The three most common tomato diseases

The three most common tomato diseases

…how to recognize them, combat them, and prevent them

You recently planted your young, healthy tomato plants in the bed – but now the leaves are spotted or you’re struggling with pests? As popular as tomatoes are in organic gardening, they are unfortunately also susceptible to diseases and pests. We explain how to strengthen your plants preventively and what to do in case of illness. This way, a bountiful harvest of healthy, red tomatoes is ensured!

The Top 3 Tomato Problems

1. Late Blight and Early Blight
   • How do I recognize the disease?
     • Symptoms in spring:
       • Lower leaves are affected first
       • Leaves and stems have brown irregular spots
     • Subsequently, a white mold forms on the underside of the leaves
   • Symptoms as the disease progresses:
     • Leaves turn black and fall off.
     • Tomato fruits turn brown and become inedible.
   • What can I do about it?
     • Remove and destroy affected leaves immediately (preferably burn them)
     • ATTENTION: Do not compost them, as the fungus is very resistant and can survive for a long time
     • Disinfect all tools and objects to prevent the spread of fungal spores
     • Harvest fruits prematurely if they do not yet show symptoms
   • How do I prevent it?
     • Since biological control of late blight and early blight is very difficult, well-maintained and strengthened plants are particularly important. Here’s what to consider when growing tomatoes:
       • Avoid generally humid climates with poor ventilation, as this promotes fungal diseases.
       • Rotate tomatoes to a different location every year (sunny and sheltered).
       • Plant tomatoes and potatoes far apart and never next to each other.
       • Maintain sufficient spacing when planting (about 50-70 cm).
       • Use loose, humus-rich soil to prevent waterlogging and ensure optimal nutrient supply (mulching, regular fertilization).
       • Water close to the ground and not over the leaves
       • Remove lower leaves
       • Cover the soil with straw, for example, as the fungal spores live in the soil and are kept away from the plant
       • Additionally, spraying the leaves with horsetail helps. The silica contained therein makes the tomato plant more resistant to fungal diseases.
       • Extra Tip: Pruning the shoots prevents the tomato plant from becoming too dense. This ensures good ventilation and makes it harder for fungal spores to spread.
2. Blossom End Rot
   • How do I recognize the deficiency?
     • Initially, watery spots on the tomato at the former flower attachment
     • Tomato becomes increasingly gray to brown on the underside
     • Eventually, it turns black and falls off
   • What can I do about it? How do I prevent it?
     • To prevent blossom end rot, it is best to use a fertilizer with a high calcium content from the beginning. The easiest way to do this is with bio-fertilizer sticks with an extra portion of calcium. These sticks are simply placed in the soil next to the tomato plant and can be used from pre-growing to ripening phase.
3. Whiteflies
   • How do I recognize the pests?
     • Larvae and flies prefer to sit on the underside of the leaves
     • When the plant is touched, they fly up in swarms
     • Larvae: white to transparent color, immobile
     • Flies: 2-3 mm in size
   • Effects on tomato plant:
     • Stunted growth
     • Leaves curl and deform
     • Sticky secretion from whiteflies can develop into the fungal disease sooty mold, which is very harmful to the tomato plant
   • What can I do about it?
     • Hang yellow sticky traps or yellow sticky cards:
       • the flies are attracted by the yellow color and get stuck on them
     • Regularly ventilate the greenhouse for good air circulation
   • How do I prevent it?
     • Regularly check the undersides of leaves
     • Spray tomato leaves on the upper and lower sides with nettle extract to strengthen them
     • Underplanting with basil keeps whiteflies away and protects against powdery mildew
     • Extra Tip against Aphids on Tomatoes
       • Aphids are among the most common pests. Even with tomatoes, infestations occur repeatedly. Our tip: Prevention and strengthening of the tomato plant with garlic extract!
       • Aphids do not like the smell of garlic
       • They disappear from the plants and infest them less frequently
       • Garlic additionally strengthens the cell walls and promotes the overall vitality of the tomato plant
       • Similarly, keeping ants away can minimize aphids, as ants carry aphids to the plants. Therefore, set up ant bait stations or sprinkle diatomaceous earth powder.

Further Tips for Healthy Tomatoes

• Optimal soil conditions: A healthy soil with active soil life is the basis of every healthy plant. Therefore, supply your soil with organic material such as compost. Use a special organic tomato soil when planting to provide your tomatoes with all the important nutrients right from the start. Use soil improvers and microorganisms to further promote soil life.
• Consider crop rotation and mixed cultures: Tomatoes are heavy feeders and should never be planted in the same location for several years. Mixed cultures protect plants from diseases and pests. For example, basil protects tomatoes from powdery mildew