To avoid stress and poor development during propagation, it is important that the stock plants be maintained under optimal nutrition—prior to harvesting propagules. During propagation, nutrients are generally applied to seedlings and plugs by fertigation (soluble fertilizers added to irrigation water) or with controlled-release fertilizers that are either preincorporated into the propagation medium or broadcast (top-dressed) across the medium surface. Cuttings are normally fertilized with a controlledrelease fertilizer preincorporated into the propagation medium or with soluble fertilizer applied after roots are initiated. The development of intermittent mist revolutionized propagation, but the mist can severely leach cuttings of nutrients. This is a particular problem with cuttings of difficult-to-root species that have long propagation periods.
