Tree Topics

Aphids: Small in Size, Many in Number

Posted on June 26, 2019 by Bartlett Tree Experts

Aphids are small, sap-sucking insects. Some of them feed on more than one type of plant— for example, apple grass aphids feed on young new leaves and blossoms of apples until the beginning of summer when they migrate to oats, grasses and reeds for the rest of the season. Others feed on just one food source, like the lime leaf aphid, which feeds only on limes. Many different species exist, impacting a huge range of broad-leaf trees and shrubs.

Aphids reproduce asexually and their populations can grow quickly to an unmanageable size.

Posted in Pests and Diseases

Oystershell Scale: An Unusual Insect Pest

Posted on June 25, 2019 by Bartlett Tree Experts

Oystershell scale (Lepidosaphes ulmi) belongs to a group of insects called the armored scales. The “armor,” is produced by a waxy secretion combined with the insect’s own body cast during each molt. This protective outer layer helps shield the oystershell scale from natural predators.

Oystershell scale

Posted in Pests and Diseases

Decline in Spruce Trees

Posted on June 24, 2019 by Bartlett Tree Experts

Over the past decade, spruce trees have suffered an abundance of issues. All species of spruce, including Colorado blue and white spruce, are being affected, but particularly concerning is the prevalence of ‘decline’ symptoms on well-established Norway spruce. Originally a favorite due to the relatively low incidence of health issues, the Norway spruce is now experiencing serious health concerns. Environmental factors such as drought stress, elevated summer temperatures, and wetter growing seasons have played a significant role in twig dieback and needle defoliation.

norway spruce experiencing serious health concerns

Norway spruce are now experiencing serious health concerns.

Posted in Environmental Issues, Pests and Diseases

Ivy on Trees is a Concern

Posted on June 20, 2019 by Bartlett Tree Experts

Although long used as a groundcover, ivy is harmful for trees. It is not indigenous, and many species are aggressively invasive and displace native species. In North America, the most common culprits are English ivy (Hedera helix) and Irish, or Atlantic, ivy (Hedera hibernica). Tree health and safety are the major concerns regarding ivy for arborists.

Ivy can reduce tree stability and lead to failure for a number of reasons. Structural or flare roots are one of the most important areas of a tree to inspect. If this area is obscured by ivy, the arborist cannot conduct a proper risk assessment of the tree, and critical information about tree stability cannot be determined. Another concern is that ivy adds considerable weight and wind resistance in a tree canopy. Because ivy is evergreen, trees that would normally be bare during winter suffer extra stress from rain and wind.

Ivy can add considerable weight and wind resistance in the canopy.

Posted in Environmental Issues, Tree Advice

What Causes Girdling Roots?

Posted on June 19, 2019 by Bartlett Tree Experts

Incorrect planting can lead to the production of girdling roots below the soil grade. Girdling roots are lateral roots that emerge at or slightly below the soil surface and cut into at least one side of the main trunk. A girdled trunk/stem will weaken a tree, and significantly reduce its lifespan because of a predisposition to diseases, insects and wind throw. Girdling roots can form when root collars are buried, or when a tree from a nursery is planted with pot-bound, circling roots. A pot-bound root will continue to circle the trunk, eventually resulting in a girdling root as the root grows in diameter.

Posted in Tree Advice, Tree Research, Tree Safety