Don't let cold weather slow down your classroom's gardening efforts! Use winter months to extend 'green' experiences by cultivating indoor gardens.
Most schools garden during the fall and spring, but by incorporating plant activities indoors you can reap the benefits of hands-on, interdisciplinary horticulture lessons year round. Using grow lights or sunny windowsills, your class can experiment with growing a wide range of plants, from houseplants and blooming bulbs to edible crops like radishes and lettuce. Kids get excited watching nature in action indoors while most everything outdoors is tucked in for the winter.
Indoor Garden Options
The simplest form of indoor gardening is to place plants in windows that receive a decent amount of light. Windows that face south and west are best and they usually receive enough light to grow leaf and root vegetables (beets, carrots, lettuce, onions and radishes) and herbs. East and north facing windows receive less light and are ideal for many houseplants. You will need to spend a few days monitoring your window space to determine how much light is naturally available for an indoor garden.
Grow lights (fixtures with fluorescent lamps designed to hang low over growing areas) are a more effective way to produce indoor crops. With grow lights, you can control the amount of light your plants receive and can expand your crop options to fruit crops like tomatoes and strawberries. For a selection of prefabricated GrowLabs designed specifically for youth garden projects, visit NGA's Gardening with Kids Shop there are a number of models to choose from. Or you can make your own using the designs recommended in the Resources section below.
Preparing Indoor Growing Spaces
To prep a windowsill garden area, your main goal is to protect the windowsill or table from water damage. You can place your pots in individual saucers or in a large plastic tray to catch drainage. Have students figure out how many plants you can keep healthy in the space you have available.
To install grow lights, follow the directions included, following all safety precautions. If you plan to build your own light stand, look for an approved design on the Internet or in books. Finally, have your school district's electrician (if you have one) review your construction.
Indoor Gardening Supplies
Plants -You can start plants from seeds or cuttings, or you can purchase plants. Most classrooms begin their gardens with seeds because they are relatively inexpensive and students get to see first hand the life cycle of plants. Local garden centers and seed companies are often willing to donate seeds to schools -- by the end of the summer many companies want to get rid of excess stock. (Seed is dated when packaged, and most businesses will not sell seed with expired dates. But as long as they have stored seed properly, seeds will germinate well even if they are several years old.)
Growing Medium - The growing medium in which you raise your plants is important. It anchors the roots so the plants don't fall over and serves as a reservoir for water, air, and nutrients taken up by the roots. The best medium to use in pots is soilless potting mix, made from peat moss (or coco peat), vermiculite, and/or perlite. Some also contain added nutrients in the form of slow-release fertilizer or mineral amendments. Soilless potting mix is light enough to allow for good water drainage, root aeration, and root movement, yet heavy and spongy enough to provide anchorage and to hold adequate water and nutrients. It's easy to transport and readily available in most garden stores. Most are sterilized so that they do not contain weed seeds, insects, or diseases that could flourish in the favorable conditions of an indoor garden. A final benefit is that it doesn't produce mud, so if it gets on clothing, it brushes off easily.
Containers - You can use just about anything for a plant container as long as it has drainage holes so water doesn't pool around roots. Plastic pots are the most common containers because they are generally inexpensive, can be reused, and are lightweight. Clay and peat pots are also common. You can also make use of school milk cartons, plastic yogurt cups, shallow rectangular growers' flats, egg cartons, and plastic soda bottle bottoms -- just be sure to punch drainage holes in the bottoms!
Additional supplies you may need are plant labels (popsicle sticks and plastic silverware work great), watering cans (try plastic water bottles or milk jugs) and fertilizer (liquid or slow-release).
Tips for Indoor Gardeners
Some things to keep in mind:
The indoor environment does not provide as much light as an outdoor garden. Grow plants with lower light requirements or provide additional lighting with grow lights.
If you move plants from outdoors to you indoor light garden, they may go through an adjustment period and lose some leaves because of changes in light and humidity levels. Give plants time to adjust to the new conditions before giving up on them. Better yet, ease the transition by gradually moving plants to shadier conditions over the course of a week.
Water potted plants as needed. Get to know the moisture needs of the various plants you grow -- some prefer a consistently moist soil while others do better when soil dries out between waterings. Apply water directly to soil and allow excess water to drain. Discard excess water from plant saucers so that soil does not stay too wet. (Pouring water into the saucer under a pot so that soil can absorb it slowly is better for some plants: for instance, African violets can suffer from rot if water is frequently splashed on their leaves.)
Check regularly for pests such as aphids and fungus. Remove and treat plants with problems quickly to avoid having the problem spread to others.
When choosing a location for your indoor plants, consider accessibility. Students will need room to water and monitor plants and custodians will need room to clean around your indoor garden. Make sure there is plenty of room so plants are not knocked onto the floor by accident.
As with any youth gardening project -- remember to HAVE FUN!
Resources -Grow Lights