Our Changing Spring
Many trees began leaf growth earlier than ever before in response to record-breaking warm temperatures in mid-March. Recent frost events that have followed the early warmth can damage or even kill the new leaves on trees.
A healthy tree can grow a new set of leaves when needed, but it can be a source of stress to the tree. The growth of the first set of leaves is a heavy draw on stored energy, leaving reserves at their lowest point for the year. Building a second set of leaves costs the tree energy it would have otherwise used for growth or defense against attack from disease or pests.
Trees affected by frost injury will show the small, new leaves turning shriveled and discolored. They might fall off or remain on the tree. Most evergreen species have not started to develop needles yet, so they may have escaped injury for now.
Fruit trees may have reduced crops of fruit this year if their flowers have sustained damage.
It will take time to see the results of the changes in our weather. New leaf growth often takes several weeks to start development. Each type of tree will react differently, and each section of the Metro area will be affected differently.
If you are concerned about how frost injury may be affecting your trees, arrange for your Rainbow Consulting Arborist to visit your property. Your Arborist can assess the situation and make recommendations to support the health of your trees, such as watering and fertilization.
Fertilization can be helpful for stressed trees, but beware of applying doses of fertilizer that force rapid growth. These can further deplete the limited energy reserves of the tree. Our formulas are designed to provide what the trees need for proper response to stress with slow released nutrients.
Don’t forget that we are still in a drought. If your soil is dry, irrigate the root zone of your trees until the soil is moist down to a foot below the surface. A soaker hose works well for this task, as the water is delivered slowly and will not run off before the soil absorbs it. Soaker hoses put the water at the ground level where it is needed, and leaves the upper part of the tree dry. Avoid irrigation methods that get the needles or leaves wet, as this creates ideal conditions for infection by fungal diseases.
Kent Honl
Board-Certified Master Arborist MN-0158B
Rainbow Treecare
