Seasonal Care for Trees and Shrubs
in Northern U.S. Climates

Bud swell

Bud swell occurs when the leaves under the bud are beginning to expand.  

Deciduous

Trees and shrubs that loose their needles or leaves every fall.  

Drip-line

In order to find a trees dripline, visualize the area on the ground that is directly below all the tree or shrub branches. At minimum, water this area, but don't water directly against the stem.  Depending on the situation the tree was planted in, roughly 50% of the trees roots are in the dripline.  

Established Tree

Established plants have been in the same ground location and have had a stable growing situation (e.g. adaquate water) for usually at least 5 years. These plants' root systems have extended well beyone their original planting location.

Trees and shrubs that do not loose their needles or leaves in winter and retain them for more than one growing season. Most evergreens do not require pruning except to shear into desired shape and form, control height, and to increase the density of branching.

Hazardous trees

A hazardous tree is defined as a tree with any portion that is structually weak or diseased and that tree or portion of that tree is likely to fail (e.g.break off, blow over, or fall) AND cause damage to targets such as a house, garage, other building, car, recreation equipment, humans, etc.

Defective tree + Target + Likelihood for damage = Hazard Tree

ISA Certified Arborist

Professional arborists who have a minimum of three years experience in some aspect of tree care and have passed an exam developed by an international panel of experts. These individuals must have an acceptable level of knowledge in all areas of arboriculture.

Leafed out

Trees are fully "leafed out" when leaves are fully expanded on all living and healthy branches.  

Monitor health

Regular inspection of the plant to identify signs and symptoms of poor tree health. For example, leaves damaged by insects or yellow leaves caused by soil nutrient deficiency.

Monitor safety

Regular inspection to determine if branches, trunks, or roots are structurally weak in order to avoid storm injury or injury to humans or structures.  

A time when leaves have naturally separated from the trees' branches due to seasonal temperature changes, day length and internal signals so that the tree is prepared for its period of dormancy (winter).  

Pine "candle"

Candles are young, new growth of pine shoots that appear candle-like at the end of branches. In spring, the candles are tender and can be snapped with fingers, which can help in size reduction and form.  

Plant Health Care (PHC)

A comprehensize management plan that includes arboricultural techniques that maintain the health, structure, and aesthetics of trees, shrubs, and herbaceous plants.  

The act of putting a young tree or shrub that is either bare root, B&B, containerized, or container grown in the ground to grow. 

Pruning

Removal of unwanted branches that are crossing, rubbing, diseased, or dead so that tree health, form, and safety is improved.  

Sign

The presence of an insect pest or pathogen or its parts or products seen on a host plant e.g., insect found chewing on the leaves.

Staking

The act of providing temporary support with stakes and attachments to stabilize newly planted/transplanted trees. Care should be taken to avoid staking it too rigidly so there is no tree movement or allowing attachments to damage the bark. Natural movement promotes root and trunk growth.  

Symptom

The reaction of a plant as a result of a disease or disorder e.g., leaves turning brown in summer.

Transplanting is defined as the digging of a plant from one location with the intent of moving it to a new location. For example, the plant is uprooted from a yard location, replanted and put into a new soil situation within the yard. Typically, during this process ~90% of roots may be lost.