A few guidelines to remember is to sterilize pots before you re-use them. Also, do not re-use old soil mix. Put new seeds or plants in new soil mix. Make sure the tray or container has adequate drainage holes and, from time to time, disinfect your garden tools.
Many gardeners use commercial products to spray on their sick plants, but if you are growing organic and want a more natural way to treat them, then try using cinnamon. The anti-fungal and anti-bacterial properties in cinnamon, help inhibit the growth of certain bacteria and fungi.
The video below shows how to sprinkle cinnamon on your seedlings.
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