Control of Pythium root rot in greenhouse production typically involves preventive fungicide applications that are costly, may run off to the environment, and are sometimes ineffective due to pesticide resistance. Adding silicon (Si) to the fertilizer regime has improved the Pythium response of several greenhouse vegetable crops. Anecdotal evidence suggests that Si may also improve the Pythium response of floriculture crops, but no research trials have been conducted. In this project we wanted to determine if silicon can reduce Pythium infection of snapdragons and New Guinea Impatiens.