Since greenhouse plants lack the natural benefits of uninhibited sun, soil, and rain, special fertilizers and foods for greenhouse plants are necessary for successful greenhouse crops. Outside plants obtain nutrients from the soil, but greenhouse crops are generally planted in sterilized soil to help control bacteria growth and insect infestations. This removes essential nutrients from the soil. In addition, planting in containers isolates plants and prohibits the transfer of nutrients from nearby soil during heavy rains.

While the controlled environment in the greenhouse is favorable for many reasons, nutrient depletion is a definite drawback. To help keep your greenhouse plants green and healthy, fertilizers and food additives are essential.

Fertilizers and Foods for Greenhouse Plants

Plants require essential elements for proper growth. These elements are boron, carbon, calcium, chlorine, copper, hydrogen, iron, oxygen, magnesium, manganese, molybdenum, phosphorus, potassium, nitrogen, sulfur, and zinc. Plants extract carbon, hydrogen, and oxygen from the air, and the remaining nutrients are obtained from water and soil. A depletion in any of these essential elements can inhibit plant growth.
Fertilizers and plant foods supplement these essential elements and allow the plants to thrive under optimal growing conditions. Some common supplements are peat moss, compost, and water-based fertilizers.

Serious greenhouse gardeners are known to fertilize varieties of plants according to professional recommendations. Certain greenhouse plants often suffer from common element deficiencies. For example, geraniums cannot tolerate high soluble salts. This calls for a water-soluble fertilizer containing calcium and magnesium, often referred to as a geranium special.

Most greenhouse gardeners keep a reference book on hand or consult their favorite greenhouse gardening website for specific recommendations on fertilizers and plant foods. This plant-by-plant look up method ensures proper feeding of plants by pinpointing common problems and solutions.

Some greenhouse gardeners choose to select only organic fertilizers. The backyard compost pile is the most common source of plant food for organic greenhouse gardeners. Other sources include powdered milk, coffee grounds, powdered lime, and aged manure.

If you are interested in learning about the specifics involved in selecting the best fertilizers and foods for your greenhouse plants, your local library holds a wealth of fertilizer knowledge. The specific may become complicated at times making you wish you had a degree in chemistry to better understand the complex processes. Overall, understanding the basic of fertilization in the greenhouse is well within the grasp of the everyday greenhouse gardener.