The anxiety of seeing a cherry tree fail to leaf out or appear brown and brittle is common, but these visual symptoms do not always confirm death. A tree may simply be experiencing severe stress or late dormancy, depending on the season and local climate conditions. Before making the final decision to remove a cherry tree, it is important to perform a few simple diagnostic checks to determine if any living tissue remains. These viability tests provide a more accurate assessment of the tree’s internal health.
Conducting Viability Tests
The scratch test checks the condition of the cambium layer beneath the bark. Using a clean fingernail or a small knife, gently scrape a tiny patch of the outer bark from a twig or branch. If the tissue immediately under the thin outer layer is bright green and slightly moist, the section is alive and actively transporting water and nutrients. Conversely, if the tissue revealed is brown, dry, and brittle, that portion of the tree is dead.
Repeat the scratch test on several branches, moving progressively closer to the main trunk, since only a portion of the tree may have died back. Another check is the bud test, examining the terminal buds on the branches. Healthy buds should appear plump, firm, and smooth, indicating they are prepared to swell and open. If the buds are shriveled, brittle, or fall off easily when touched, it suggests a lack of hydration and nutrient flow, which is a strong indicator of dead wood.
The branch flexibility test offers a quick assessment of moisture content in the wood, especially on younger, pencil-sized growth. Gently bend a small branch; a live, healthy branch will be supple and flexible, resisting the bend. A dead branch, devoid of moisture, will snap like a dry twig. If all tests consistently show brown tissue, dry buds, and brittle wood across the entire canopy and down the main trunk, it confirms that the cherry tree is no longer viable.
Common Reasons for Decline and Fatal Damage
If the viability tests confirm widespread dieback, the cause is often an underlying fungal infection or pest infestation. One common cause of cherry tree decline is Cytospora Canker, signaled by gummosis. This appears as oozing of gummy sap from sunken lesions on the trunk and branches. Underneath these cankers, the tissue between the wood and bark is dead and dark brown.
Gummosis can also result from a severe infestation of borers, such as the Peachtree borer or Shothole borer, which tunnel into the wood and interrupt the flow of sap. Peachtree borer activity is often visible as gum mixed with frass near the base of the trunk. Shothole borers create numerous small, round exit holes on the branches, which may also ooze sap as the tree attempts to seal the wounds. These larvae effectively girdle the tree, causing rapid wilting and branch death above the point of infestation.
Root rot, particularly Phytophthora or Armillaria, thrives in poorly drained or waterlogged soils. Above-ground symptoms include yellowing leaves, wilting, and branch dieback that may affect only one side of the canopy initially. If the tree is suffering from root rot, the cambium layer near the soil line, when scraped, will often show a dark, brownish discoloration instead of healthy green. Environmental stress, such as extreme drought or severe winter damage, frequently weakens a tree enough to allow these opportunistic diseases and pests to take hold and cause fatal damage.
Action Plan: Treatment or Removal
If the viability tests indicate that a significant portion of the cherry tree is still alive, immediate intervention is possible. The first step is to prune out all confirmed dead, diseased, or insect-infested wood, making cuts several inches below the visible canker or damage line. It is imperative to sterilize all pruning equipment with a bleach or alcohol solution between cuts to prevent the spread of fungal spores to healthy wood.
Improving air circulation through thinning and ensuring proper soil moisture are the most effective treatments. Water the tree deeply during dry periods, but be careful not to overwater, as this can exacerbate root rot problems. If the tree is confirmed to be entirely dead, or if the remaining live portion is too small to recover a healthy structure (less than 50% of the main trunk), removal is the safest course of action.
A dead tree, especially a large one, can pose a significant safety hazard, and professional removal is often required to prevent accidental damage to property. It is important to remove all of the old root material and any sawdust from stump grinding. If a disease or pest infestation caused the death, avoid planting another cherry tree in that exact spot, or choose a disease-resistant variety, as the pathogen may remain in the soil. Amending the soil with topsoil and compost can help replenish the nutrients depleted by the previous tree and provide a healthier start for a new planting.