Mint Plant Is Dying

Too Much/Too Little Water

• Mint plants do their best in moist soil, but too much moisture makes the plants more susceptible to disease. The type of climate you live in determines how much water you need to give your mint plants. For example, if you live in a humid, rainy area, hold back on watering, especially if you notice that the plant has symptoms of a fungal infection. If the plant is wilting in a dry, hot climate, provide additional water. Ideally, give the plant between an inch or two of water weekly.

Aphids and Other Pests

• Although mint is generally more pest-resistant than other plants, it can become infested with aphids, cutworms or flea beetles. Cutworms are small larvae that eat their way through the stems of new seedlings. Protect a plant from cutworms by sliding an empty toilet paper roll around the stem. Push the roll just under the soil. Spraying the plant with a blast of water will knock aphids off while covering the mint in the early spring will reduce damage from flea beetles. If those methods are ineffective, you may decide to use insecticides to kill the aphids or beetles.

Diseases

• Verticillium wilt and mint rust are two diseases that commonly affect mint plants. When the plant is suffering from mint rust, it will have orange, yellow or black bumps on the leaves and stems. As the disease progresses, the leaves may die and fall off. Verticillium wilt causes the leaves to yellow and fall from the plant. In mint especially, verticillium wilt makes the leaves on the top of the plant twist and turn a bronze color.

Prevention

• Prevent and protect your mint from fungal diseases by keeping the leaves dry, especially at night, when the weather is cooler. Water the plants at the base, on the soil, and avoid watering the leaves. If the plants become infected, remove any infected parts as well as infected rhizomes to stop the spread of the disease. Try moving healthy plants to a different part of the garden.