Signs of Trouble In Your Landscape

Insects, fungus, drought, heat, flooding – there are so many factors that can affect the health and beauty of your landscape. Signs of trouble can be obvious – like holes in leaves that have been chewed by insects, but other can be more subtle, like leaf mottling, or even confusing like determining if yellow leaves are from too much or too little water.

Of course, the best way to keep your landscaping healthy and looking great is to start off with the right plantings for your specific planting zone and landscape and soil type. Here are some helpful tips:

• Opt for Native – Native plantings are always a good place to start – they have proven to be able to adapt to our seasonal patterns which can include cold, snowy winters, hot humid summers and periods of drought and flooding.
• Understand your site location – Orientation (North, South, East, West) plus the amount of sun and shade your planting site receives are critical factors in your landscape success. For instance, while you may have an area that offers partial shade, if that spot is a western location that receives its sun time during the intense heat of late afternoon, it may be too much for plants that require partial shade.
• Know Your Soil Type – Heavy clay or easy-draining sand? Acid or alkaline? Knowing your soil’s pH level (you can get test kits from your Extension Office) and drainage can help you to determine which plants will thrive best as well as whether or not you need to amend the soil with nutrients and/or elements to help loosen/stabilize the soil for better drainage/moisture retention, respectively.

Even with the best location, soil health and plant selection, problems in the garden can still arise due to:

• Heat
• Drought
• Too much rain
• Humidity
• Insect infestation
• Disease
• Compacted soil
• Depleted soil nutrients
• Physical damage (kids, pets, wildlife, landscaping equipment)

Here’s are some signs to look out for in your yard which may indicate trouble:

Trees

• Changes in Leaves – Leaves that wilt, are brown, yellow and/or drop during the spring or summer are a solid indication of a problem. This can be anything from insects to fungal diseases, heat stress or even soil issues. Fruit trees like ornamental pear and plum trees are especially vulnerable to fungal diseases when the weather gets hot and humid.
• Falling Branches/Peeling Bark – While some trees like River Birch and Sycamores have naturally peeling bark, shedding bark is often a sign of fungal or pest infestation, as is falling branches.
• Fungal Growth on Tree Bark or Ground at Tree Base – Moss and lichen growth on trees is common and not typically indicative of a problem, but mushroom-like growths or fungi growing from the tree’s trunk can be an indication of dying wood. Mushroom or fungal growth in the ground at the tree’s base may be a sign of dying roots.
• Leaking Sap – This can occur when the tree has been physically damaged by landscape equipment, getting struck by an automobile or by lightening or as a result of boring insect infestation.
• Holes, Cavities and Bulging Growths – Holes in a tree’s trunk can be caused by numerous factors (insects, physical damage, etc.) and become attractive spots for pests. Conversely, a bulging growth can be indicative of a healing wound on the tree trunk, which may still house boring insects that can kill the tree and spread to other trees.
• Needle Cast – Foliar diseases in conifers where plants shed or cast off the needles. Needle cast usually begin at the base of the tree and slowly spreads up the tree, resulting in lower branch defoliation, caused by fungi.
• Tree Girdling – There is a layer just beneath the tree’s bark whose function is to transport water and nutrients throughout the tree. Heavy ties, wires, even drip irrigation put around the trunk of a tree can lead to girdling, which can inhibit the tree’s ability to absorb and distribute water and nutrients, eventually killing the tree. Additionally, if the tree was planted incorrectly, you may see root girdling, which looks like roots at the base of the tree that wrap around the trunk or crown of the tree.
• Poor Branch Structure – The long-term health and vitality of a tree can also be affected by its structure. Multiple trunks in larger trees can make them more prone to splitting from storm damage. Trees that are unbalanced from improper pruning (e.g., utility companies trimming branches to clear them from overhead power lines) or that lean are also more vulnerable to being uprooted from heavy rains and wind.

Lawns

• Discoloration – Urine spots from pets or wildlife, surfacing-feeding lawn insects, improper mowing (cutting grass too short), over-application of fertilizers or improper application of weed and pest control products can result in spots or larger areas of discoloration of your lawn. Additionally, drought and heat stress can cause discoloration.
• Fungal Diseases – Lawns are susceptible to variety of fungal diseases such as:
  • Black Spot: Black, sooty spots on leaf blades. Common during hot, humid conditions and after heavy rain.
  • Lawn Rust: Leaf blades turn yellow, maturing to orange, red or brown. Common in late summer/early fall after a dry period.
  • Dollar Spot: Small, sunken, circular brown spots (about the size of a silver dollar) common in spring and fall when days are hot and humid with heavy dew in the morning.
  • Brown Patch: As the name implies, brown patches throughout the lawn. Common in summer during times of high humidity.
  • Red Thread: Looks like red threads in the lawn. Common when turf growth has slowed, such as during times of cool temperatures, drought, or poor fertility and when conditions are humid.
  • Powdery Mildew: Looks like powder on the leaf blades, typically occurring in places not suitable for growing grass.
  • Anthracnose: Irregular shaped patches that start out reddish brown, then turn yellow, to tan to brown. Common during warmer temperatures and in lawns that have soil compaction and low nitrogen.
  • Lawn Thinning – This can occur from improper mowing, as well as insect infestation and lawn diseases.
  • Grass Easily Pulling Up/Looking Chewed – Grubs feed on the roots of the grass, so they can be difficult to see at first, but their damage will appear as grass that easily pulls up. You may also see the actual c-shaped grub beneath the grass that lifts up.

Shrubs and Perennials

Examples of problems in shrubs and perennials can include leaf yellowing, wilting, dieback, galls or blight and more. Symptoms shouldn’t be used alone to diagnose problems since they can be the result of multiple issues. For instance, wilting can occur due to drought, borer, canker, root rot, etc.

Additionally, symptoms on one part of the plant can appear due to damage on a different part of the plant. Leaf wilt can be caused by clearwing borers feeding on the stem, or Botryosphaeria canker.

The location of the damage on the plant, the type of damage, and the symptoms and signs are important clues in determining the correct diagnosis of the problem. Here is a list of common issues:

• Anthracnose: A group of fungal diseases that often start as leaf spots or fruit rots but may also move into petioles, twigs and branches, ultimately causing cankers or blighting.
• Blight: The progressive discoloration, dieback and death of plant parts. May include wilting and/or death of leaves, stems, flowers or entire plants. Blight may be a secondary symptom of stem canker or root rot. Causes include borer and stem girdling insects; fungal and bacterial pathogens; root rots.
• Blotch: Large and irregularly shaped spots or lesions, commonly due to fungal or bacterial disease.
• Bronzing: Copper or bronze color of leaves or needles caused by mites or pathogens.
• Browse Damage: Damage from deer, rabbits, squirrels, rodents, etc. feeding or nibbling on plants.
• Canker: A localized, cracked or sunken lesion on a branch, stem, or trunk resulting in blight or dieback caused by bacterial or fungal pathogens.
• Cracking: Poor pruning, string trimmer damage, or other injury coupled with weather extremes can cause the expansion of what might have been a minor injury. This may result from winter injury, previous physical injury and/or different growth rates in adjoining tissue.
• Defoliation: Loss of leaves due to insect infestation, pathogens, heat stress.
• Dieback: The gradual but progressive death of individual branches or shoots from tips toward the main stem. Often leading to decline. Causes include external injuries, fungal diseases, root rots, etc.
• Epinasty: An abnormal, downward-curving growth or movement of a leaf resulting from more rapid growth of cells on the upper side than on the lower side of the leaf stalk caused by herbicides or viruses.
• Gall: A swelling or outgrowth of plant tissue that can occur as a response to an injury, insects, or pathogens.
• Honeydew: The sticky, dew-like fluid released from the abdomen of insects like aphids and mealybugs.
• Leaf Scorch: Yellowing, browning and death of leaf tissue from the margin inward. Caused by drought, nutrient deficiencies, fungal and bacterial diseases.
• Leaf Spot: Localized destruction of the plant’s chlorophyll by the feeding of insects or pathogens including fungi, bacteria, nematodes, viruses, spider mites, lacebugs, thrips and more.
• Mosaic: Dark green, light green, and/or yellow areas forming a variegated pattern caused by a virus.
• Powdery Mildew: White, powdery spores of fungi visible to the naked eye.
• Ringspot: A target-like pattern of yellow, green or dead tissue commonly caused by viruses.
• Skeletonization: Feeding between the leaf veins by insects such as Japanese beetle or sawflies.
• Sooty Mold: Appears as a fine coating of soot on the leaf surface caused by fungi living in the “honeydew” of aphids or scale insects.
• Wilt: Loss of rigidity and drooping of plant parts caused by drought, insects, nematodes, pathogens (fungi and bacteria).