5 Tips to Prevent Leaf Blight

Leaf BlightIs your garden suffering from leaf blight? If you like to grow fruits and vegetables from the Cucurbitaceae family, also called Cucurbits, which refers to many popular members of the gourd family, including but not limited to melons, pumpkins, squash and cucumbers, then leaf blight is something you may encounter along the way.


Leaf Blight, also referred to as Alternaria cucumerina, is a fungal disease in plants that causes dark brown spots on their leaves. When the host plant is infected with this disease, defoliation of the plant will occur which in turn leads a plant to a reduction in fruit yields and can also cause fruit to ripen too early.



As is the case with most other fungal plant diseases, leaf blight occurs when these fungal spores end up on your plant?s leaves and germinate during periods of moist humid weather. Wet leaves on your plants also create a great environment for the disease to germinate and spread.

Leaf Blight


Normally leaf blight will target plants when they are young, or when they are old. Rarely does this fungal disease hit plants during mid growing season. If it does, then chances are your soil is not healthy, lacking the necessary nutrients that your plants need, creating an environment where your plants will not grow healthy to begin with.

5 Tips to Prevent Leaf Blight 

1] The first thing you need to do is to make sure you have healthy soil. This begins long before you plant by mixing in plenty of organic matter such as homemade compost or well aged manure. Your soil is the foundation of your garden and keeping it healthy is a top priority to not only fight leaf blight, but many other diseases as well.

2] Remove infected plants and discard of them in your regular trash. Do not throw these plants in your compost pile as they can overwinter. Unfortunately, this fungal disease can survive over the winter as mycelium, which is the vegetative portion of the fungus consisting of a network of branching filaments.

3] Always water your plants at the soil level. Soaker hoses and drip lines work great for this application. Because wet leaves are a great environment for leaf blight, avoid watering your plants from overhead, and if you must do so, water first thing in the morning so that the leaves will have plenty of time to dry, as opposed to at night, when the water can sit on the leaves for quite some time.

leaf blight

4] Rotate your plants every garden season and make sure you are not following members of the same family. The easiest way to destroy your crops from one season to the next is to plant the same items (or similar varieties) in the same spot every year. That is a bad bug, plant disease dream come true. Follow Cucurbits with leafy veggies such as spinach, lettuce, kale, or root crops like carrots, beets or onions.

5] Feed your plants. I cannot stress this enough. Even though you may have mixed in plenty of compost into your soil, you still need to feed your plants on a weekly basis. A good way to feed your plants is to use fish emulsion, compost tea or even adding compost around the base of your plants. Regular feedings will help keep your plants healthy.

Making the right choice for healthy plants 

Along with these 5 tips, if you are experiencing leaf blight on a yearly basis, you may want to consider varieties of Cucurbits that have been proven to be resistant to this fungal disease. Check with a local garden center and see what they recommend for your area.


leaf blight



About the Author Mike the Gardner
Mike Podlesny is the author of the book Vegetable Gardening for the Average Person as well as the creator of the Seeds of the Month Club where members receive non gmo, heirloom variety seeds every month. You can listen to Mike each week on the Vegetable Gardening Podcast where he interviews gardening industry experts.

Shared on the following blog hops and linkys. Mountain Woman Rendezvous, Backyard Farming Connection, From the Farm Friday, Simple Saturdays