Indoor Gardening Basics

There are many reasons to start an indoor garden; to grow veggies all year 'round, to keep flowers blooming in winter or summer, or maybe you live in an urban area with limited space or poor soil. When you garden indoors, it's important to understand the differences between outdoor and indoor gardening, even though the needs of the plants are essentially the same.

Gardening is a hobby that requires planning and maintenance. Outdoors, plants can rely on nature to provide air, light, and water. While you can add water or nutrients when necessary, you can't prevent weeks of relentless sunlight or a cold snap. Indoors plants rely on you alone; only you can give them what they need to thrive!

In an indoor garden, you completely control the environment. You control water, light, temperature, ventilation, humidity, carbon dioxide, and soil nutrients to provide your plants with optimum conditions. While outdoor seeds are generally limited to one growing season, indoors you can create a semitropical climate that will support multiple harvests. Understand that increased plant activity, from planting and propagation to cultivation and harvest, results in increased maintenance. The reward for your extra work, however, can be a greater yield in less time and space than a traditional outdoor garden.

Working With Your Space

Space is usually the most limiting factor in planning an indoor garden. If you don't have a spacious area that receives lots of sunlight, contain your space for efficient use of your HID lights. Unused closets and basements often provide the best areas because you can control temperature and humidity with some precision. Also consider traffic patterns; the garden room should be relatively isolated so that climatic conditions aren't interrupted and so that the inevitable piles of pots, flats, or spilled soil won't wreak havoc on your own environment. A concrete (or otherwise washable) floor with a drain is very convenient. For carpeted or wood floors, you can use drop cloths, visqueen, and plastic trays left over from seedlings to make cleaning easier and to minimize moisture damage.

The size of your garden room will determine not only the number and size of the plants you can grow, but also the HID lighting wattage you need. Plants in containers will be approximately a foot off the floor, and your lights will hang a foot or more from the ceiling. Depending on the height of your room, this may leave four to six feet for maximum plant growth. One 400 watt system will work well for small rooms or the average closet with around 10 to 40 square feet of floor space. For large spaces of 40 to 100 square feet, use a 600 or 1000 watt HID system. Keep in mind that you can cluster seedlings together in large numbers, but you shouldn't let growing, maturing plants touch one another or block one another's light.

Creating The Environment

Once you have selected and isolated a space, cover the walls with a highly reflective material such as flat white paint or reflective mylar. Reflective material will significantly increase the amount of energy available to plants by reflecting more light onto your garden. You should keep airflow constant with one or two oscillating fans, but be sure fans don't remain in a fixed position for too long as this can cause windburn, or dry out young seedlings. While an open door or window may do the trick, you can use an exhaust fan attached to a thermostat to bring in fresh air while venting hot, humid air out of your growing space. You can also vent warm air from your indoor garden to other areas of your house to reduce your heating costs during cold seasons.

A 10-by-10-foot garden may need as much as 30 gallons of water per week, which you can easily supply with a hose in the room with an on/off valve attached to a spigot or faucet inside the house. This will be a year 'round operation, however, so don't plan on running a hose from an outdoor spigot. Watering wands help to reach all your plants easily, and prevent the breaking of branches when watering dense foliage. While it can be helpful to have a hot and cold water source in your garden to regulate water temperature, please note that hot water pipes contain calcium and lime which can cause significant pH shift in your hydroponic reservoir. Many hydroponic gardeners never use hot water, but instead fill a large container with water from the cold tap and heat it with a reservoir heater before adding it to their nutrient reservoir.

Light movers don't increase the coverage area of your light but significantly improve the dispersal of light throughout your garden. You should mount light movers securely in a level position. If you want your lamp to remain stationary, mount it on one or two ceiling hooks strong enough to support about 30 pounds. Your light should be in the middle of the growing area for maximum coverage. Use a chain or a rope and pulley to adjust the height of the light; this also facilitates moving the lights out of the way for watering and maintenance.

With everything in place, you'll be ready to move your seedlings or rooted clones into the room. Huddle the plants closely, about 24 inches from the lamp, making sure the light won't burn their leaves. Thin young plants as they grow and develop to give them the room they need so that the healthiest, most vibrant plants can thrive without interference from their weak, pest and disease-prone siblings.

NOTE: It's extremely important to keep your lamp dry! A hot HID bulb may break if it comes into contact with just a few drops of water. In general, handle your lamps with care. These small, intense light sources can burn your plants if not positioned correctly, and can be electrical and fire hazards if not properly installed. While you don't have to be a professional electrician, or even hire one, to set up your indoor garden, consulting one can save you time and money. There are many different types of lamps and bulbs; be sure that your lamp meets your needs, as well as the needs of your plants.