Regional Growing Guide: Western Mountains & High Plains
From the eastern slopes of the Cascade and Sierra ranges through the High Plains, this generally arid region battles bitterly cold winters, blustery spring winds, little rain and sometimes brutal summer heat. The soil presents challenges, too, be it alkaline, sandy, clay or infused with salt and boron. Fortunately, the severe climate poses few insect or disease problems. But the roses that thrive here must be cold hardy and survive wild swings in temperature. They often bear strong, leathery leaves to resist desiccation. They also appreciate regular irrigation, heavily amended soil, a thick layer of mulch and protection from the wind.
Select a season: Spring Early Summer Late Summer Fall
Managing Common Rose Diseases
Growing roses in the western mountains and high plains is often a challenge for the newcomer, but with the proper plant choice, site placement, and common-sense care techniques, roses will thrive with vigorous green foliage and an abundance of blooms.
To protect your rose garden from a severe outbreak of some of the most common diseases, follow some sensible growing practices.
Powdery Mildew
The first sign of powdery mildew, one of the most common rose diseases, is a white, powdery substance on the surface of the leaves. Infected leaves turn purplish and curl upwards, and flower buds die without opening. The disease spores are spread by wind and are especially common during hot summer days and cool nights.
To control powdery mildew, space rose bushes far enough apart to allow for good air circulation. Avoid drought stress by watering plants and mulching with shredded cedar.
Black Leaf Spot
If tiny black spots appear on the leaves in early to late summer, followed by fringed margins on the leaves, you are likely to have an infection of black leaf spot disease. Infected leaves eventually turn yellow and fall to the ground.
Remove fallen leaves to reduce the spread of the disease to new leaf growth. Applying water at ground level so the foliage stays as dry as possible will help reduce the outbreak of blackspot.
Rust
A common disease that covers rose leaves with tiny, orange/black spores is appropriately called rust. It causes the foliage to fall off and weakens the plants. As with blackspot, remove the leaves that show symptoms of infection, collect fallen leaves, and dispose of the debris. Do not compost infected leaves because most composting techniques will not heat up enough to kill the disease organisms.
Rose Mosaic
One of the most frustrating diseases is rose mosaic. This problem is often identified by the characteristic bright lime green or yellow patterns on rose leaves. It's caused by a virus and most often attacks weakened or stressed plants. Infected plants are stunted and have reduced flowering. There are no cures for rose mosaic. Replace infected plants with virus-free rose bushes from a reputable grower.
Protect your rose garden from a severe disease outbreak this year by following good growing practices. Avoid overhead watering -- especially at night -- and use drip irrigation or a soaker hose that will soak the soil while avoiding excess moisture on the foliage. Prune your roses on a regular basis to allow for good air circulation, which reduces the incidence of disease contamination. The best preventative is to select disease-resistant varieties when planning your rose garden.
The Case for Climbers
Amazingly exuberant, climbing roses can transform a chain-link fence, arch over an entryway, or turn a simple trellis into a beautiful boundary. There's no time like the present to build a fence or trellis to support a new climber, or to sculpt and secure a climber you already have in your garden.
Lovely Laterals
As you plan for the installation of a new climber (or prune and tie an old one), keep in mind that climbing roses bloom best when the branches rise up 4 feet or so and then arch outward until they become horizontal. This growth pattern helps the plants intercept lots of light, and it stimulates the production of short lateral branches, which bear the biggest bouquets. Fences that allow air to circulate freely are ideal, provided they are sturdy enough to support the plants.
Beyond trellising, most climbing roses require little maintenance. Allow new plants to grow unpruned for two years. After that, prune out only the oldest canes. Many gardeners prune their climbers only every other year, which works well when the plants are happy with their site, soil, and support structure.