Play narration:

DISEASE CONTROL - CULTURAL CONTROL

AVOID CONDUCIVE ENVIRONMENTAL CONDITIONS

Recall that a favorable environment is one of the three sides of the disease triangle. Eliminating a favorable environment can eliminate or dramatically reduce disease. Once again, you may not feel that you have much control over environmental conditions. However there are several, easy techniques that you can use to modify the environment in your garden so that it is less favorable for disease development.

MODERATE SOIL MOISTURE

Perhaps the most common disease problem seen in the Plant Disease Diagnostics Clinic is that of root rot. While you can't stop the rain from coming, you do have control over how often and how much you water during dry periods. DON'T OVER-WATER. Provide enough moisture to prevent your plants from experiencing water stress, by don't continue to water once plants have received what they need. In addition, be careful not to over-mulch. Mulch tends to help retain water and a layer greater than three inches thick is not needed or recommended, and can be detrimental.

REDUCE HUMIDITY

Infection by many plant pathogens is favored during periods of high humidity, which in turn leads to extended periods when leaves are wet. The longer the leaf wetness period, the more likely infection will occur. Moderation of soil moisture is one way of reducing humidity. Less water in the soil means less water evaporating and contributing to air humidity. Also, don't plant ornamentals too close together. Crowded plants tend to reduce air movement, which in turn tends to lead to higher humidity and longer periods of leaf wetness.

FERTILIZE PLANTS PROPERLY

Balanced nutrition can have a big impact on plant health. Plants with nutrient deficiencies tend to be more susceptible to infection than those with a proper nutrient balance. On the other hand, be careful not to over-fertilize, particularly with nitrogen. Plants with excess nitrogen tend to produce fast-growing, succulent growth, and this tissue can be more susceptible to infection by some pathogens.

PREVENT WATER/HEAT STRESS

As with nutrient stresses, water and heat stresses tend to predispose plants to infection and/or more rapid disease development after infection.

BE AWARE OF ACTIVITIES SURROUNDING YOUR PLANTS

Be aware of any potential sources of pesticides or environmental pollutants that might adversely affect your plants. Take action to minimize the impact of these factors.