Indoor gardening is practiced all over the world as a means of growing food and flowers if limited or no outdoor space is available. Growing systems have become easier and cheaper to build, and with the right setup, growing indoors can provide enough food and flowers for the entire year.
Conditions for indoor growing systems have to be maintained to a high standard. Plants must have at least four hours of direct sun or alternative lighting, be kept at temperatures between 50 and 85 degrees Fahrenheit and be watered regularly with clean water low in chlorine and fluoride.
Greenhouses are buildings or structures built for the purpose of growing plants indoors. Greenhouses have controlled environments where heat, watering and humidity can be adjusted according to the crops being produced. Greenhouses are heated by the sun through thermal plastic that traps the heat and creates humidity by water evaporation, or by a controlled thermostat.
Another indoor plant growing system is hydroponics. Hydroponics grows plants without soil, instead using a specially formulated nutrient solution to provide the sustenance that plants would normally get from water. Plants are placed in a system where their roots have access to the nutrient solution through the planting medium they are growing in, such as perlite, or float freely in a nutrient bath.
Unlike outdoor planting, artificial light may be required to provide plants with enough light to produce food to grow. Specially designed grow lights provide the correct light wave length best absorbed by the plants in a garden. Red and blue light wave lengths are best absorbed by plants. Natural, full spectrum and balanced growing lights cost more because they provide both red and blue light at once, as opposed to bulbs that provide one at a time.
Foliage diseases are less likely on indoor plants. Soil pathogens can become a problem if the plant is not given enough water and light, or is not correctly fertilized. Also, indoor pests such as mealybugs, aphids, spider mites and thrips can become a problem if left unattended. Removal of these pests with a cotton swab and rubbing alcohol will usually be enough to keep them under control.