blight on tomatoes

It is heartbreaking to invest so much in your vegetable garden only to watch it fall victim to pests and diseases. The truth is there is no such a thing as the perfect garden. In this post, we will look into the most common diseases we may encounter in the vegetable garden and how to deal with them.

There are three main factors that contribute to the development of diseases in a garden.

  • A susceptible host: It is the plant that provides the basic elements for the disease to thrive.
  • The pathogen: This is the disease itself that develops whenever the right elements are available.
  • The environment: These are the natural elements surrounding the plant, including temperature, humidity, soil, wind, and light.
How to deal with the most common diseases in the vegetable garden.

Identify the disease

When it comes to plant-related diseases, it is somewhat tricky for new gardeners to identify. It takes some experience to get to know the different symptoms related to a given disease.

#1 Blight

Blight is mostly common in tomato and potato plants. It manifests as a brown spot surrounded by a yellow halo. It spreads fast, destroying the foliage leaving the fruits exposed. There are three types of blight: early blight, fire blight, and late blight. They all end up making the plant look like it was set on fire and can also affect the fruits.


It is caused by fungi that thrive when the weather is warm and humid. The spores are carried by insects, animals, wind, and water.


  • Choose disease-resistant varieties. But if you are an avid heirloom grower, you might not have that luxury.
  • Keep your garden clean from debris.
  • Increase airflow in between the plant by spacing the plant properly and pruning the old leaves regularly.
  • Water in the mornings to allow the soil and plants to dry during the day.
  • Exercise crop rotation to turn the area unfavorable to the pathogen.
  • Clean your tools and hands clean and sanitized to prevent cross-contamination.


There are no effective treatments for blight or any fungal disease, for that matter. By the time the symptoms appear on the plant, the disease is already set and spreading. However, you may use a copper-based fungicide to slow down the spread and allow the plant time to produce.

For organic growers, keep cleaning the plant from damaged parts and throw them away. If the damage is unsalvageable, take it out and discard it. It is important to take notes and avoid planting the same variety the following year.

How to deal with diseases in the vegetable garden.

#2 Blossom-end rot

Blossom-end rot is not classified as a disease since it is caused by growing condition. However, it does open up the door to a disease called mold that can destroy the plant.

Blossom-end rot affects many fruiting plants such as tomatoes, eggplant, zucchini, and peppers. It shows up as a dark brown spot at the base of the young fruit.


This disorder is a sign of calcium deficiency. It is commonly thought that poor soil is the main reason. While that might be true, the main cause is the plant’s inability to absorb the calcium from the soil due to irregular watering.


The most important step to prevent blossom-end rot is by avoiding sporadic watering. Stressing the plant by letting it go dry then flooding it prevents its cells from working adequately.


There is no treatment for blossom-end rot other than improving watering practices.

damping off

#3 Damping-off

Damping-off affect mostly seedling, but it can affect newly planted transplants. At the base of the plant, the stem looks pinched and dry making the top flop over.


It is another fungal disease borne in soil. It thrives is damp area, hence the name.


  • Replenish soil with fresh compost.
  • Water in the morning to allow the soil to dry out.


Unfortunately, there is no cure for damping-off. Once it gets the plant there is no way of saving it.

#4 Powdery mildew

Powdery mildew is another fungal disease that affects many plants, especially zucchini, cucumber, calendula, and zinnias. It appears as a grey or white powder-like spot on the leaves.


Powdery mildew is caused by a fungal infection. It thrives in warm and humid climates. Low sunlight and poor air circulation also promote its spread.


  • Choose mildew-resistant varieties.
  • Avoid crowding plants for better airflow.
  • Plant in a full sun location.
  • Keep the plant healthy by pruning old and affected leaves.
  • Spray a 40/60 ratio of milk to water solution to prevent mildew.


There are a few homemade remedies you may try to combat powdery mildew. However, they are more effective as preventatives rather than treatment.

  1. Baking soda solution: 1 tablespoon baking soda+ 1/2 teaspoon natural soap+ 1 gallon of water. Mix the solution well before spraying it liberally on the affected leaves.
  2. Milk solution: Mix one part milk to two to three parts water, then spray on the affected leaves.
  3. Sulfur-containing fungicides: these are commercially available and may be more effective. Read the label to make sure you are comfortable with the ingredients.

#5 Rust

Rust manifests in the form of reddish spots on the leaves. It affects mostly beans in the home garden. Although it does not kill the plant, it still affects its vigor and flower production.


Rust is a soil borne fungal disease, that thrives in warm and humid climates. The spores spread from the infected plant to the healthy ones by water, wind, or leaves rubbing.


  • Remove affected leaves as soon as possible and discard.
  • Keep tools and hands clean.
  • Avoid crowding your plants.


There is no home remedy for rust, but you can try fungicide spray.

Leave a Reply

Your email address will not be published.