Preventing Garden Diseases

A tomato plant affected by Septoria.

As the gardening season winds down it is appropriate to evaluate the health of your garden and consider measures to manage plant diseases for next year. Because plants can be impacted by bacterial, viral and fungal disease, there are cultural practices that can help prevent problems in your garden.

Tomatoes seem to be the biggest problem. Since seeds may carry pathogens, select varieties that are resistant to problems exhibited in your garden. For example, there are seeds available that have resistance to Septoria which commonly occurs in our area. We have trialed with some encouraging results Defiant, a variety from Johnny’s Seeds, and Iron Lady from High Mowing Organic Seeds.

Keeping the weed pressure managed helps reduce conditions that harbor plant diseases. Spacing plants according to recommendations on the plant label or on the seed package is strongly encouraged to avoid spreading diseases through your garden. Plants need good air circulation to reduce fungal problems. Rotating your plant families is a best practice that avoids infecting next years’ plants with soilborne diseases.

When your garden plants show signs of disease issues, it is important to sanitize your tools and footwear with a diluted bleach solution after every garden visit. This habit will minimize disease spread between plants. At the end of the season perform a thorough clean-up in the garden to eliminate plant material that could harbor disease over the winter.

Attention to watering methods can manage the spread of foliar disease. Minimize overhead watering with hoses or sprinklers. Instead, consider a drip irrigation approach so that leaves remain dry and are not splashed with soil. Using a watering can at the base of plants is another way to keep water off the leaves. Try not to work in the garden when plants are wet to prevent facilitating the spread of fungal problems.

Next spring have patience with getting your garden started. Proper soil temperature is essential for keeping plants healthy. Cold soil can be a shock to warm weather plants making them prone to disease. Even though following all of these practices is not a guarantee of a garden that will be disease free next year, you will position yourself to have healthier plants.