Pruning Deciduous Trees

Laura Jull, UW-Madison Horticulture, UW-Extension Revised:  8/13/2012 Item number:  XHT1014 Why prune trees? Pruning is important for a variety of reasons.  Pruning can help control the size of a tree, direct growth, influence flowering or fruiting, or maintain plant health and appearance.  Pruning can also increase the safety of a tree by removing broken, diseased, […]

Black Walnut Toxicity

Ann Joy and Brian Hudelson, UW-Madison Plant Pathology Revised:  5/7/2010 Item number:  XHT1017 What is black walnut toxicity? Black walnut trees (Juglans nigra) produce a toxic substance (called juglone) that prevents many plants from growing under or near them. Related trees like butternut (J. cinerea) and shagbark hickory (Carya ovata) also produce juglone, but in […]


Ken Frost* and Brian Hudelson, UW-Madison Plant Pathology Revised:  4/28/2012 Item number:  XHT1027 What are lichens?  Lichens are organisms that arise from mutually beneficial interactions between certain fungi and algae.  The fungi provide the physical structures of the lichens, as well as protection for the algae.  The algae, in turn, produce food for the fungi […]

The Basics of Micro Irrigation

Micro irrigation has numerous advantages over sprinkler irrigation and can be used in greenhouses, orchards, vineyards, fields, lawns, and gardens. Learn about the components that comprise a micro irrigation system along with the benefits (reduced water usage, reduced potential for foliar diseases, reduced energy costs, etc.) and drawbacks these lower pressure systems provide.

Homeowner Guide to Emerald Ash Borer Insecticide Treatments

Pest Alert Authors: PJ Liesch and R. Chris Williamson, UW Entomology Last Revised: 04/07/2022 X-number: XHT1181 Emerald ash borer insecticide treatment considerations.  Several insecticide products are available to homeowners for control of emerald ash borer (EAB).  Since the presence and infestation level of EAB is quite difficult to determine at early stages of an infestation, insecticide treatments may […]

Landscaping In Spite of Black Walnuts

Black walnut trees can have a dramatic, negative affect on certain plants. Black walnut trees, and a few other types of trees, produce a chemical called juglone that causes wilting, yellowing of leaves and sometimes the death of susceptible plants. To learn more about juglone toxicity and which plants are suceptible, read this article…

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