A Guide to Disease Controllers in Urban Vegetable Gardens

It’s more than a labor of love; your garden is a symbol of life. Syracuse-area gardens attract pests and disease that cause moderate to severe damage. Controlling diseases before they spread is optimal. Deciding on the best course of action is where it all begins.

Devise a Plan

Planning your lawn and garden maintenance in the spring is the key to success in Onondaga County. If your lawn is in good shape, there’s less chance any diseases will spread to your garden. Map out your garden. Decide which vegetables to plant, and see which vegetables work together as companion plants.

Disease and Pest Management

Before buying any pest control product, you’ll need to check with city codes to be sure it’s legal to use. Some fertilizers and chemical pesticides are not suitable for certain soils. The Cornell University Small Farms Program suggests using organic fertilizers and pest control as often as possible.

Best practice ways to protect from disease and unwanted insects include:

Soil testing for pH balance of alkalinity and acidity. Choose your plants based on moisture and the total sunlight hours they’ll receive. Look at your garden several times a day to see when it gets partial sun and full sun.

  • Plant disease-resistant crops and cultivars.
  • Rotate crops per season.
  • Water the plants at their roots and stems to keep leaves from getting wet.
  • Remove all diseased plants and keep them from touching healthy vegetation.
  • Use clean soil and mulch – disease-infused dirt spreads spores to healthy plants. 
  • Follow state regulations that limit the transport of firewood so your load of campfire wood doesn’t accidentally spread invasive pests.  

Identify the Plant Disease


Knowing which disease is infecting your plants is the first step to fighting it. Climate, environment and nearby vegetation can invite various diseases to your vegetable plant. Here are some of the most common problems.


With small sunken spots and pinkish spores that crop up in cool, wet weather, anthracnose is a fungal disease found on stems, leaves, and fruits. It can cause plants to rot in just a few days. Control anthracnose with liquid copper neem sprays before and during the infection periods — usually in early spring. Remove all severely infected plants and destroy them immediately.

Bacterial Leaf Spot

Small water spots dry up and leave tiny holes in the foliage and fruits. There’s no cure for the infected plants, but you can use copper or sulfur-based fungicides to keep the disease from spreading. 


Early symptoms include black and brown spots on leaves, fruits, and tubers. Late blight occurs after fruiting flowers have blossomed — especially tomatoes and potatoes in wet weather. Prevent blight by using a copper-based fungicide early on, for at least two weeks or during prolonged periods of wet weather. Later in the season, plants may rot and die when there’s too much rain. Try using copper sprays every seven days following heavy downpours.

Club Root

This disease affects crops including cauliflower, broccoli, and cabbage, especially during the heat of the day. Mature leaves turn yellow and drop, and roots become tangled and distorted. Fungicides do NOT work here, because the problem is in the soil. You can prevent the fungus from showing up by keeping a clean garden and rotating crops. To keep this infection from spreading, remove all affected plants immediately, and make sure to wash your garden tools after each use. Weed often to prevent invaders from spreading the disease. You may also have to raise the soil’s pH to a more alkaline mixture.

Downy Mildew

You’ve probably noticed this problem on some of your plants. It appears as a whitish-gray “fluffy” growth underneath leaves and along stems. The best way to prevent downy mildew is to prune plants to promote air circulation. You should also water early in the morning, avoid getting leaves wet, and dispose of severely infected plants. Copper fungicides may work if you catch the disease early. Apply every seven to 10 days.

Powdery Mildew

That white-gray powder shows up on the upper surface of leaves. If the plants are severely infected, they can turn brown and drop. Sulfur fungicides can help, but it’s important to destroy plants that are heavily damaged. 


The two most common kinds are Fusarium and Verticillium. Wilt can damage peppers, tomatoes, melons, potatoes, and other vegetables in your Syracuse garden. High-nitrogen fertilizers make the plants more susceptible, so organic fertilizer is best. You’ll notice the plants start to turn yellow. You can keep the problem from spreading by removing any infected pants and washing your pruning shears afterward. (Bleach and water work well.) Do your best to eliminate pests such as the cucumber beetle which often spreads the disease. Pull any weeds since many varieties host the disease pathogen. Because so many crops are susceptible to wilt, crop rotation doesn’t help the problem. Planting disease-resistant varieties is your best bet.

Controlling Disease in Your Urban Syracuse Garden

There is no one-size-fits-all solution to keeping disease out of the garden — fungal spores spread through air and water. They’re among neighboring trees, vegetation, and in the soil. Improper composting of infected leaves, fruit and stems can lead to more problems and allow spores to winter during the off-season. While you can’t defeat all the infections, you can control disease in your Urban vegetable garden.



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