Marigold Leaf Dotting Explained
Some marigold leaves have small regular purple dots. This is likely due to the pores on the leaves, known as stomata. It is a normal characteristic of certain marigold cultivars and should not be a cause for concern. If the dots were caused by a disease, pest, or fungus, the pattern would be irregular and not present on every leaf.
| Cause | Pattern |
|---|---|
| Normal characteristic | Regular purple dots on every leaf |
| Disease, pest, or fungus | Irregular pattern |
Over-Transpiration Concerns
However, if the purple dots are accompanied by wilting or other signs of stress, it may be a sign of over-transpiration. Over-transpiration can occur when there is excess moisture and heat, causing the plant to lose more water than it can take up. Ensuring the soil dries out between waterings may help to prevent this, but if the plants are otherwise healthy and growing as expected, the purple dots should not be a major concern.
If the purple dots persist, it may be a sign of nutrient deficiencies. It is important to check the soil for a lack of phosphorus and consider using bone meal or an all-purpose fertilizer to ensure the marigold seedlings are getting the necessary nutrients.
Addressing Marigold Discoloration
A nutrient deficiency, particularly a shortage of phosphorus, can cause the leaves and petioles of marigolds to turn purple. This can be addressed by using bone meal or an all-purpose fertilizer that includes phosphorus to ensure the marigolds are getting the necessary nutrients.
To address a nutrient deficiency:
- Use bone meal.
- Use an all-purpose fertilizer that includes phosphorus.
However, it is important to note that not all purple leaves on marigolds are a cause for concern. Some marigold cultivars naturally have purple leaves, while others may turn purple due to environmental factors such as over-transpiration.