University of Maryland Extension

Cultural and Environmental

Diagnosing a plant problem when there are no apparent biotic (disease pathogen or pest) causes can present a real challenge. An abiotic plant problem is not caused by any disease organisms or insects. An accurate diagnosis, whether biotic or abiotic, involves both science, (botany, entomology, and pathology) and art (strategy, investigation, and decision-making). Abiotic problems can be very difficult to diagnose because they include site conditions, weather, and cultural practices. Below are some common abiotic or environmental problems of trees and shrubs. Click on the title underneath the photo for more information.

A large percentage of plant problems are primarily caused by abiotic factors. Symptoms can mimic disease and insect problems, leading homeowners to the wrong conclusion about the cause of the problem.

air pollution damage on leafletAir Pollution Damage

algae on trunk
Algae, Lichens, and Mosses

Thinning boxwood
Boxwood Decline

large growth on tree trunk
Burls

brown leaf margins
Chlorine Toxicity
compacted soil around base of tree
Compacted Soil
declining tree due to construction near tree
Construction Damage
damaged flowers
Damage to Flowers

drought symptoms
Drought 

early fall coloration street tree
Early Fall Coloration
 

wires embedded into trunk
Embedded Wires

excessive mulch around tree trunk
Excessive Mulch

no flowers
Failure to Flower
 
freeze injury azalea
Winter damage 
cracks in bark
Frost cracks,
sunscald, growth cracks
 

roots wrapped around trunk
Girdling Roots

excess soil around trunk
Grade Changes
 
bulging graft
Graft Failure & Normal Bulging
herbicide damage on holly
Herbicide Damage
lightning damage on trunk
Lightning Damage
 
yellowing of leaves due to low light
Low Light 
mechanical damage holly
Mechanical Injury 
declining tree
Natural Decline
 
damaged shrub
Natural Gas Injury
pine fall color
Normal Leaf Shedding
nutrient deficiency rhodie
Nutrient Deficiency

phyto ap leaf
Phytotoxicity

tree planted too deeplyPlanted Too Deeply 

 declining tree due to neglectPoor Plant Care

tree not establishing
Poor Plant Material

salt damage
Salt/Fertilizer Damage

severed roots near sidewalkDamaged Roots
wet spot on trunk of tree
Slime Flux (Wet Wood)
snow boxwood
Storm Damage

surface tree roots
Surface Roots
damaged plants from toxic mulch
Toxic (sour) Mulch

walnut wilt juglone
Walnut Wilt (Juglone)

excessive water
Water, excessive
  

sprouts growing from tree
Water Sprouts

stressed azalea
Site Problems

 

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