There are several ways to use cinnamon for plants:

1. Sprinkle cinnamon on the soil: You can sprinkle cinnamon on the soil before planting to prevent the appearance of diseases. Sprinkle a thin layer of cinnamon over the soil and mix well before planting.
2. Apply cinnamon to the roots: Cinnamon can also be applied directly to the roots of plants to improve their growth and health. Sprinkle a small amount of cinnamon on the roots before planting or mix a small amount of cinnamon into the water before watering the plants.
3. Spray cinnamon solution on leaves and stems: Mix a small amount of cinnamon in water and spray the solution on the leaves and stems of plants to help prevent diseases and improve plant health. You can also mix a small amount of cinnamon in some oil and apply it to the leaves and stems to protect the plants from insects and pests.

It is important to remember that, although cinnamon is a natural and safe option for plants, it should be used in moderation. Too much cinnamon can be harmful to plants and can cause nutrient overload. As always, it is important to test a small section of the plant before applying cinnamon to the entire plant to make sure it does not cause harm.