Renovating Minnesota’s

Streets and Landscapes

Introducing Genetic Diversity to the

Canopy

The Problem With Minnesota’s

Landscapes

Three Genera = 52.5% of All Trees

Maple 20.2% Ash 15.2% Spruce 18.1%

Maple Problems

Verticillium Wilt – a Vascular Disease

Stem Cankers – Fungal Infections of

Weakened Trees

Asian Long-Horned Beetle – Insect Pest that

Favors Maples

Deicing Salt – There’s no Tree More

Susceptible than Maple

Maple Problems

Ash Problems

Emerald Ash Borer

Ash Yellows

Verticillium Wilt

Ash/Lilac Clearwing Borer

Ash Problems

Spruce Problems

Rhizosphaera Needlecast

Cytospora Canker

Yellow-Headed Spruce Sawfly

White Pine Weevil

Spruce Problems

Can Anyone

Save our

Trees?

First of All, You Can Save Your Ash

Imidachloprid Soil Drenches

Tree-Age Trunk Injection

Tree Genetic Diversity

By Form (phenotype)

By “Species” (genotype)

A Genetically Diverse Landscape: 30:20:10

No more than 30% in same Family No more than 20% in same Genera No more than 10% in same Species

What does THAT mean?

Tree Genetics Diversity: What is

Good?

Elm Family

Rose Family

Birch Family

Pine Family

Olive Family

Family

Some Common Families

Elm Family Elm, Hackberry

Rose Family Crabapple,

Mountain-ash Birch Family Birch

Pine Family Pine, Spruce, Fir

Olive Family Ash, Lilac

Family Genera

Some Common Genera

Working in Diversity: Try These Trees

Trees for Streets

Trees for Parks

Trees for Lawns

Northern Pin Oak

‘Prairie Horizon’ Manchurian Alder

‘Dura Heat’ River Birch

‘Dakota Pinnacle’ Asian White Birch

‘Prairie Dream’ Paper Birch

Muscle Wood, Blue Beech, Hop-

Hornbeam

Ironwood, American Hornbeam

‘Northern Acclaim’ Honeylocust

‘Purple Robe’ Locust

‘American Sentry’ Linden

‘Frontyard’ Linden

‘Ivory Silk’ Japanese Tree Lilac

Balsam Fir

American Larch

White Pine

‘Snowcloud’ Serviceberry

‘Snowbird’ Hawthorn

‘Pink Spires’ Crabapple

‘Selkirk’ Crabapple

‘Mountain Frost’ Ussurian Pear

‘Prairie Gem’ Ussurian Pear

Showy Mountain-Ash

‘Prairie Sky’ Poplar

‘Prairie Cascade’ Willow

Getting These Trees

All Listed in Bailey Nurseries, Inc. catalog

Any Garden Center or Retail Nursery can

purchase them from Bailey Nurseries

Gary Johnson

Urban and Community Forestry

Department of Forest Resources

University of Minnesota

johns054@umn.edu; www.trees.umn.edu