Being a garden scientist means that you use your eyes to observe and curiosity to notice changes. Healthy plants grow strong, while sick plants may show warning signs or symptoms. Similar to as if you have a cold, you might give a warning sign of sneezing. Plant diseases may be caused by fungus, bacteria or viruses.

This guide will teach you how to spot sick plants, what to do when you find a sick plant and how to prevent future sick plants. Grab your magnifying glass, put on your explorer eyes and let’s start our adventure in the garden!

What Do Healthy Plants Look Like?

Healthy plants usually:

• Have bright, green leaves
• Stand upright and sturdy
• Grow evenly
• Have smooth leaves without spots or holes
• Have an overall appearance that looks strong and happy, though a few holes or spots may be normal
• Produce flowers and vegetables at the right time

What Do Sick, Diseased Plants Look Like?

Diseased plants may:

• Have spots on leaves (black, brown or yellow)
• Turn yellow, brown, or wilted
• Look droopy, even when the soil is moist
• Have fuzzy, dusty or moldy growth
• Show strange patterns, like stripes or mottled colors

Brown leaves:

Photo by LSU AgCenter

Yellowing leaves:

Photo by LSU AgCenter

Spots on plant:

Photo by LSU AgCenter

Diseased plants typically get worse over time, especially if the weather is warm and wet. That is one reason why scouting your garden weekly is important.

Where Do We Find the Problems?

Check the entire plant for symptoms. This includes:

• The top and bottom sides of leaves
• Dark spots, cracks and soft areas on stems
• Rotting, spots or irregular shapes of flowers and fruits
• Signs on old leaves where disease typically starts first

What Might Have Caused the Problem?

Plant diseases often happen when the diseases have the right conditions to grow. Some common causes include:

• Too much moisture (rain, humidity, water on leaves, wet soil)
• Crowded plants with little airflow
• Warm weather
• Dirty tools or hands spreading the disease
• Sick plants left in the garden, allowing the disease to spread

Garden scientists may not be able to stop the problem, but we can try to prevent future problems.

What Can We Do To Help?

• Remove the badly sick leaves (or entire plants if needed) and tell an adult
• Water near the soil, not on the leaves
• Space the plants farther apart so that air can move between them
• Wash hands and tools
• Look at plants every week

Conclusion

These good garden scientist habits are sure to help prevent the spread of more disease. Good garden scientists do not need to know the name of every disease, but they need to look carefully, ask questions and share what they see.