Addition of organic matter: Regardless of whether the pathogen is present in the soil or not, the addition of appropriate quantities of organic matter in the form of mulches, manures, and composted materials to and on the soil is beneficial if appropriate to the plant species. Composts and mulch will increase the levels of soil microorganisms (soil foodweb), such as beneficial fungi (e.g. Trichoderma) and beneficial bacteria. This increase in the complexity of the soil foodweb will suppress the activity of pathogens and retard disease development.

Provide Optimal Environmental Conditions: A healthy actively growing plant can better resist the incursions of the pathogen. Proper nutrients, water, temperature, light, drainage, etc. can be provided and manipulated to promote plant health.

Planting practices: Promoting root growth may help compensate for damage to the root system from Armillaria. Plant in holes wide enough to promote rapid root growth. Combined with good nutrition, good root growth may allow the plant to compensate for damage caused by pathogens.

Good drainage: Ensure that drainage is adequate to prevent water logging, which promotes the incidence of disease and it's severity. Proper planting methods should minimize drainage problems. The installation of a subsurface drainage system prior to planting can be considered for sites with poor drainage.

Plant material: Do not plant material that is pot bound, diseased or deformed. It will be more susceptible to disease. Never attempt to propagate diseased or even marginally healthy plant material.

Planting Situations and Irrigation Practices: In natural situations in Southern California Armillaria is rarely a fatal plant disease. Oaks have co-existed with Armillaria for centuries, as long as they are not irrigated during the summer when Armillaria is most active. Improper or ill-advised irrigation practices and grade changes in managed landscapes can lead to conditions that promote the spread of Armillaria and result in plant loss. Planting and watering underneath a California live oak and/or raising the grade in the root zone just a few inches can be enough to cause the tree to decline and may shorten its life significantly.

Sanitation And Reduction Of Inoculum: Sanitation of tools, machinery and even boots is a very effective way of limiting the spread of many plant diseases. Although Armillaria does spread and infect new areas by the underground growth of rhizomorphs (root-like structures), cleaning tools and equipment before working in a new area or with a different plant can decrease the chance of infection.

Isolate infected plants: Never move a plant from an infected site to an uninfected site. If the species is required in these circumstances, make propagations as appropriate to the species. Site preparation, the addition of organic matter, and good drainage are essential when replanting any material. Proper planting procedures and cultural care after planting are especially important when Armillaria management is a concern. When removing an Armillaria infected plant, it is essential to remove as much of it, including roots, as possible. The pathogen may persist in living and dead tissue for many years.

Summary of Armillaria Prevention Practices:

·	Keep the root crowns of oaks and other susceptible plants dry. Adjust irrigation emitters so they face away from the trunk.
·	Manage irrigation so that the soil has a wet/dry cycle, not even ferns like to be kept at saturation point continuously.
·	Plants that are suffering from cultural or environmental stress are more prone to Armillaria infestation.
·	A complex soil food web offers the maximum resistance to soil diseases such as Armillaria. Cultural practices that enhance the soil foodweb bio-diversity help create natural disease suppressant qualities in the soil.