This guide outlines the principles of meeting plant nutrient needs through proper fertilizer selection, formulation, and application. Plants require 17 essential elements for growth, with fertilizers providing the mineral nutrients not derived from air or water. The document explains the differences among macronutrients, micronutrients, complete and incomplete fertilizers, and how fertilizer analyses indicate nutrient composition. It describes the use and calibration of fertilizer injectors, emphasizing the importance of injector ratios for accurate nutrient delivery. Methods for calculating fertilizer stock solutions are detailed, including examples for both complete and custom tank mixes. Finally, the guide highlights best practices for verifying fertilizer concentrations through electrical conductivity (EC) measurements and maintaining injector calibration to ensure consistent nutrient management in greenhouse crop production.

Increased fuel costs and colder than normal winters make heating costs a significant burden on many greenhouse operations. So, how can growers deal with high energy costs in the greenhouse? This publication covers energy conservation, alternative fuel choices, growing temperatures and production practices.

Plant growth regulators (PGRs) are chemicals that are designed to affect plant growth and/or development (figure 1). They are applied for specific purposes to elicit specific plant responses. Although there is much scientific information on using PGRs in the greenhouse, it is not an exact science. Achieving the best results with PGRs is a combination of art and science — science tempered with a lot of trial and error and a good understanding of plant growth and development. good understanding of plant growth and development.

Irrigation management of nursery crops grown in containers can be difficult since many factors influence the decision of when and how much to irrigate. These factors include weather, substrate properties, crop water use, crop canopy, irrigation system performance, and water quality. In making the decision to irrigate, many growers rely on their experience with the crop and the substrate in which it is grown, current weather conditions, or forecasts.

Plants use energy from light to power photosynthesis, a process that converts light into sugars, serving as their primary source of energy. In turn, this captured energy supports nearly all life on Earth. That makes light one of the most important factors in agriculture, gardening, and life. Despite its importance, light is often misunderstood, overlooked, or poorly managed. Whether you are a homeowner tending a few houseplants or a professional grower, learning how to measure and harness light can be a powerful tool in growing healthy, productive plants.

The USDA agricultural census offers valuable insights into key agricultural commodities nationwide and by state. However, its data can be difficult to interpret directly. This publication provides a recent historical analysis of significant horticultural crops in Virginia, presenting USDA data in a more accessible, visual format for easier understanding and practical use.