Watering is an ongoing challenge for school greenhouse growers. Water is the solvent that carries minerals from the soil to plants via the roots. A raw material used in photosynthesis, water enters the roots as a liquid and exits the leaves as a vapor as it's transpired.
You and your students will want to start some seeds in their permanent containers or beds, if you are raising crops that do not transplant well (such as beans, peas, cucumbers, melons, squash, carrots, beets, and radishes) or if transplanting them later on isn't an option. You may choose to sow other seeds in temporary containers, and later transplant them to larger containers or greenhouse beds.
Plants require certain nutrients in order to thrive and grow. These are not actually food, but chemical elements or minerals that are vital to helping a plant use the sugars (the real food) that it produces during photosynthesis. Nutrients are normally found in soil, in decomposed organic matter such as compost, and in commercial fertilizers. The "macro-nutrients"--those required in the greatest amount by plants--include nitrogen, phosphorus, and potassium.
Soil found outside stores and releases nutrients, provides plant support, and creates passages for air and water. It contains living thing--bacteria, mites, and worms, as well as nonliving substances--small particles of sand and clay. Greenhouse soils need to be lighter than garden soils, because frequent watering tends to pack soil down.
Soil-filled greenhouse beds, near ground level or raised to 24 inches, are ideal for creating indoor planting habitats. Since beds (particularly raised) typically contain more soil than containers do, they promote good root growth.
Plant physiologist, Ray Wheeler, examines a lettuce crop to better understand how plants can support life in space. (Photo credit: Ray Wheeler)No question about it--plants are vital to our existence here on earth. They provide us with the essentials of food, oxygen, and shelter. But have you ever stopped to think about how these benefits would translate beyond our planet?
Gardens are an excellent teaching tool for youth because they providing important hands-on learning activities and inspire kids to discover the wonders of their environment. These experiences are valuable for all children, but can be especially meaningful for children whose exposure to nature is limited, such as those with special needs. These kids face challenges and barriers in the traditional outdoor setting, and instructors and parents are often times hesitant to involve them in gardening activities.
Educators who work with youth garden programs are quick to share the benefits they have observed, such as children who are transformed from hyperactive troublemakers in traditional classroom settings to eager and conscientious caretakers in the garden, and students who suddenly grasp connections between science and real life after participating in hands-on gardening experiences.