Gardening Note #10

Roses


Roses require very high maintenance but will grow well in Cumberland County if: 1) planted properly in well-drained soil, away from tree roots, and 2) a regular spray program is followed. They generally bloom from early May until late fall.

How to buy:
Buy from reputable nurseries only. Bargain roses are very often plants that are not named correctly and have been discarded by greenhouse growers. They usually have an understock that is suitable for greenhouse growing but is unsatisfactory for garden use.

Types:

Cultural Needs:

  1. Sun: need at least 6 hours per day of sun; morning sun is particularly valuable as foliage dries sooner, preventing mildew and our most damaging disease, black spot.
  2. Water: At least 1 to 1-1/4" per week. Water at soil line; wetting foliage encourages black spot fungal disease as well as powdery mildew.
  3. Mulch: 2-3" of pine straw or pine bark mulch, replaced each spring, discourages weeds and helps retain moisture.
  4. Soil: Roses do well in our clay soils since they are rich in minerals and retain moisture BUT only if the soil is amended with compost or other organic material so that soil is loose and well aerated. If manure or compost is not available,a commercial manure product such as Black Cow or a similar product may be used along with pine bark mulch, mixed well into the soil.

Planting:

Fertilization

Established Plants:

New Plants: Do not fertilize in spring until buds are forming.

Type and amount: Use 1/2 cup per plant of 8-8-8 or 10-10-10, put in a circle about 6" from the stem; scratch the soil lightly and water it in well.

Insect and Disease Control Spray Program:

  1. Begin spray program about April when leaves are almost fully out (start sooner in an early spring). Continue spraying at 7-10 day intervals through the end of October. Be sure to spray both sides of the leaves. Do not spray when the temperature is above 85 degrees.

  2. Formula:
    1 gallon of water
    4 teaspoons Captan
    1/2 tablespoon benomyl (Benlate)
    1 tablespoon acephate (Orthene)*
    10 drops Spreader Sticker (helps spray adhere to leaves)
    * 4 teaspoons of liquid Sevin may be substituted for acephate but ONLY during prevalence of Japanese beetles

  3. In January or early February, after plants were cut back in December and have gone into dormancy, apply a dormant spray: Use liquid lime sulphur according to label directions, covering the bed AND bushes thoroughly. If red spider mites, black spot or mildew have been serious problems during the previous year, this dormant spray may be repeated after 2 weeks. Do not use this spray after sprouts have formed.

  4. Sanitation is an important part of disease control. Rake up and destroy any diseased leaves that have fallen to the ground, since they contain the innoculum for next year's disease. In early spring, remove old mulch and replace with fresh mulch.

Pruning:

Cutting:

When roses begin to bloom, cut short stems, leaving 2-5 leaflet sets on stem. As the season progresses, longer stems may be cut.

Gardening Notes Index Page Return to Master Gardener Page
This information compiled by Cumberland County Master Gardeners.
This page was created on 4/20/98 using the Durham Master Gardener Homepage as a model. Our thanks to them and especially to Pauline Marx, Pam Reading and Eileen Lowenbach.
Revised on 05/07/98.