Phytophthora ramorum

Frequently Asked Questions

What plants are at risk?

As of August 2013, 46 plant species have been proven hosts and another 71 plants have been associated with the disease. Some of these species can be grown in Illinois and include:

• Japanese pieris,
• Douglas fir,
• rhododendron,
• witchhazel,
• viburnum,
• beech,
• and lilac.

The official P. ramorum US host list is provided by USDA APHIS (Adobe PDF). Keep in mind that the list changes often, so note the revision date on any such listing.