Summer has arrived, and with it comes all of our favorite summer garden veggies! Everything is growing really well, looks great, and then one day you check on your garden and you see yellowing leaves.

If your like me the first year I tried growing a veggie garden, you might think it could be from a bit of stress from the "less than perfect" watering method or from a bug or too much heat, so you just let it be for now.

Next thing you know it seems to be on every plant, and getting worse and worse! Garden fail incoming, right?!

But it doesn't have to be that way, there are ways to deal with the issues and still have your garden succeed! Let's look into the steps you can take to mitigate the problems

Step 1 - Indentify the problem

Tomatoes in particular seem to be problem magnets. Here is an extensive list of common issues they are susceptible to:

Diseases

1. Early Blight

Symptoms: Dark spots on older leaves, yellowing, and leaf drop.

Cause: Fungus (Alternaria solani).

2. Late Blight

Symptoms: Dark, water-soaked spots on leaves and fruit.

Cause: Fungus (Phytophthora infestans).

3. Septoria Leaf Spot

Symptoms: Small, circular spots with dark borders on leaves.

Cause: Fungus (Septoria lycopersici).

4. Fusarium Wilt

Symptoms: Yellowing and wilting of leaves, often starting on one side.

Cause: Fungus (Fusarium oxysporum).

5. Verticillium Wilt

Symptoms: Yellowing of leaves, stunted growth.

Cause: Fungus (Verticillium spp.).

6. Anthracnose

Symptoms: Sunken spots on fruit.

Cause: Fungus (Colletotrichum spp.).

7. Tomato Spotted Wilt Virus

Symptoms: Bronze or dark spots on leaves, ring patterns on fruit.

Cause: Virus spread by thrips.

8. Bacterial Speck

Symptoms: Small, dark, raised spots on leaves and fruit.

Cause: Bacteria (Pseudomonas syringae).

9. Bacterial Spot

Symptoms: Water-soaked spots on leaves and fruit.

Cause: Bacteria (Xanthomonas campestris).

10. Bacterial Canker

Symptoms: Wilting, browning of leaf edges, cankers on stems.

Cause: Bacteria (Clavibacter michiganensis).

Pests

1. Aphids

Symptoms: Curled leaves, sticky residue (honeydew).

2. Tomato Hornworms

Symptoms: Large holes in leaves, defoliation.

3. Whiteflies

Symptoms: Yellowing leaves, honeydew.

4. Spider Mites

Symptoms: Tiny yellow spots, webbing.

5. Cutworms

Symptoms: Seedlings cut at soil level.

Physiological Disorders

1. Blossom End Rot

Symptoms: Dark, sunken spots on the blossom end of the fruit.

Cause: Calcium deficiency, inconsistent watering.

2. Cracking

Symptoms: Cracks on the fruit, especially after heavy rain.

Cause: Rapid growth due to fluctuating water availability.

3. Sunscald

Symptoms: White, leathery patches on fruit.

Cause: Exposure to intense sunlight.

4. Catfacing

Symptoms: Misshapen fruit with scars.

Cause: Cool temperatures during fruit set.

5. Leaf Roll

Symptoms: Rolling or curling of leaves.

Cause: Environmental stress, over-pruning.

Step 2 – Treat the issue

Now that you’ve identified the issue, here’s how you can tackle each problem:

Diseases

1. Early Blight

Remove and destroy infected leaves, avoid overhead watering, apply fungicides (e.g., chlorothalonil, copper-based fungicides).

2. Late Blight

Remove and destroy infected plants immediately, apply fungicides (e.g., copper-based fungicides), ensure good air circulation, avoid overhead watering.

3. Septoria Leaf Spot

Remove and destroy infected leaves, apply fungicides (e.g., chlorothalonil, copper-based fungicides), practice crop rotation.

4. Fusarium Wilt

Remove and destroy infected plants, solarize soil to kill the fungus, use resistant varieties, rotate crops.

5. Verticillium Wilt

Remove and destroy infected plants, solarize soil, use resistant varieties, rotate crops.

6. Anthracnose

Remove and destroy infected fruit, apply fungicides (e.g., chlorothalonil, copper-based fungicides), avoid overhead watering, mulch to prevent soil splash.

7. Tomato Spotted Wilt Virus

Remove and destroy infected plants, control thrips with insecticides (e.g., spinosad), use resistant varieties, practice good garden hygiene.

8. Bacterial Speck

Remove and destroy infected plants, apply copper-based bactericides, avoid overhead watering, rotate crops.

9. Bacterial Spot

Remove and destroy infected plants, apply copper-based bactericides, avoid overhead watering, rotate crops.

10. Bacterial Canker

Remove and destroy infected plants, disinfect tools, avoid overhead watering, rotate crops.

Pests

1. Aphids

Use insecticidal soap or neem oil, encourage or purchase natural predators (e.g., ladybugs), spray with a strong stream of water to dislodge.

2. Tomato Hornworms

Handpick and destroy, use Bt (Bacillus thuringiensis), encourage natural predators (e.g., birds).

3. Whiteflies

Use yellow sticky traps, insecticidal soap, neem oil, encourage or purchase natural predators (e.g., ladybugs).

4. Spider Mites

Use miticides, insecticidal soap, neem oil, keep plants well-watered to reduce stress.

5. Cutworms

Use protective collars around seedlings, spread diatomaceous earth around plants, encourage natural predators (e.g., birds).

Physiological Disorders

1. Blossom End Rot

Ensure consistent watering, add calcium to the soil (e.g., crushed eggshells, calcium nitrate), mulch to retain moisture.

2. Cracking

Water consistently, mulch to retain moisture, choose crack-resistant varieties, pick fruit promptly after rain.

3. Sunscald

Provide shade for fruit during intense sunlight, avoid excessive pruning that exposes fruit, use shade cloth if necessary.

4. Catfacing

Avoid planting too early in the season, use row covers to protect young plants from cold, choose catface-resistant varieties.

5. Leaf Roll

Avoid over-pruning, ensure consistent watering, mulch to retain moisture, avoid heavy nitrogen fertilization.

General Tips for Prevention

• Crop Rotation: Rotate your tomato crops with non-solanaceous crops every year to prevent soil-borne diseases.

• Sanitation: Keep the garden clean by removing plant debris and weeds, and disinfect tools regularly.

• Proper Spacing: Space plants adequately to ensure good air circulation.

• Watering Techniques: Water at the base of the plants rather than overhead, and water in the morning to allow leaves to dry out during the day.

• Resistant Varieties: Choose disease-resistant tomato varieties when possible.

By following these steps, you can effectively manage and prevent issues in your tomato garden, ensuring a healthy and productive crop.

Happy gardening!