Powdery Mildew

Underwatering

Powdery mildew, a fungal disease, thrives when the plant is stressed, including from underwatering. To manage this, ensure your rosemary receives consistent, adequate watering, allowing the soil to dry slightly between waterings but not to the point of stress. Improve air circulation around the plant to reduce humidity and fungal spore viability. If infection occurs, remove affected parts and treat with a suitable fungicide, following label instructions. Preventatively, applying a baking soda solution (1 teaspoon per quart of water) can offer some protection.

Spider Mites

Tiny spider-like pests that suck sap from the leaves, causing them to turn yellow and drop.

To manage spider mites, start by rinsing your rosemary plants with a strong jet of water to dislodge the mites. For persistent infestations, apply neem oil or insecticidal soap directly to the affected areas, ensuring thorough coverage of both sides of the leaves. These treatments are most effective when applied in the cooler hours of early morning or late evening to avoid leaf burn. Regular monitoring and early intervention are key to preventing severe damage.

Powdery Mildew

Fungal infection caused by various fungi, thriving in both high humidity and dry conditions.

To manage powdery mildew, it's crucial to ensure good air circulation around your rosemary plants. Prune them regularly to remove infected parts and dispose of them properly. Avoid overhead watering to reduce humidity levels around the foliage. For severe infections, apply a fungicide suitable for edible plants, following the manufacturer's instructions closely. Implementing preventive measures, such as choosing resistant varieties and spacing plants adequately, can also significantly reduce the risk of powdery mildew.