What Causes Black Spots on Dahlia Leaves and How to Handle Them
The editor will discuss the causes and treatment methods for black spots on dahlia leaves, sharing some knowledge about flowers. Let's take a look together.
What Causes Black Spots on Dahlia Leaves and How to Handle Them
Black spots on dahlia leaves might be due to low ambient temperatures causing frost damage, excessive watering, or improper care. If there are black spots on the leaves, remove the diseased leaves, keep the dahlia in a well-ventilated area, expose it to sunlight during the day, bring it indoors at night, and spray with a 800x dilution of methyl thiophanate. Reduce watering and increase nitrogen fertilizer to help the leaves recover quickly.
What Causes Black Spots on Dahlia Leaves
Black spots on dahlia leaves are generally caused by low ambient temperatures, which the plant is not adapted to, leading to frost damage, or excessive watering.
Dahlia Leaf Black Spots Due to Sunburn?Dahlia leaf black spots are not caused by sunburn but are likely due to improper watering and incorrect daily care methods.
What to Do When Dahlia Leaves Have Black Spots
When there are black spots on dahlia leaves, remove the diseased leaves promptly to prevent more leaves from being affected. Then move the dahlia to a well-ventilated area for care, expose it to sunlight during the day, and move it indoors at night. In addition to adjusting care, you can also use medication for treatment.
What Medication to Use for Dahlia Leaf Black Spots?When dahlia leaves have black spots, promptly remove and burn the diseased plants. You can spray with a 1000x dilution of 50% malathion or a 1500x dilution of 40% dimethoate. Besides spraying, you can use a 25% carbaryl 800x dilution to prevent the spread of other pests.
Preventing Black Spots on Dahlia Leaves
To prevent black spots on dahlia leaves, strengthen cultivation management, avoid planting too densely, increase ventilation and light exposure, water from the base to prevent water splash, and ensure timely drainage of accumulated water during rain.
This article shares the causes and treatment methods for black spots on dahlia leaves, hoping to bring a little help to your life!