruning, use clean, sharp pruners and cut at a 45-degree angle about one-fourth inch above an outward-facing bud. The cut should slant away from the bud. After making a cut, it is suggested to seal the ends of the cuts with white glue to prevent the entry of cane borers.

For recurrent-blooming types of roses, it is important to deadhead plants. Deadheading is the removal of faded flowers. The rule of thumb for vigorous growing plants is to cut the flower stem back to an outward-facing bud above a five-leaflet leaf.

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Information for this article was obtained from Our Rose Garden, a University of Illinois Extension website that contains information about selecting and growing roses in Illinois.

[By JENNIFER FISHBURN, horticulture educator, University of Illinois Extension, Logan-Menard-Sangamon Unit]