University of Illinois Extension

 

Sharon Yiesla
Unit Educator, Horticulture
Lake Unit

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The Roses Are Coming

Now that spring is here, the roses will soon be arriving at a garden center near you. There are many types of roses available (see table below) and with so many to choose from, it seems an almost impossible task to make a selection. Before you decide to purchase a rose, consider what characteristics you want and make a shopping list. Consider cold hardiness first, since not all roses can make it through a northern Illinois winter. Next look at disease resistance. Roses are prone to some common diseases like black spot and powdery mildew. Roses that are resistant to these diseases will be better looking and will require less maintenance (less chemical use). Other things to consider include the size and form of the rose plant, blooming habit (does in bloom once or does it rebloom), bloom color and fragrance (not all roses have fragrance). Once you have your list together, you can look for roses that fit the characteristics you chose.

There are some ways to insure that you select quality roses. Look for roses with a rating from the American Rose Society (ARS). 10 is perfect, 9-9.9 is outstanding, 8-8.9 is excellent, 7-7.9 is good, 6-6.9 is fair and 5.9 and below is of questionable value. The “Handbook for Selecting Roses,” a list of roses and their ratings is published by the American Rose Society.

Another group that tests roses is All-America Rose Selections (AARS), a non-profit group. Only a few roses are designated as All-America Rose Selection winners. The AARS designation indicates a quality rose that has been tested in a variety of growing conditions.

Once you have decided on a rose, you need to look for a good specimen of that variety. The American Association of Nurserymen has established a system of grading roses that are budded (grafted) onto a rootstock. The grades are 1, 1 1/2 , and 2, with grade 1 being the best. Buying grade 1 is highly recommended as these plants will grow better and produce more roses in the first season that roses of lower grades. Even when buying grade 1 roses, it is good to carefully examine the plant. A high grade rose that has been mishandled may not grow well. Roses growing on their own roots are not graded.

Roses may be purchased either bare-root (those that are packaged in plastic bags or cardboard boxes) or in containers. When buying a bare-root plant, look for canes that are plump, green and firm. The root system should be fresh looking and in balance with the top part of the plant. Avoid bare-root plants that have started sprouting in the store as that growth may be weak and the plant stressed.

When buying container grown roses, again look for plump, green canes. Avoid plants that appear to be too big for the container in which they are growing; they may have been in the container too long. Look at the bottom of the container. If roots are protruding from the drainage holes, the plant may be potbound and may not grow well when transplanted. Do not buy container plants if the soil in the container is dry. This stresses the plant.

Class Hardy to Northern Illinois? Flower type Frequency of Bloom Fragrant Flowers Height Disease
Species Roses Some species are, some are not Mostly singles Once a season (most) Varies by species Varies by species Most are disease resistant
Gallica Most are Single, semidouble, or double Once a season Yes 3-5 feet Most are disease resistant
Damask Some are Semidouble or double Once a season (most) Yes, very fragrant 5-6 feet Most are disease resistant
Alba Most are Single or double Once a season Yes 5-8 feet Somewhat resistant (rust and blackspot can be a problem)
Centifolia Some are Very double Once a season Yes, very fragrant 4-6 feet Susceptible to disease
Moss Rose Some are Double or very double Once a season (most) Yes, very fragrant Variable Susceptible to disease
Bourbon Hardiness varies Semidouble, double, very double Repeat bloomer Yes 5-6 feet Somewhat resistant (Black spot is serious) Hybrid Perpetual
Hybrid Perpetual Hardiness varies Double or very double Some will repeat Yes up to 7 feet Susceptible to disease
Hybrid Tea Hardiness varies Semidouble or double (some single) Repeat bloomer Fragrance varies from slight to intense 2-6 feet Susceptible to disease
Polyantha Hardiness varies Double Repeat bloomer Very little fragrance 1-4 feet Most are disease resistant
Floribunda Hardiness varies Single or double Repeat bloomer Little to no fragrance 1 2-4 feet Susceptible to disease
Grandiflora Hardiness varies Semidouble or double Repeat bloomer Lightly fragrant 3-6 feet Some varieties have good resistance, other don't

 

April-May 2003: Planting Trees | Prevent Garlic Mustard from Setting Seed | The Roses Are Coming | Unusual Vegetables

 

Past Issues

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