Growing gorgeous roses is well worth the effort.
While some people are intimidated by roses, others are driven to the challenge of having the awe inspiring rose bed. Roses do well in Colorado. Jensen's Flower and Garden offers a wide selection of what we believe to be the best roses available by Jackson & Perkins and Weeks. With over 30 varieties to choose from we know you will find the perfect rose for your garden.
Building a rose garden consists of a few simple steps. The first step is the site selection. The site should be level and have at least 4 to 6 hours of sun each day. Roses should be placed where there are no competing tree roots and provide access to beds for care without compacting the soil.
Roses prefer rich, loamy soil. Roses cannot stand in water, so adequate drainage is required. To test the drainage in a specific are a percolation test can be done. Dig a hole, 18" deep and 8" wide, fill with water. Based on the time it takes to drain, you can determine if the site is ideal and/or how much soil amendment will be need. If the water drains within 30 minutes the site is ideal. If it takes 2-3 hours, soil amendments will need to be added or a different site should be selected. If the water takes 4 or more hours the site is a poor choice. To amend the soil, add organic compost and outdoor planting mix. Good soil equals good roses. Rich, organic soil has uncountable numbers of soil organisms. Very good soil is composed of up to 50% air and water. Good rose soil is never compacted, that is why it is important to access the beds from outside, or use stepping stones.
Now that you have the site ready, it is time to plant your rose bush. Plant after the last frost, May 15th is the average last frost date in our area. Keeping the root ball intact plant the graft 2-4 inches below ground level. This protects the graft during the Colorado winters. For the first 3 days water every day and every 2 days for the next 2 weeks.
Mulch is a critical step that needs to done. Mulching is very useful for growing healthy roses. A 2 to 3-inch layer of compost, bark chips, straw, or similar material discourage weeds, aids water retention and helps keep the roots cool during hot weather. Since some mulching material will take nitrogen from the soil, replenish it with a high-nitrogen fertilizer.
Watering is dependent on weather, drainage and soil structure. A mature, full size rose on average needs 1 inch of water a week. Always water at the base, or in the morning.
It is important to replace the nutrients your rose takes from the soil through the growing season. As soon as your roses are in full leaf, apply a balanced fertilizer, such as Bill's Rose or Fertilome Rose Food, inside the drip line, in a circle a foot or two from the base. Always apply fertilizers according to the instructions on the product label. The checklist below shows a schedule that you can adjust according to your needs.
1. Fertilize when plants are in full leaf.
2. Fertilize again after first bloom.
3. Fertilize 6 weeks before anticipated first frost, but not after September 1st
4. For proper hardening of plants for winter, do not fertilize late in the fall
There are a few maintenance activities that should are associated with growing healthy, beautiful roses. Insects and fungus, pruning and winterizing are three tasks that will improve your rose bushes.
Your roses are planted, watered and fertilized and all of a sudden you notice circles or ovals cut out of the leaves and black spot what should you do. These are two examples of pests and fungus that attack roses. Below are a few common pests and fungus in our area and a sample of how they can be treated.
Aphids - Very small insects, usually green or black, mostly on the underside of leaves and on new growth. Deformed, stunted new growth & blooms. Weakened plant, curling leaves, sticky honeydew on foliage. Presence of ants Thoroughly hose aphids off foliage; you can also apply insecticidal soaps, Neem oil or Imidacloprid (systemic) to control aphids; introduce beneficial insects such as ladybugs.
Leaf Cutter Bees - Circles or ovals neatly cut out of the leaves, wilted stems indicate tunnels inside Seal canes with white glue after pruning to prevent the insects from tunneling the stem .
Spider Mites - Leaves turn yellow, dry out, and in severe cases, fall of the plant. Tiny webs on underside of leaves. Leaf appears speckled, or flecked. Webs may appear on underside of leaf. Lower leaves infested first. Hose the undersides of leaves with a fine spray of water for 3 days in a row to disrupt breeding cycle. Miticide sprays.
Black spot - Leaves have black spots, and will fall off if fungus is not treated Pick off isolated leaves; control with a fungicide spray. Provide good air circulation; water when foliage will be dry before dusk.
Canker Dieback - Rose canes turn dark brown and black and die progressively down the stem Always remove damaged part of the cane, then follow a regular spray or dust program. Avoid injury to the canes, and use a sealer after pruning.
Powdery Mildew - Leaves are distorted and covered with fine white fungus growth Control with a fungus spray that controls powdery mildew disease. Provide good air circulation.
Yellow Leaves - Leaves turn yellow and may fall off. Could be caused by poor drainage Bad weather can slow chlorophyll production, so wait it out. Add sand or gypsum to improve drainage.
Pruning improves the plant health and encourages new growth and bloom. Pruning also controls the shape and size of the rose bush. Do not be afraid to prune your roses. To prune your roses you will need a sharp pair of by-pass pruners, long-sleeve shirt and good gloves. Pruning should be done for the first time around the last frost date. At the same time, remove the winter protection and fertilize. Remove all dead, diseased and damaged canes when pruning. Open up the center to improve sunlight and air movement. Cut along canes to healthy new growth above outward-facing bud eye. It is okay to cut to ground if needed. Always cut at a 45-degree angle, ¼ inch above outward facing bud. Cut too low may injure or kill new bud growth. Slant the cut away from the bud. Cut back to good growth - pith should be white and clear.
Dead-heading is the removal of rose blooms that will encourage re-bloom. Prune down to highest five-leaflet leaf. Stop dead-heading in late September. During summer months, remove weak growth as it occurs.
The final step in growing gorgeous roses is proper protection during the winter, especially in Colorado. Let the last blooms of the season stay on the plant to form hips. This will slow down the growth and help your plant go dormant. Apply last fertilization by mid-August. Reduce watering in September. Rake off and remove all leaves from the rose bed to prevent disease. In order to protect roses during the winter, pile or hill a loose and well drained soil/compost mix to a depth of 10-12". Material must be well-drained, wet and cold is more damaging than dry and cold. Continue to water your roses regularly in the winter; especially in Colorado where the moisture content in our snow is very low.
Now that the rose bushes are planted, fertilized and watered, sit back and enjoy your beautiful roses.
We hope to see you soon at Jensen's Flower and Garden to see our roses that are in full bloom. We will be happy to help you with any of your questions and all of your gardening needs.