Monitoring the Garden

How to Identify Problems with Plants and What Conditions to Watch for

Many garden problems are difficult when widespread but easily “nipped in the bud” when caught early. Key to recognizing problems is knowing your plants. Walk the garden regularly and check on the plants when they are healthy so you can recognize change. Remember that some plants, such as coleus, are drama queens and wilt obviously when thirsty, so you know to water. Others, small pine trees for example, will die without wilting, so it is much harder to know they need watering.

Here are some conditions to watch for:


First the small new leaves droop, then bigger leaves. Wilting is usually due to the leaves not getting enough water. That can be because the plant needs water or that something has cut off circulation within the plant. Lots of diseases cut off circulation including fungal infections, viruses, and bacteria. Wilting can also be a symptom of too much water.


Leaves are yellow, not the green of the rest of the plant or other plants of the same variety. Again, it starts with a single leaf and then more do it. Yellowing signals a dying leaf or dying section of a leaf. In the fall, the plant has moved its chlorophyll into the roots for winter; this is healthy yellowing. Thirsty trees turn yellow in late summer, which is not healthy. Plants can show yellowing in response to too much water, too little water, and bacterial, viral, and fungal diseases.


Leaves are brown. Like yellowing, it starts with a single leaf and then more do it. The section that is brown is usually dead. Causes range from too little water to too much water, to too much sun, as well as bacterial, viral, and fungal diseases and damage from pests.

Spots on the Leaves

Irregular spots of any color, size or dimension—if you didn’t buy a spotted variety—are signs of a problem. It could be from insect damage or a disease. Too much light can cause leaves to scorch, which produces distorted yellow areas that become papery and brown.

Plants are tall and thin and tend to fall over. Often leaves are intensely green.

This is a result of not enough sunlight; the plants are growing tall trying to reach more light.

Pest Damage

Pests consume plants in a distinctive fashion. Deer and rabbits bite the tops off plants. Grasshoppers chew holes in the leaves, especially along the edges. Aphids appear as a group of small, usually green, insects clustered along the stem. Spider mites are tiny dots with a spiderweb-like filaments along the stalk. And so on. Different pests require different responses, from fences excluding deer to washing off spider mites with water or insecticidal soap.


First, not all damage requires intervention. Healthy plants can resist many types of damage. But if the plants look unhealthy, be sure to get an accurate diagnosis, for example from your local Cooperative Extension Office; the wrong treatment will likely make matters worse.


Here are some remedies

Not enough water: If the soil is dry down as far as you dig, there is too little water. Add water. Many plants will wilt a bit in the late afternoon, then recover in the evening. This is normal but suggests they could use light watering. DIY moisture check: Stick your finger into the soil near the base of the plant. If the soil is dry, this is a good indication the plant needs water.

Too much water: If the soil is soggy and wet to touch or to walk on, or stays like that for a substantial part of the day, there is likely too much water and the plant roots are drowning (they need air from tiny air pockets in the soil). Let potted plants dry out. Drain off the water outdoors or move the plant if the situation is likely to persist.

Too much sun (or light from grow lamps): Shade the plants or otherwise reduce the hours of direct sunlight.

Not enough sun: Move potted plants into brighter areas. Remove branches or other obstructions that shade the plants. If the conditions are likely to persist, transplant the perennials and don’t put those annuals in that spot next year.

Bacterial, viral, and fungal diseases: The best solution for these is prevention. Grow disease-resistant varieties, keep your garden tools very clean, and dispose of infected tissues immediately. Don’t compost a diseased plant.

Animal pests: Get expert advice in treating the specific pest. Remember that widespread insecticides will kill predators that are eating your pests, ladybugs that eat aphids for example, making control harder. Target just the pest, as specifically as possible, with natural and organic remedies.

Take it easy. Most plants grow fine without human intervention.