Is the white stuff a bug?

No, it is a fungus. It looks like someone sprinkled flour on your plant.

Should I throw the plant away?

Not necessarily. If you catch it early, you can prune the bad leaves and treat the rest to save the plant.

Pot Marigold: spots, causes and fixes

Check these first

Look for a white, powdery substance on the leaves.
Check if the plant is crowded by other plants.
Feel if the foliage stays wet for long periods.

Likely causes

Powdery mildew
Most likely
How to tell: You will see a white, flour like dusting on the leaves and stems. It usually starts on older leaves and spreads upward.
What to do: Remove the most heavily infected leaves and dispose of them in the trash. Spray the remaining foliage with a mixture of one tablespoon of baking soda in a gallon of water.
High humidity and poor airflow
Possible
How to tell: The fungus grows rapidly when nights are cool and days are humid. Lack of wind or space around the plant prevents moisture from evaporating.
What to do: Thin out your plants to improve airflow. Always water at the base of the plant rather than overhead to keep the leaves dry.

Leaf spots on other plants

Find out what's wrong with your pot marigold

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

When to worry

If the mildew covers most of the foliage, the plant will struggle to photosynthesize and may stop blooming. Treat it as soon as you see the first spot.

Stopping it coming back

Plant in full sun with plenty of space between plants to ensure good air circulation. Water only at the soil level, never over the leaves.

Pot Marigold: spots? Check yours with a photo

Every plant is a little different. Take a photo of your pot marigold and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

Get the app · Or check it from a photo now, free

Questions people ask

Is the white stuff a bug?: No, it is a fungus. It looks like someone sprinkled flour on your plant.
Should I throw the plant away?: Not necessarily. If you catch it early, you can prune the bad leaves and treat the rest to save the plant.

Guides to these causes

Powdery Mildew

Why are there white spots on my pot marigold?