Seaweed  helps to improve the structure and stability of the soil, as the organic components of seaweed meal break down, they provide nutrients for plants and increase the nitrogen content of the soil, it also provides B vitamins like B1 and B12, as well as E, K, and folic acid, which are taken up by plants grown in such enhanced soils. Trace elements, especially iron and calcium, exist in seaweed extract in their chelated forms, which plants can absorb more readily than from plain dirt. Adding seaweed extract increases the amount of chlorophyll in the leaves of plants. Seaweed also contains plant hormones that encourage the growth of foliage. Plants treated with seaweed extract are more resistant to pests like spider mites and aphids. The extract provides some resistance to diseases like scab, mildew, and fungus as well. Enriching the soil with the seaweed strengthens the native bacteria and fungi that provide some of this protection.