Bell peppers are among the many common household varieties of Capsicum annuum, an annual shrub belonging to the nightshade family.
Colors of bell peppers might be green, orange, yellow, purple, brown, or red depending on maturity. Sugar content increases with ripeness, hence red peppers are considered the sweetest and green more bitter.
Botanically speaking, the pepper is a fruit because it has seeds. As demand for fresh bell peppers climbs, supply has been increasingly augmented by greenhouse production.
Though most peppers are imported from Canada and Mexico, as well as the Netherlands, Spain, Israel, and the Dominican Republic, U.S. production is rapidly expanding with new greenhouses popping up across the country.
Even within a protected environment, pepper yields will vary by location, season, plant density, trellis system, cultivar, irrigation, and fertilizer management.
Types & Varieties
The most common greenhouse peppers are the sweet bell varieties—green, orange, yellow, and red. Cultivars are generally hybrids selected for marketability, pest and disease resistance or tolerance, and overall yield and quality.
Among the popular varieties are Parker, Triple 4, Cubico, and Lorca for red; Kelvin for yellow; and Neibla and Emily for orange. New cultivars for greenhouse production are regularly introduced by seed companies.
Cultivars can be distinctly different, enough to require varying growing environments for maximum yield. Some greenhouse growers are also experimenting with field-grown varieties.
Peppers are generally grown in a soil-less culture. Nursery pots or flat polyethylene bags are used. Containers are filled with perlite, pine bark, peat mixes, or sawdust.
At the time of transplanting, seedlings can be irrigated up to 10 times per day, with increased watering during higher light levels and longer days. Night irrigation may be considered during warmer weather.
Ventilation provides a more uniform climate and helps distribute heat. Temperature is regulated, depending on the stage of development and cultivar grown. Generally, temperatures should not exceed 70 to 79°F, with an optimum temperature range of 70 to 73°F.
Plants generally grow up to 6 feet tall during a season with vertical support. Peppers are often trellised with the “V” system or in a double-row trellis via the “Spanish” system.
In the Spanish method, the plant is allowed to grow without pruning. When pruning is required, plants are generally managed with two main stems and pruned every two weeks. It is important to ensure the main stem or growing point remains intact.