There’s no completely natural remedy for you to get rid of anthracnose from plants. However, you can try and save plants by immediately pruning infected parts if an infection does occur. You should also clear away debris from under the plant as spores might be present in said debris. It would also help to water the base of plants instead of the leaves and flowers. Fungicides are also recommended for preventing anthracnose infection. You can use organic fungicides to keep your garden protected in a somewhat natural manner.