Cures for Black Spot

Chemical Control

• Gardeners who know black spot is a problem in their garden should use a fungicide early in the season to try to prevent an outbreak. New growth is most susceptible to attack, but be sure to test the product you select on an inconspicuous area of the plant before applying it to the entire plant. It is important to read the label directions and follow them. Make sure the product you use is suitable for the plant you are using it on and that the product does treat black spot. Sulfur is an option for curing black spot on plants that are infected.

Proper Irrigation Methods

• Proper watering is a great way to prevent and cure black spot. This disease needs moisture to thrive. Always water at ground level, making sure the leaves and stems remain dry. Soaker hoses are ideal for preventing black spot since the water drips onto the ground and does not splash up onto the foliage. Water early in the morning so that the top of the ground or mulch and any foliage that might be wet has a chance to dry before the temperature begins to cool down in the evening.

Adequate Air Circulation

• Proper planting and pruning procedures ensure plants have adequate air circulation. Plants need adequate room to grow and develop. When they are planted too close together, the crowding stunts the plant and is an invitation to pests and disease. Pruning is essential because it allows you to remove diseased stems or canes and open up the plant so air can circulate between the branches. This prevents moisture from building up in the interior areas of the plant, thus eliminating the potential for black spot to develop unnoticed.

Removal of Debris

• Removing fallen leaves, flower petals and contaminated mulch is another way to cure black spot. Discard this material by burning it. Do not compost it. This prevents the spread of black spot and, over time, eliminates the spores from your garden. Continue to remove fallen debris even after the black spot is cured. A good way to deal with bare ground that contains black spot spores is to put 3 inches of mulch on top of the ground to smother them. Make sure the mulch is not right up against the stems of the plants.