My Dahlia Is Looking Unhealthy. What are the most Common Pests and Diseases that Could Attack Dahlia and is there Anything I can do to Help it?

On closer inspection, do you see any pests on your flowers?

Can you identify larger pests that feed on Dahlia like caterpillars, slugs or snails, or bite marks on leaves?

Using a magnifying glass, can you see and clusters of small yellow bugs under the leaves and/or on the new plant growth?

Using a magnifying glass, can you see tiny, slender green or yellowish bugs on the leaves and/or flowers of your Dahlia?

Using a magnifying glass, can you see tiny black or red bugs that resemble spiders?

Using a magnifying glass, can you see small bugs with elongated bodies and wings that are positioned like a roof over their backs?

Do you see a white powdery growth on the upper surface of leaves, stems or flowers of your Dahlia?

Have the leaves or flowers of your Dahlia developed a white growth, which later turned dark gray?

Can you see mottled foliage or ring-spots on the Dahlia's leaves?

Can you see a white ring around the Dahlia's stem in the soil?

You can get rid of larger pests like caterpillars, slugs or snails by removing them by hand. Protect your plant from further pest attacks by using diatomaceous earth (natural pesticide) in your garden.

Your Dahlia is being attacked by aphids. You can get rid of them by using any approved insecticide, but before you resort to that, try using more environmentally friendly solutions like neem oil or by introducing natural predators like ladybugs to your garden.

Your Dahlia is being attacked by thrips. You can get rid of them by using any approved insecticide, but before you resort to that, try using more environmentally friendly solutions like neem oil or insecticidal soap.

Your Dahlia is being attacked by a species of plant mites. You can get rid of them by using any approved miticide, but before you resort to that, try using more environmentally friendly solutions like neem oil or horticultural oil spray.

Your Dahlia is being attacked by a species of leafhoppers. Get rid of them by using any approved insecticide spray. This should be done with caution as insecticides can be toxic to humans and pets, and also can reduce the number of useful insects in the garden. Leafhoppers can be carriers of a much more dangerous virus that causes Aster yellows disease. If your plant continues to show signs of sickness even after you got rid of leafhoppers, you'll need to get rid of the plant as well, as Aster yellows is untreatable.

Your Dahlia is suffering from a fungal disease called powdery mildew. To treat your plant, cut off the affected foliage, burn it to prevent the spreading of the fungi and increase air circulation around the plant by pruning.

Your plant is suffering from a fungal disease called a grey mold or Botrytis blight. To treat your Dahlia, cut off the affected foliage, burn it to prevent the spreading of the fungi and increase air circulation around the plant by pruning.

Your plant is suffering from a viral infection. Viruses circulate internally in plants so there is no effective way of curing the plant. Get rid of the affected plant as it can infect more plants around it.

Your plant is suffering from a fungal disease called stem rot. If you have identified it in the early stages, you might have a chance of saving your plant. Remove the Dahlia from the soil, and gently wash the roots under running water to wash away as much soil as you can. Cut all affected roots. Treat the soil with fungicide and put the affected plant in a pot as you may need to repeat the process all over.

Many environmental issues could have caused your Dahlia's unhealthy look. Deficiency in nitrogen and phosphorus or deficiency in iron, inadequate lighting or watering, sunburn or freeze damage. Make sure that your plant has all the necessary and optimal conditions for growth and it should recover.