Top 10 Diseases

Our treatments manage the most common tree diseases in Central Minnesota.

Apple Scab

An early season fungal disease that affects most crabapple trees in the landscape, particularly in the last few years. Only two preventative sprays are necessary for excellent control. The health of a chronically infected tree can suffer greatly from this easily controlled leaf disease.

TREATMENT: Spray Applications

Ash Anthracnose

A fungal disease that causes stunting, distortion and browning of emerging leaves. Spraying for control can be difficult due to the size of ash trees. Cultural practices like fertilization, mulching and proper pruning can counteract the effects of anthracnose.

TREATMENT: Spray Applications, Direct Injections

Cytospora Canker

A disease that attacks spruce from the bottom up, causing needle loss and branch death. Infected branches elude conspicious amounts of white resin. Removing infected limbs slows disease progression. There is no existing chemical control. Fertilization, mulch, and proper watering make a tree less
susceptible to the infection.


This fungal disease is common to stressed pines. The death of new shoots are an obvious symptom of infection. Recommendations vary depending on the
severity of infection, health of tree, and site condition.

TREATMENT: Spray Applications


Dosthistroma causes the discoloration and loss of needles to stressed pines, particularly red and Austrian pine. A commitment to treatment is necessary to achieve adequate control.

TREATMENT: Spray Applications

Dutch Elm Disease

The most devistating disease to date, killing nearly every elm tree in the midwest. Mature elms that remain need to be protected by injections paired with the
prompt removal of diseased limbs (sanitation).

TREATMENT: Injections

Fire Blight

A damaging bacterial disease affecting many plants, mostly mountain ash, hawthorn, and apples. Foliage and small branches turn brown to black and branch cankers appear sunken. The lone control method is pruning to remove diseased limbs and cankers during dormancy.

Oak Anthracnose

This leaf disease is mainly an aesthetic problem whose control is complicated by the size of the oak tree. Where the necessary spring sprays to control anthracnose aren’t feasible, mulching, fertilizing and proper pruning should be done to maintain the vitality of mature oaks.

TREATMENT: Spray Application or early spring Direct Injections

Oak Wilt

This disease is caused by a fungus that is lethal to all native oak trees. The symptoms, treatment options, and recommendations vary depending on the species and site conditions. In white and bur oaks, this disease can be difficult to diagnose.

TREATMENT: Direct Injection in spring


This fungal disease is often the cause of death for immature blue spruce. Control is difficult and requires a long-term commitment to a treatment program. Planting less succeptible native conifers reduces the impact of Rhizosphaera.

TREATMENT: Spray Applications