
Tables from "Symptoms and management strategies for impatiens necrotic spot virus" by Mary Hausbeck,Plant Pathology in the March 3, 2006 edition of the Michigan State University Greenhouse Alert newsletter.
Current commercial horticultural information from the Cooperative Extension Office in Kent County Delaware, an outreach arm of the College of Agriculture and Natural Resources at the University of Delaware.
Pest problems in the landscape result from a horticultural ecosystem that is out of balance. This often is due to lack of diversity in a landscape that leads to pest buildup. Use of plants that have noted pest problems should be reduced. Practice those methods that encourage the buildup of competitors or natural controls of pests. If pest control is necessary, practice integrated pest management and consider all options before using a pesticide.
Encouraging beneficial or benign organisms in the landscape can go a long way to reduce or eliminate pest problems. Strive for a balanced ecosystem. Understand those practices that can encourage these "good" organisms above ground and below ground.
It is critical to use native plant species as much as possible. These are well adapted plants that are important for wildlife and will help to develop a horticultural ecosystem that will function well in our area.
In the end, consider whether you want to fight natural forces or learn to take advantage of them. Highly managed horticultural systems with limited diversity and high maintenance species are costly and often do not succeed in the long term. Think of how your short term actions will end up in long term consequences. In landscape design make sure your vision includes the creation of a successful and healthy horticultural ecosystem. Strive to understand the interactions that occur in the landscape to help you make better decisions.
I hope this series has been helpful with those of you interested in sustainable landscaping.
Gordon Johnson, Extension Horticultural Agent, UD, Kent County
Consider what effects structural components will have on the horticultural ecosystems and design to minimize negative effects. Limit root restrictions or design with rooting in mind (structural soils under walkways for example). Consider where water runoff will go and design to manage that runoff (rain gardens for example). Consider how structural components may increase radiation load, change light conditions, or limit plant space.
Consider how the landscape will be used by people and how this will effect the horticultural ecosystem. The goal is to blend man as part of the landscape.
Your management activities in the horticultural ecosystem can have major effects. Consider how you will manage the root environment. Plant nutrients and water can be limiting factors in a landscape; however, overuse of these inputs can have negative effects. Consider how your management affects light conditions, temperature, wind, humidity, and other microclimate effects.
Consider what the effects of the above management decisions would be on the horticultural ecosystem.
To be continued...
Gordon Johnson, Extension Horticulture Agent, UD, Kent County
Gordon Johnson, Extension Horticulture Agent, UD, Kent County.