black walnut tree (126506 bytes)

Black Walnut Tree

line4.gif (1411 bytes)

By Robert Cox, Colorado State University Cooperative Extension, horticulture agent

While the black walnut tree is adapted to our area's soils and climate, you need to keep in mind a few things about this tree:

It grows large and eventually may provide too much shade for a small property. It's best not to think of black walnut as a landscape plant except on large properties. It really has few ornamental properties but does provide shade and nuts.

Walnut aphids are a regular insect pest.

Squirrels might become numerous and an annoyance.

All parts of walnut, including leaves, have an herbicide- like compound in them that inhibits growth of some other unrelated plants nearby, a sort of competitive advantage for the walnut. This phenomenon is called allelopathy.

The high value of walnut wood makes "walnut rustling" a problem where black walnut grows in forest stands or where it's planted as a timber crop. A few walnut-rustling cases have even been documented in urban areas where it was planted for the shade and nuts.

For more information, see Black Walnut Tree

Photo: Judy Sedbrook

Back to Trees

Back to Home

 

 

Ask a Colorado Master Gardener | Calendar | Children | Container GardeningCSU Fact Sheets
Credits | Diseases | FAQ | Flowers | Fruits | Gardening | GlossaryHouseplants | Insects & Pests
Lawn & Grasses | Links | New to Colorado | PHC/IPM | Soil | Shrubs | Trees
Vegetables | Water Gardening | Weeds | What's New | Who We Are | Xeriscape

Search

line4.gif (1411 bytes)

Contact Us | Disclaimer | Equal Opportunity

CSU/Denver County  Extension Master Gardener 2010
888 E. Iliff Avenue,  Denver, CO 80210
(720) 913-5278

E-Mail: denvermg@colostate.edu  

Date last revised: 01/05/2010