There is a concentric ring on a tomato leaf. Those concentric rings is more than just a cosmetic flaw; they’re a distress signal that the plant is fighting a disease. Instead the leaf appears as if someone shot at it, and now it’s a target board. Those rings mean the plant are in trouble from a disease, which by this point is well underway.
What can you do? Examine your garden beds before they shows signs of anything wrong. Many gardeners wait until there is a problem. Try to prevent disease before there is one.
How to Stop Plant Diseases
The majority of plant diseases in your outdoor garden are caused by fungi. They’re the primary issue for fruits and vegetables. Bacterial pathogen spread quickly; often via rain, and move fast. Vascular wilts kills from within. What type of pathogen is it? You can’t spray a fungicide on a bacterial disease. Know your enemy before spraying.
Don’t water the foliage but the soil, because moisture on the leaves creates a nursery for spores. Keeping them off the leaf will help prevent an outbreak; make it dry there. The risk rise if dew remains on the leaves beyond noon. Changing that behavior, plus thorough cleaning of tools, is better than any chemical and eliminates more disease. Clean your pruners! Dirty tools spread bacteria fast, they can carry the infection from one healthy plant to another.
Control of diseases starts with prevention. Rescue spraying come as a last resort. First, work on selecting the right location and air flow. Second, select resistant varieties of plants. These will have some built-in resistance. They don’t get stressed out as much as others.
Third, air flow matter. Humidity gets trapped in crowded plants. It helps blight and mildew to grow. Give your plant room to breathe. Stop giving the disease a place to hide.
Act fast if there’s any sign of disease showing up. Check the undersides of leaf each week. Remove infected tissue, which will stop its spread. Bag up the sick stuff. Toss. Don’t compost. Composting sick plants would of cause trouble next year.
To spray, identify the pathogen, then use appropriate chemical (copper for bacteria, sulfur for fungi). As always, follow label directions.
Disease risk is also impacted by weather. Downy mildew happen with hot humid weather. Apple scab happens with cool wet springs. Use weather to know what might be coming. Know that when there’s going to be fog and rain predicted, pay extra attention to your garden. Wet weather is a perfect growing environment for late blight. A tomato crop can be lost fastly. Knowing the risk puts you ahead.
Balance is the key. A balanced garden is a healthy garden. It resists disease. It reduces stress in its members. It keeps things clean and dry, that’s a barrier to threats. You do not need any expertise. Just pay attention to what happens in your own garden. Prevention is better than cure. A thriving garden, not a sterile garden, is what you want. Begin by thinking about good spacing and soil based off soil quality.