In general chamomile plants are not particularly susceptible to disease—except as seedlings.
These are a few common diseases that may affect your chamomile plants if you start them from seed:
Botrytis Blight: Older leaves and the center of the plant start to rot. You may see yellow/brown spots on the leaves or water spots on the stems. The fungus will turn fuzzy and gray and will burst in a cloud of spores if you touch it.
What to do: Remove infected plants and debris and throw everything out. Do not ever compost infected plant material.
Damping Off: If you start your plants from seed, keep an eye out for this. The seedlings may emerge and look happy and healthy, and then wham! They wilt and die for no apparent reason. You know what the main cause of this is? Too much water in the soil, or a high level of nitrogen fertilizer. (Remember what we said about not too much water and little if any fertilizer?)
What to do: Keep your seedlings moist, but do not over-water them. Take it easy on the fertilizer. Thin your seedlings so they’re not crowded.
Another treatment is to have some chamomile tea on hand. Brew some until it’s a pale yellow. Then put it in a spray bottle and lightly mist your seeds with it, and let your seeds dry in the sun. Have a batch of chamomile tea on hand to treat your seedlings a few times a week.
Powdery Mildew: This fungal disease gets its name from the way it looks—like a light layer of powder on the plant. Powdery mildew saps the plant’s strength as it struggles to conduct effective photosynthesis.
What to do: Remove and destroy infected plant matter. Make sure your growing area has adequate air circulation and that the humidity in the room is not too high. Remember, fungi love moisture.
Root and Crown Rot: The leaves of the plant may turn yellow, dry up, and whole stems may turn brown and die.
What to do: Remove seedlings from their container. Wash that container with a 10% bleach solution. Replace the soil with fresh potting mix and make sure the soil is well drained.
Water is essential for life; but for chamomile, too much of a good thing can ruin your tea party.
Have you ever had trouble with diseases affecting your chamomile seedlings? How did you treat the infections? Please share your tips for preventing and treating diseases in chamomile plants.