Hello Susan,

This appears to be Gummosis,
Here’s the good news first: gummosis in a sand cherry does not contaminate soil or harm nearby plants. Whatever is happening to your sand cherry is tree‑specific, not something that spreads through the soil to peonies, fruit trees, or ornamentals. The sap drip that damaged your peony leaf is mechanical/chemical injury from sticky resin, not a sign of infection. Cherry sap can be acidic and can “burn” soft herbaceous leaves, but it does not transmit disease.

Key point: Gummosis is a symptom, not a disease — treat the underlying cause early to prevent canker spread, branch dieback, and tree decline

Key takeaway: Gummosis in Michigan stone fruit is best managed through early detection, sanitation, careful pruning, and weather-based timing, with MSU IPM tools supporting decision-making

RESOURCES:

Gummosis of Fruit Trees

Gummosis (Cytospora/Perennial Canker) | USU

StoneFruitIPM_Bacterialcanker7.pdf

Below is a Michigan‑specific breakdown of what’s happening and how to safely remove the tree.

What’s causing gummosis on sand cherry?

Sand cherries (Prunus × cistena and related hybrids) are not long‑lived trees in Michigan. They commonly decline after 10–15 years due to:

1. Cytospora canker (very common on Prunus)

Amber or dark gum oozing from cracks or wounds

Branch dieback

Sunken or cracked bark

Often starts after winter injury or drought stress

2. Borers (less common but possible)

Gum mixed with sawdust (“frass”)

Entry holes at the base or lower trunk

3. Environmental stress

Freeze–thaw injury

Drought

Trunk wounds

Old age (sand cherries decline early)

All three cause gummosis, and once a sand cherry is oozing heavily and declining, there is no curative treatment. Pruning out cankers can help early on, but advanced decline means the tree is nearing the end of its lifespan.

Do you need to worry about the soil or nearby plants?

No.

Cytospora, borers, and stress‑related gummosis:

Do not persist in soil

Do not infect peonies, perennials, shrubs, or non‑Prunus trees

Do not spread through root contact

Do not contaminate mulch or compost

The only plants that can be affected are other Prunus species (cherry, plum, peach, apricot). Even then, infection requires wounds, not contact with soil.

Your peony leaf damage is simply from sticky resin sitting on the leaf, not disease transmission.

What’s the best way to dispose of the sand cherry?

1. Cut the tree down at the base

You can leave the stump or grind it—either is fine. Cytospora does not spread through soil.

2. Remove visibly infected branches

Place them in:

Municipal yard waste, or

Burn pile (if allowed in your township)

Do not compost infected wood at home.

3. Leave roots in the ground

They will naturally decompose and will not harm future plantings.

4. Replace with a non‑Prunus shrub

If you want to avoid future gummosis issues, choose:

Serviceberry

Viburnum

Ninebark

Dogwood

Lilac

Hydrangea

All are safe and long‑lived in Michigan.

Protecting nearby plants

You don’t need to treat the soil or surrounding plants.

Just:

Rinse any sap off nearby leaves

Mulch the area after removal

Avoid wounding other Prunus trees during wet weather (Cytospora enters through wounds)

If you want a precise diagnosis, you need to send a sample of a branch with the gummosis. Along with your images

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