Everyone who gardens will sooner or later have to deal with common diseases of plants and flowers. While some gardeners are luckier than others in this regard, everyone, from the smallest casual gardener to the largest commercial growing operation, has had to grapple with this serious issue.
Both flowering and non-flowering plants are prone to a number of pathogens, including bacteria, fungi and viruses. Fungi are able to survive in the soil, independent of the plants, while both bacteria and viruses require a plant host for their survival.
Fungi are among the most primitive of all organisms, and they are able to reproduce through the use of spores. These spores can be extremely difficult to kill, and the spores are designed to spread rapidly. Fungi produce spores in large numbers, and some of the spores are able to enter plants through their roots, while other spores attach themselves to the leaves of the plant. A single infected plant can release up to 100 million spores, so it is important to completely eradicate any fungal infection.
Unlike fungi, which can lie dormant for years or even decades in the soil, bacteria need both warmth and water to multiply and grow. Therefore, the majority of bacterial diseases are more of a problem in climates that are both warm and wet. Bacterial infections are easily spread through rain, splashing water, and even unknowingly by gardeners as they move between their plants. Most bacteria enter plants through a natural opening like a flower, or through a wound or cut in a stem or leaf.
Viruses are even smaller life forms than bacteria, and they are able to reproduce only from within the cells of the plant or animal they infect. Certain viruses can be transmitted from plant to plant by insects such as aphids, thrips and leafhoppers, while still others can be carried by infected seeds or pollen spores. Like bacteria, viruses often enter plants through cuts or wounds in the stems, leaves or other parts of the plant.
As with all other disease treatment, the first step to effectively treating a viral, bacterial or fungal infection in the garden is to diagnose it properly. Every gardener should keep a book or guide on hand which shows the effects of common plant diseases. This guide will prove invaluable when trying to figure out what is bothering your plants. If you are still stumped for a diagnosis, be sure to seek the assistance of the staff at your local garden center, or the help of a more experienced gardener.
When treating bacterial, fungal and viral infections, the best approach is to try the most natural, least invasive methods first, and to move on only if those natural cures do not produce results. It is always a good idea to keep the use of harsh chemical pesticides and fungicides to a minimum, both for the health of your garden and the health of the wider environment.