If you cringe with distaste at the thought of hosing down your roses with chemical pesticides, then maybe this is your time to "go green" in your rose garden. While many gardeners fear that organic pest and disease control for roses will leave a window wide open for rose enemies to attack, the reality is that your plants will be "happier" and healthier without so many chemicals in their systems, not to mention that the groundwater and the overall environment will be better off.
Some people consider organic pest and disease control to be the planned and coordinated avoidance of chemical pesticides. However, some take it a step further, saying that all fertilizers should also be entirely natural, ruling out limes, sulfurs and coppers. For the purposes of this article, we will assume that any chemical or chemically altered material is not organic.
Organic pest and disease control for roses has two facets: driving things away and using natural methods of control. Basically, if you cannot deter the insect or disease invasion, then you will need to find something to eat or otherwise eliminate that disease or insect naturally. This means that organic methods can use natural elements to kill off an insect invasion if necessary even though the user would likely not endorse the insect eradication were it conducted via chemical means.
Finding Good Fungi and Friends
If the soil in your garden is full of good fungi and organisms like nematodes and bacteria, then the "bad" ones will be less likely to take hold and invade your roses. Use organic fertilizers that are high in natural phosphates, nitrates and sulfates to keep not only your plants strong, but also the organisms in the soil around them. Nematodes can also be installed in your garden to eat Japanese beetles while they are still in the larval stage.
There will be times that you simply need to kill off some bugs, particularly if aphids, mealybugs or scale insects have infested your roses. Coat both the tops and the bottoms of the leaves of the plant with neem oil. It will smother the bugs, and is a natural, horticultural oil. Ladybugs can also work as a "natural insecticide" since they eat several different pest populations. However, they will not stay in your rose garden if the pest population is gone, so they are not particularly practical in small, confined areas.
The best form of organic pest and disease control for roses is prevention. Use sterile pruning to remove infected foliage and flowers as soon as you spot them to reduce the risk of a widespread disease problem in your garden. Rake out the area underneath the bushes regularly to prevent an environment that cultivates fungi. Apply a thick layer of mulch early in the growing season to help fortify your rose bushes against disease so that they can fight off infections on their own, and when you water your roses, use a drip hose and do so early in the morning.