Pests and Diseases
Pests and diseases can make a mess of a well-maintained and beautiful garden. It’s essential to do everything you can to keep them under control. Use Penn State Extension’s extensive resources and learn about recommendations for managing garden pests and diseases, including webworms, beetles, weevils, mites, slugs, spotted lanternflies, leafminers, spiders, and aphids. Find tips on scale, root rot, viruses, and integrated pest management.
Common Garden Pests and Diseases
You might encounter a range of problems in your home garden, many of which will result from pests or diseases. Scouting your garden and recognizing the root cause of a problem means you’ll treat it more effectively.
If your cucurbits are wilting, it could be because of several diseases, including bacterial wilt, Fusarium wilt, and cucurbit yellow vine wilt. However, it could be abiotic stresses such as waterlogged soil.
The reason for there being no fruit on your trees could also be pests or diseases. On the other hand, it could be over-pruning or over-fertilization that is the cause.
Browning leaves and leaves with a pale green color in orchardgrass and timothy may indicate a fungal infection.
Pests and diseases can also affect the plants in your home. Houseplant damage can result from pests such as aphids, mealybugs, mites, scale, thrips, and whiteflies. Common diseases include anthracnose, leaf spots, and powdery mildew, as well as root and stem rots.
One insect pest that is now considered an invasive insect is the spotted lanternfly. Learn how to identify this pest, and you can help contain its spread.
Identifying Garden Pests and Diseases
There are lots of things that can make your plants unwell. Identifying the root cause and recognizing symptoms of different diseases means you’re able to make an informed treatment decision. If you want a low maintenance garden, aim to restrict your use of key plants, as these are the ones that frequently have diseases.
Common pests include:
- Bulb crops: Onion thrips, onion maggots.
- Leafy vegetables: Leafminers, aphids, cabbage worms.
- Sweet corn: Corn earworms, European corn borers, fall armyworm, sap beetles, flea beetles.
- Fruiting vegetables: Broad mites can cause severe damage to tomatoes and peppers.
- Tomatoes: The tobacco hornworm can devour sizeable portions of tomato plantings. Another problem for tomato growers is tomato-potato late blight.
- Strawberries: Anthracnose is caused by different species in the genus Colletotrichum
- Grapes: Powdery mildew symptoms include cupping of leaves, scorched or brown leaves, and white, powdery patches on the upper surface of the leaves.
- Apples and pears: Mucor rot is a fungal disease that is a problem in postharvest storage. Pears can also suffer from stony pit, which is a destructive virus that leaves the fruit looking unsightly and unmarketable.
- Potatoes: A common problem for potato growers is early blight.
- Trees and shrubs: A common disease with more than 75 species of trees and shrubs is fire blight.
Pesticides and Integrated Pest Management in the Home Garden
Traditionally, home gardeners would use pesticides to manage pests in their gardens and keep the landscape healthy. Commercial growers have used Integrated Pest Management for many years. More and more amateur and home gardeners are now using home, lawn, and garden integrated pest management techniques. It is a management method that seeks to limit or suppress pest populations by using various compatible tactics.
Integrated pest management tactics minimize potential harmful effects on the environment and human health. There is still a place for synthetic, natural, and organic pesticides, but generally, only as a last resort. A crucial part of IPM is scouting for common diseases, mite pests, and beneficials.
Preferred pest management tactics include encouraging beneficial insects into the garden, biological control, planting cover crops, and monitoring insect pests.
- Workshops
$15.00
Landscape Pest Walk
When Multiple Options AvailableLength 2 hoursJoin our workshop for Green Industry professionals to take your landscaping skills to the next level. Earn Pennsylvania pesticide credits while learning about identifying insects, diseases, safe use of pesticides, and weed management. - Videos
Do Insects Matter to People?
Length 4:21Insects are often considered pests, but many are beneficial, helpful, valuable, and even tasty. Learn more about how insects matter to people. - Articles
Steps to Controlling Insect Pests in the Garden
This article offers a step-by-step approach to controlling common garden insect pests using integrated pest management (IPM). - Articles
How to Create a Wildlife Barrier for a Spotted Lanternfly Sticky Band Trap
Many residents attempt to control spotted lanternflies by placing sticky bands on tree trunks. This method of trapping should never be used without a wildlife barrier. - Articles
Adapting to Invasive Jumping Worms
Jumping worms (Amynthas and Metaphire spp.) are invasive species that have a negative impact on our ecosystems. This article explores how gardeners might mitigate their detrimental effects. - Articles
Tips for a Bug-Free Houseplant Haven
Now that we spend more time indoors, we look at the plants that share our homes. How should we manage the insect pests that might be sharing the plants? - Webinars
Free
Managing Tree of Heaven and Other Invasive Trees
When Watch NowLength 1 hourRecorded Nov 17, 2023Learn to combat invasive species like Tree of Heaven at our workshop. Earn SAF and ISA credits while enhancing your skills. Perfect for forestry pros and anyone impacted by invasive trees. - Articles
Pyracantha Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Pyracantha diseases. - Articles
Viola Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Viola diseases. - Articles
Plum Pox Virus in Ornamentals
Plum pox is a serious disease of Prunus species caused by a virus. - Articles
Viburnum Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Viburnum diseases. - Articles
Boxwood Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Boxwood diseases. - Articles
Pieris Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Pieris diseases. - Articles
Ficus Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Ficus diseases. - Articles
Oak Leaf Blister
Oak leaf blister, caused by the fungus Taphrina caerulescens, occurs on most species of oaks. - Articles
Ash Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Ash diseases. - Articles
Gazania Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Gazania diseases. - Articles
Tulip Poplar Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Tulip Poplar diseases. - Articles
Easter Lily Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Easter Lily diseases. - Articles
Vinca Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Vinca diseases. - Articles
Kalenchoe Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Kalenchoe diseases. - Articles
Sycamore Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Sycamore diseases. - Articles
Verbena Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Verbena diseases. - Articles
Baptisia Diseases
Informational table showing disease name, symptoms, pathogen/cause, and management of Baptisia (False or Wild Indigo). - Articles
Key Plants and Key Diseases Outdoors
Selecting plants for placement in the landscape can be simplified if the key plants are known and if the key diseases on those plants can be identified.