The Best Conditions for Roses
- Successful gardeners pick rose species that will be hardy in the gardener's particular climate zone. The U.S. Department of Agriculture has divided North America into 11 climate zones, with 1 having the coldest climate and 11 being the warmest. Roses grow best in more temperate zones, but breeders have created roses that can live in almost all climates. One example of a rose species that tolerates cold weather is the rugosa rose, a tall bush that produces fragrant flowers with a single row of petals around the center.
- Roses need six to eight hours of direct sun each day. A few varieties will tolerate some shade, but most won't bloom without strong light. If you have a choice between morning or afternoon sun for your rose bush's location, choose morning sun. Morning sun is particularly good for roses because it dries the dew that settles on the rose leaves overnight, thus helping to prevent fungal diseases.
- Roses prefer a slightly acidic soil that is rich with nutrients and has good drainage. Some methods to improve the soil for roses include adding peat moss, animal manure or compost. Work the soil to a depth of 15 to 18 inches. To test for drainage, Rose Magazine recommends digging a hole about a foot deep and filling it with water. If the water drains away in 15 minutes, the drainage is suitable for roses. If the hole still holds water, you may have to add more organic material to loosen the soil. If the water drains away faster, you can add heavier material, like clay.
- Roses are heavy feeders. Most fertilizers are labeled with numbers that indicate the amount of nitrogen, phosphorus and potash in the mix. Roses need a steady supply of all elements, with a slightly higher amount of phosphorus. Phosphorus promotes root growth and flower production. Many rose growers also choose to add Epsom salts to the soil at the beginning of the growing season at the rate of about 1/2 cup per plant. The magnesium is believed to promote flower growth and create more blooms.
- Roses need a steady supply of water, but spraying water on the leaves can lead to fungus. Instead, use a soaker hose to direct the water to the roots of the rose bush. Jolene Adams with the American Rose Society recommends watering at the rate of about 5 to 7 gallons per week, but roses growing in hot weather and low humidity may need more water than roses grown in cooler climates. To help hold moisture in the soil between watering, add several inches of organic mulch around the base of the rose bush.