I neglected to mention above, there is a red delicious apple tree nearby and I believe it needs the impacted tree for pollination. Production has decreased on that tree as well (maybe it needs better pollination?) but it does not have any black areas on it. If the answer is cut the sick tree down completely, can I plant a new apple tree in its place?

Hello Jennifer,

It’s very likely that your Golden Delicious apple tree has developed a trunk canker, most commonly caused by black rot or another canker‑forming pathogen. Once these diseases enter the wood, they cannot be cured with sprays, and advanced infections often require removing the tree.

Below is a clear, Michigan‑specific breakdown of what’s happening and what to do next.

What the Black Area on Your Apple Tree Likely Is

Based on your photo and symptoms:

Black rot (Diplodia seriata) is a common cause of spreading black, sunken, cracked bark on apple trunks and limbs.

It often begins after winter injury, which is very common in Michigan.

Once the fungus enters the wood, fungicides cannot stop it.

The disease slowly girdles the trunk, reducing water and nutrient flow—this explains your poor fruit production.

Can the Tree Be Saved?

If the canker is on the trunk (as in your photo):

You cannot treat it with sprays.

Pruning won’t help because you cannot cut out trunk infections without removing the trunk itself.

If the canker is large or spreading, the tree will continue to decline.

Conclusion: If the canker covers a significant portion of the trunk, removal is recommended.

Should You Cut It Back to the Lowest Branch?

You can try cutting the tree off well below the canker and letting it regrow from a water sprout, but:

Regrowth is not guaranteed.

It takes years to return to fruiting.

Most home growers find it more practical to remove and replant.

What About Your Red Delicious Tree?

Your Red Delicious does not need the Golden Delicious specifically, but it does need a compatible pollinator.

Golden Delicious is an excellent pollinizer, so losing it can reduce fruit set on the Red Delicious.

However, poor pollination can also come from:

Low bee activity (cold springs, rain, lack of pollinator habitat)

Mismatched bloom times

Stress on either tree

If You Remove the Sick Tree, Can You Replant in the Same Spot?

Yes. Apple replant disease is real, but manageable for home growers. Michigan Extension recommends:

Removing as much old root material as possible

Adding compost

Planting on a slight mound for drainage

Choosing a disease‑resistant variety

There is no issue with planting another apple tree where the infected one was, as long as you remove the diseased wood.

What You Should Do Next (Step‑by‑Step) IMPORTANT

1. Confirm my diagnosis - Because trunk cankers can have multiple causes, the most accurate step is to send a sample to the MSU Plant & Pest Diagnostics Lab. They routinely diagnose apple trunk diseases for Michigan growers. The lab will tell you if they need a sample

I recommend you email the MSU Plant & Pest Diagnostics Lab a photo of your Golden Delicious apple tree for confirmation of identification.

Their email is <personal data hidden> - Please include your first and last name.

The experts there can also provide you with the best treatment options.

The lab will let you know if they need a sample sent.

The lab may also ask for additional images. So be prepared.

Their website is at this link:

Plant & Pest Diagnostics (msu.edu)

Their Contact Information is at this link:

Contact Us - Plant & Pest Diagnostics (msu.edu)

This link will explain the details on submitting a sample to the MSU Plant & Pest Diagnostics Lab:

Submit Samples - Plant & Pest Diagnostics (msu.edu)

2. If confirmed as black rot or another trunk canker

Remove the tree entirely, or

Cut below the canker and attempt regrowth (low success rate)

3. Sanitize the area

Remove fallen leaves, mummified fruit, and dead wood

Do not leave infected wood on site

4. Replant with a compatible pollinator

If you remove the Golden Delicious, replace it with another mid‑season blooming apple variety to pollinate your Red Delicious.

Good options:

Gala

Fuji

Honeycrisp

Cortland

5. Improve pollination

Plant pollinator‑friendly flowers nearby

Avoid mowing or spraying during bloom

Consider adding a small mason bee house

Reference:

Diagnosing and Managing Fruit Tree Trunk Injuries

I hope this helps!