Potted plants generally include bedding plants, perennials, and flowering and foliage plants. Two main strategies dominate potted plant production: growing a variety of flowering crops weekly (e.g. kalanchoe, begonia, miniature roses) or focusing production on seasonal plants (e.g. poinsettia, spring-flowering plants). High quality floriculture crops require an abundant supply of water for irrigation, which should be checked for pH, salinity, EC, mineral content and any possible contaminants. Most soil-grown ornamental production uses open irrigation systems with subsurface drains beneath the greenhouse. Flowering plants must be sold before the peak of their flowering period, but timing is not as critical for foliage plants. Pest infestations in potted plant operations can result in hundreds of thousands of dollars in losses as a result of crop damages as well as trade restrictions aiming to prevent pest propagation.