Fight garden diseases: mildew and fire blight

Mildew and fire blight aren't pretty nor welcome in your otherwise pristine garden. Here is what all gardeners need to know how to treat.

This dreaded fungal disease is one of the oldest on record. Mildew can be subdivided into two basic kinds: powdery mildew and downy mildew. In both cases, the infection is characterized by a white or gray fungal growth.

• Powdery mildew is a threat to apples, apricots, peas, strawberries, cucumbers, peaches, delphiniums, roses, gooseberries and grapevines.
• Downy mildew is more apt to attack peas, strawberries, lamb's lettuce, cabbages, lettuce, horseradish, radish, black salsify, spinach and onions.
• Powdery mildew usually appears on dry days as a whitish, floury layer on the tops of leaves and flowers, stems and fruit.
• Prevent both by purchasing mildew-resistant strains. Choose a sunny location to grow them and space the plants out well. Plant garlic between them and fortify the plants with horsetail broth.
• For a powdery mildew infestation, cut off sick leaves, shoots and branch tips; they can be composted.
• Downy mildew sets in during damp weather or in a moist greenhouse, and it spreads very quickly. You'll recognize it by the light spots on the top of the leaves and the grayish coating on the underside.
• To prevent downy mildew, buy resistant varieties and avoid planting too close together. Avoid getting water on the leaves. In spring and summer, spray every two to three weeks with horsetail or rhubarb broth. Their high silicic acid content will help combat fungal infestations.
• If plant parts are already affected, remove the entire plant immediately.

Fire blight is an infectious bacterial disease that especially affects stone fruits and various decorative woody plants. It can penetrate even into the heartwood of the plant, so the only remedy is a radical amputation down to healthy wood. Dispose of the lopped-off branches in the household trash, and disinfect tools with rubbing alcohol.