See All Trees and Shrubs

Informational table showing disease name, symptoms, pathogen/cause, and management of azalea and rhododendron diseases.

Enhance your property with native trees and shrubs that support wildlife, improve water quality, and benefit local watershed projects.

Learn to manage landscape plant and turfgrass pests with expert instruction, pest identification, and horticultural best practices at this all-day workshop.

Penn State Extension Master Watershed Stewards to Host Seventh Annual Native Tree and Shrub Events to Promote Healthy Watersheds. Opens this July 2026!

Set your native trees and shrubs up for success with expert guidance on site selection, planting techniques, and post-planting care.

Recommendations for safe pesticide applications to control spotted lanternfly infestations.

Soil testing is a soil-management tool used to determine the fertility of soil as well as the optimum lime and fertilizer requirements for crops.

Pear psylla adults, Cacopsylla pyricola, look like small cicadas and become active any time the temperature is above 40°F.

Many things make plants unwell and pests and diseases are only two causes of poor plant growth.

Nematodes undoubtedly are the most numerous multicellular animals in the world. You can pick up a handful of soil almost anywhere and extract nematodes from it.

The pear leaf spot fungus, Mycosphaerella pyri, infects the leaves of pear, quince, and occasionally apple trees. Numerous leaf spots can produce defoliation.

Although it is not particularly common, pear scab is very destructive when it does occur.

Conduct a soil test, and lime and fertilize a 10-by-10-foot area where each tree will be planted.

The following general cultural controls will help to keep your trees healthy.

Cytospora canker, also known as perennial canker, peach canker, Valsa canker, and Leucostoma canker, can cause trees in young orchards to die. Infected trees in older orchards slowly decline.

Armillaria root rot, sometimes called shoestring root rot, is caused by various species of the fungus Armillaria.

The elongate hemlock scale, sometimes known as the fiorinia scale, is a serious armored scale insect pest on ornamental and forest hemlock trees in Pennsylvania.

The euonymus scale is a key pest of euonymus, pachysandra, and bittersweet. This armored scale insect is native to Japan and China.

The European pine sawfly is common in Pennsylvania. The larval stage feeds on the needles of pine trees in landscapes, nurseries, and Christmas tree plantations.

The fall webworm is a widely distributed native pest that appears from late summer through early fall. It feeds on many species of deciduous trees and shrubs.

The European pine shoot moth is a key pest of ornamental pine plantings, pines in production nurseries, and Christmas trees in Pennsylvania.

The black vine weevil is a serious pest in nurseries and established landscape plantings.

The boxelder bug frequently becomes a nuisance pest around homes and buildings near plantings of the boxelder, Acer negundo.

The boxwood leafminer is a serious pest of Pennsylvania plantings of boxwood, Buxus spp.

The boxwood psyllid is a common pest of boxwood, Buxus spp. It is not considered as destructive as other boxwood pests.