Black Spots on Roses… Why Are They There?

Black Spots on Roses: Roses are ancient blooms commonly grown for their beauty and medicinal value. They’re planted in gardens and homes to transform the environment with their elegant colors and delightful fragrance. If you’re looking for a cheap but highly effective way of increasing your home’s appeal then roses are among the top options to consider.

While growing roses is typically quite easy, it’s not without its challenges. There are several insects and pests that prey on roses for food. There are also diseases that threaten to destroy the plant.

For instance, if you notice black spots forming on the leaves of your roses that’s a sign the flowers are infected and require immediate attention.

What Causes Black Spots on Roses?

Black spots are caused by a fungus known as Diplocarpon rosae. This is the most serious fungus affecting roses.

The fungus attacks the leaves causing purple or black spots to develop, often in the early stages of the plant’s growth. Other symptoms of the fungus include a yellow color forming around the dark spots of the leaf in which case the leaf often drops. In some instances, small black lesions may also appear on the stem.

The extent of the dark spots is dependent on the severity of the infection. If the infection is extensive the spots will be widespread and the plant can shed almost all of its leaves.

How to Control Black Spots

Black Spots on Roses

1. Prune Diseased Leaves

As soon as you notice dark spots forming on your roses, remove any diseased leaves and destroy them to prevent the infection from spreading throughout the plant and the surrounding flowers. Do not use the leaves as compost in rose beds.

2. Move the Plants

Sometimes the fungus appears when the plant does not receive ideal growing conditions such as good airflow and adequate sunlight. By moving the plants to open spaces where they receive sunlight throughout the day it becomes more difficult for the fungus to form.

3. Replace the Species With a More Tolerant Variety

Choose a highly resistant rose species such as the Rugosa hybrid roses to avoid the black spot disease. You can inquire about other resistant species at your nursery.

4. Keep the Foliage Dry

Fungi need moisture and moderate temperatures to survive. Therefore they will often favor leaves that are consistently wet. If you use overhead watering only do so during the day so the leaves are dry by nightfall.

Contact Tree & Shrub Care Professionals

These professionals know the right fungicides to apply to prevent new leaves from getting infected. They also have expertise in pest control which means they can also help with any insect infestations or pests that pose a threat to your roses.

At EnviroSpray, we are committed to providing high-quality pest control services to ensure you get the utmost protection for your home and garden. Our dependability stems from our vast knowledge and many years of experience dealing with a variety of garden and pest control issues.

To schedule a free consultation please contact us.