Simply wash the black away with a strong spray from the hose.
When you see evidence of pests, you can also spray an insecticidal soap on the leaves, especially the underside. Spray early in the day so the spray doesn't burn the leaves. See our Aphids link above for more information.
Simply wash the black away with a strong spray from the hose.
When you see evidence of pests, you can also spray an insecticidal soap on the leaves, especially the underside. Spray early in the day so the spray doesn't burn the leaves. See our Aphids link above for more information.