Downy mildew reared its ugly head here on Long Island last summer, and it looks like it might be back. If your plants become infected, you cannot and should not eat the basil. There will be no options besides ripping up the plant, root and all, and discarding it in a tightly sealed plastic bag.
But the Burpee company is offering some preventive steps you can take to minimize the chances your plants will be affected. Here are their tips:
1. Grow basil in a sunny location Sources say that basil grown in sunny areas are far less troubled than those grown in shadier beds.
2. Give basil adequate space to grow. Be sure to give the basil plants adequate space in the garden bed or container to promote good air flow. It may be a design trend to plant lettuces and basil closely together, but it is not the best method for cultivating healthy plants under tougher than normal growing conditions.
3. Always water early in the morning and water above the roots. Since the disease thrives in wetness and humidity, it is best to water in the morning so that any excess water that may get on the leaves evaporates quickly. Also, it is essential to direct water over the plants roots when watering to minimize moisture on the leaves. Never water above the plant.
4. Plant disease-resistant varieties. The commonly grown sweet basil and Thai types are more susceptible than other basil species. Some gardeners have reported that lemon and purple basils seemed more resistant to the current strain of blight. Pepper basil and spice basil have not yet been affected.