Black Spot

Black spot only affects roses. It is caused by the fungus Diplocarpon rosae. Black spot is the most common disease for roses. Symptoms include round velvety lesions often surrounded by a yellow halo. These lesions form a cluster and result in patches of black spots. If left untreated, the leaves will turn yellow and fall off the plant prematurely.

There are many schools of thought in disease prevention and control. Some people want to go organic and others like to use powders and chemicals. We will provide a method for both forms of disease control and prevention.

In the use of organics, prevention is the key to disease control. One of the best ways to begin is to help build the plants immunity. In early spring, as the plant begins to show signs of coming out of dormancy, add a good amount of compost tea to the soil and root system. This will stimulate the growth of beneficial micro-organisms. The stimulating of microbial activity will weaken the ability of pathogens to take control of your plant. This will also help build healthier and nutrient rich soil. Continue using the compost tea once a week or bi-weekly as needed. There are many forms of organics available today. Worm juice is a liquid run off of a worm bed. It produces much of the same results as compost tea. Worm castings and old fashion compost also strengthen the soil, just in a much slower manner. Take the time to research and figure out the best method for you and your plants.

There are many chemicals and powders, or dusts, available on the market today. Your local hardware store or nursery will be able to provide these for you. I would recommend asking at your local nursery, what is the most effective method for your climate and soil type. Theses factor change based on the regions we live in. June is typically the time of year black spot begins to show up. You will want to begin dusting your rose bush as soon as you detect black spots and continue once a week through the warm humid months.

No matter which process of prevention and treatment you choose, paying attention to your plant will allow you to produce a better plant. Always remove dead and fallen leaves and braches from the area of the rose bushes. Burn or throw away all dead or yellow leaves. If they remain at the base of the plant, they have the opportunity to re-infect the plant.

Pruning rose bushes

Pruning rose bushes is important to encourage new growth and help develop large full healthy rose bushes. In the winter months you will want most of the nutrients to go to support the stalk and root system. Cut and remove any branches that cross through the center of the plant. Cut and remove 1/3 of the length of each branch. This will remove a large portion of the leaves and branches. This will leave the branches larger and stronger each year. The best time to cut back a rose bush is just after the first frost.