In the humidity of the growing season, garden hygiene is of utmost importance in order to keep plants free of fungi. Prevention is the best treatment for fungal infection, whether it be spotting or mildew. Much like the way humans can be affected by Athlete’s Foot or ringworm, fungal disease can be exacerbated in the garden by moist, warm conditions. The summer months put plants at a higher risk due to these factors. Luckily, there are a number of methods to reduce the chance of fungal disease.
One of the most common kinds of fungus that affects plants is mildew. Powdery mildew, which looks like a thin white or gray coating on leaves and shoots, is an infection that will slow growth but rarely kill plants. Downy mildew, which is white or purple and appears on stems and the undersides of leaves, is much more serious and can kill plants quickly. Varieties like lilac, pulmonaries, asters, delphiniums, and phlox are susceptible to powdery mildew, while downy mildew can affect aster, veronica, and many kinds of vegetables. Another common fungal problem is leaf spot, which can be caused by several different kinds of fungi. Leaf spot appears as dark, tan, or gray splotches and can even leave holes in the leaves. Spotting can take the life of the plant, if the infection is serious.
One of the best ways to avoid fungal disease in the garden is to prune and weed regularly. Removing affected leaves or shoots that show signs of fungi is an important way to make sure infection doesn’t spread from leaf to leaf or plant to plant. Be sure to use clean pruning shears and only cut dry plants. Wet plants present a favorable environment for bacteria and fungi, so a freshly cut stem that is is prone to a rapidly spreading infection. Look for leaves that are spotted or have holes, or sections of plant that seem to have powdery film on them. Remove whatever is affected, even if it means that an entire plant is beyond saving. It may just save the rest of the garden.
Weeding is important, as well. Because weeds are hardy enough to grow where they aren’t wanted, they can often carry diseases that do not affect them but can damage a carefully constructed garden. Weeds also block sun from reaching the bases of plants, which traps the moisture that feeds these infections.
One of the most important prevention methods is to be deliberate when watering. Rather than spraying leaves and flowers, plants should be watered around the base. The plants’ roots in the soil are what absorb the water, not their leaves. The extra moisture on their surface area, especially in hot weather, is an invitation for infection. Keeping the leaves dry and allowing the water to be soaked up where it is useful will prevent fungal growth, and feed the plant more efficiently. These simple steps will keep plants fresh and free of fungus.