Verticillium Wilt, often called Maple Wilt, is a common disease that attacks many types of trees. It is caused by a soil-inhabiting fungus called Verticillium. The fungus can spread through plant-to-plant contact, soil, groundwater, and often via infected pruning equipment that has not been properly sanitized. The disease usually enters the tree through the soil but can also enter through wounds. Once inside, the fungus spreads throughout the tree’s vascular system, eventually blocking it and preventing the tree from properly moving water and nutrients.

Symptoms:

• The first signs are yellowing and browning of leaves at the ends of some branches.

• Initially, the yellowing and browning is spotty and irregular throughout the tree.

• As the fungus spreads, leaf browning becomes more severe and widespread.

• New leaves may be absent, undersized, or yellowed.

• Infected trees may die branch by branch over several seasons.

• Symptoms are more severe during droughts when the tree’s vascular system is stressed.

Recommended Control Steps:

• Pruning: Remove all dead wood a few inches below diseased areas to eliminate as much fungal concentration as possible. Do not remove branches that have recently wilted, as they may reflush. Sanitize pruning tools after each cut.

• Fertilizing: Apply a slow-release nitrogen blend. Using a TreeHelp Annual Care Kit is recommended, as it provides fertilizer, mycorrhizal treatment, and biostimulants to help the tree absorb and use water and nutrients effectively.

• Watering: Provide deep root watering 2–3 times per week. Water should penetrate 24–36 inches into the soil to hydrate the entire root zone. For large trees, use a sprinkler or soaker hose over the tree’s drip line for about 2 hours. Deep root watering is more effective than frequent shallow watering.

• Drought Support: During extreme drought, consider using Hydretain Root Zone Moisture Manager to help retain moisture in the root zone and reduce drought stress.