Welcome to the world of tree care! In the left hand column of the image below, you will find links to the many maintenance duties you can do to help keep your landscape trees healthy and safe. The accompanying chart highlights the most favorable timing for the listed tree care activities. Below this chart you can find links to other complete chart versions that are larger and easier to read.
Inspect your landscape trees and shrubs often- especially after storms. After storms, hazard trees with loosely hanging branches or split trunks need to be removed as soon as possible to avoid any damage to buildings, people, and to other trees or shrubs.
At other times of the year keep a watchful eye for developing decay in trunks and roots, broken and hanging branches, dead branches or trees, an abnormally leaning tree, or anything that may indicate that a tree or part of it could fail and cause damage or injury.
Keep a watchful eye for problems that may be developing on the plants in your landscape. Timely prevention is always more effective and economical than reacting to problems once they have developed. Certain samples can be sent to your local Plant Disease Clinic (.pdf) for diagnosis.
The stems of landscape trees and shrubs may need protection from animals or mechanical equipment, especially during the winter months. Animal damage (feeding or rubbing) can be avoided by placing wire mesh or hardware cloth at least 3” from the stem. Mechanical damage (e.g. lawn mower or weed whip abrasion) can be avoided when a mulch ring (see mulch) or a plastic guard is in place. The plastic guard should only encase the portion of the lower stem that is most likely to be damaged by lawn equipment. As the tree grows the plastic guard will need to be removed and replaced in order to prevent girdling or stem constriction.
The recommendations in this chart refer only to nitrogen applications. Before fertilizing your landscape with a complete fertilizer (nitrogen-phosphorus-potassium), contact a soil testing laboratory for a basic soil test [For MN only: U of MN Soil Testing Labratory]. A basic soil test will provide you with readings on organic matter, pH, cation exchange capacity, macronutrients and micronutrients (Smiley, 2003). Soil testing laboratories may offer timing and quantity recommendations for complete fertilizers (N-P-K).
Staking and guying of trees is rarely needed and is only necessary when the tree will not stand up on its own. These practices may be necessary for 1-3 years while roots are growing and beginning to stabilize the tree. Check attachment points on the stem every 3 to 6 months, loosen if necessary and remove within one year of placement.
How to prune trees is an excellent publication designed to illustrate the types of pruning that can be done, how pruning cuts are made, when to prune different plants, and more.
Waiting until the plant is dormant is the safest time to do any live-branch pruning. However, unless the tree or shrub is susceptible to infectious disease (e.g., oak wilt, fire blight), removal of weak, diseased, crossing, rubbing, or dead limbs can be done throughout the year if needed.
Evergreen shrub shearing is a practice that can be used to maintain a geometric and formal shape of the plant. It is important to note, however, that once a shape has been formed yearly maintenance is required to preserve the design.
Removal of weak, diseased, or broken branches, along with double leaders or dead evergreen branches can be done at any time with little consequence to tree health. “Conifers may be pruned any time of year, but pruning during the dormant season may minimize sap and resin flow from cut branches” (Bedker et al., 1996).
Mulching with organic mulches (e.g. leaves, needles, hardwood and softwood bark and wood, grass, cocoa hulls, straw, etc.) helps to maintain tree health by aiding in water retention, inhibiting weed development, protecting from lawn mowing equipment, offering a layer of insulation during cold weather and adding organic matter into the soil (Carlson, 2003). At planting or transplanting time add a mulch layer 2-4″ deep around the tree as wide as you can tolerate but, to avoid stem damage, not against the trunk. Mature trees can be mulched at any time.