Della's Tips

Della is Dinter Nursery's Greenhouse Manager. Della has been with the nursery for 20 years and enjoys sharing her considerable knowledge and experience. She will provide seasonal tips to help you get more from your garden. This month Della offers:

POWDERY MILDEW

Occasionally we all experience the frustration of powdery mildew on a myriad of plants. Especially susceptible are begonias, squashes, pumpkins, cucumbers, and beans. Powdery mildew is recognizable as white powdery spots on leaves. It can spread rapidly, and new growth is especially susceptible. It may not necessarily kill the plant, but it will surely slow and stop growth, and it isn't at all pretty.

Here are a few hints:

  • Avoid excess nitrogen fertilizer. This encourages lots of soft new growth.
  • When planting, plan for good air circulation.
  • Don't water the leaves! Water the ground around the plant. Do not water in the evening. Water in the morning, allowing time for the leaves to dry.
  • Remove diseased leaves where possible.
  • Apply fungicide at the first sign of the disease.

    • When applying fungicide, Never use a systemic product on a food crop. It is always a good idea to start with the least toxic option, if you can. We offer some good products such as Safer's Garden Fungicide. There is a homemade fungicide that uses Neem Oil. Neem is a natural product that is also useful for aphids and other insect pests.

  • 4 tsp. of baking soda or potassium soda (which is better for your soil)
  • 1 tbsp. of Neem
  • 1 gallon of water
    • .

    Mix well and spray. It is better to spray in the early to mid morning. to minimize the potential for leaf burn, and to allow the leaves to dry before evening. Some flowers such as impatiens, hibiscus, and perhaps some roses may be sensitive to neem. There are stronger solutions as well, such as Copper, Bordo Mix and Folpet.

    Always read the fungicide instructions carefully!

    June 2010