Centuries after their introduction, roses remain a garden staple for their lush, fragrant, delicate flowers. Growing roses requires interest and some commitment to specialized care.
The following list highlights common rose types and their attributes.
The number one consideration in planting roses is light. At least six hours of direct sunlight is necessary. Not only will this encourage maximum bloom, it will help moisture evaporate more quickly, thereby warding off problems associated with dampness and humidity. To further reduce problems with foliar diseases, plant roses where air circulates freely, but not in the path of regular, strong winds. Spacing roses four to five feet apart will also aid air circulation. Avoid planting where roots of trees or shrubs will steal water and nutrients intended for roses.
During the growing season, roses need regular, deep watering, such that water penetrates the soil about 18 inches deep. Well-established plants need five to ten gallons of water every four to six days in summer, and new plants need three gallons of water every three days or so. Building a basin around roses at planting provides a simple way to water. Basin irrigation with bubblers minimizes the amount of moisture held on foliage, reducing the incidence of: 1) Black Spot and 2) Rust. Overhead sprinklers, on the other hand, neutralize: 3) Powdery Mildew spores and provide partial control for 4) Aphids and 5) Spider Mites. They also remove spray residues, leave mineral deposits on foliage and encourage black spot and rust by keeping foliage and atmosphere damp. If you sprinkle, do it early in the day to be sure foliage dries by nightfall. If you irrigate in basins, spray plants with water occasionally.
Roses prefer slightly acidic soils, best achieved by using acidic soil amendments at planting and mulching yearly with acidic materials. To plant, dig a hole about two feet wide and deep and incorporate one-third Gardner & Bloome® Rose Planting Mix or Master Nursery® Gold Rush or Bumper Crop with your native soil. Add Master Nursery® Master Start to this soil, then create a cone shaped mound at the bottom of the hole and drape the rootball over it, keeping the graft union or crown of the rose at least one to two inches above ground soil level then backfill with the soil mix. Build basin at this time and water in well. To mulch, use Master Nursery® Forest Blend, Gold Rush, or mini-mulch and spread about two to three inches thick. Mulching helps conserve water, prevents soil surface baking, keeps soil cool in summer, deters weed growth, makes the area more attractive, and provides minerals and organic matter as it decomposes.
Use Master Nursery® Rose & Flower Food or Gardner & Bloome® Rose and Flower Fertilizer monthly: from February to September, to supply nutrients for developing roots and stems. You can substitute Concern® All Natural Weed Prevention Plus® (a corn gluten product) for the February application to give your roses a slow nitrogen boost and prevent annual weeds in rose beds. You should apply Alfalfa Meal in March and June to stimulate cane development. If you use organic fertilizers supplement them with Iron Sulfate if any symptoms of chlorosis appear.
The three most common fungal diseases of roses are powdery mildew, rust and black spot. Always check with your nursery professional to properly diagnose problems before undertaking growing season sprays. All three can be controlled with: Monterey Liqui-Cop®, Safer® Garden Fungicide, sulfur powder or Master Nursery® Pest Fighter® Year-Round® Spray Oil. These fungicides are preventives and prevent spreading, but will not cure diseased leaves and must be applied before the plant is infected. Each is considered organic. Bonide® Fung-onil™ (Chlorothalonil) is a curative fungicide and will prevent and cure the three listed diseases.
The most common insect pest of roses is the Aphid, (shown above) which can be controlled with Master Nursery® Pest-Fighter® Year-Round® Spray Oil, Malathion, Monterey Take Down Garden Spray or
Safer® Insect Killing Soap. Caution: Do not use sulfur or oil products within four weeks of each other during the summer. Other insect pests include: Katydids and Cucumber Beetles and Rose Slugs, all of which can be controlled with Malathion, Monterey Take Down Garden Spray, Sevin (Carbaryl) or Safer® Insect Killing Soap. A totally organic spray which works on all chewing insects, but not sucking insects, (aphids, scale, mealy bugs, etc.) is Spinosad. (Please review our Spinosad Care Guide.). Mild to heavy mildew infections can be eradicated by spraying with horticultural oil. When horticultural oil is used as an insecticide, it must contact the insects. It has no residual effect. The same is true for insecticidal soap.
Different types of roses require specific dormant pruning care, usually undertaken in January in our area. In January, attend our free, annual Rose Care & Pruning Seminar; check our website for the date. The seminar features hands-on learning. During growth, deadheading, the process of removing spent blooms will encourage continuous bloom in most roses. Find a leaf that faces to the outside of the plant and cut at about a 45° angle just above the node. Since the new flower stalk will develop at that juncture, make sure the cane is sturdy. If it is not, choose a point lower on the cane at which to cut.
Each year after dormant pruning roses, they should be treated with a dormant spray mixture. Our recommendation is two tablespoons of Monterey Liqui-Cop® plus six tablespoons of Master Nursery® Pest Fighter Year-Round Spray Oil in one gallon of water. Spray the pruned roses until dripping. The Monterey Liqui-Cop® treats disease microbes and the spray oil kills dormant insects and overwintering eggs. Both are accepted organic.
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