Pro-Mix HP is a “High Porosity” professional growing medium designed for the cultivation of horticultural greenhouse plants. During the course of crop production, it is necessary to initiate a fertilizer program. The fertilizer program selected should consider water nutrient content, crop type and stage of plant development. It is essential to begin fertilization within 7 days after planting and maintain fertilizer applications throughout the course of crop production. To insure plants receive proper nutrition, it is advisable to periodically analyze fertilizer solution, nutrient content of growing media and plant tissue throughout the production cycle.