So you've got someone with a green thumb on your shopping list, someone with a budding interest in indoor horticulture? Perhaps she is a medical marijuana patient or caregiver, or maybe he just really wants to grow hydroponic tomatoes year-round. Whatever your loved one's motivation, you can help get his or her grow room started with gifts from one of several local emporiums. Rest assured that the staff at these establishments are quite knowledgeable about indoor plant care, able to ask (and answer) the right questions. But if you want to cultivate some knowledge before you set out with your shopping list, read on.
First, find out if your newbie gardener plans to grow in soil or in nutrient-rich water (a/k/a hydroponics, a method of growing plants without soil). Both techniques have their advantages; soil can be cheaper and simpler, but hydroponic systems encourage faster plant growth and need less maintenance once the initial set-up is complete.
Whichever method they choose, indoor gardeners soon learn the basic factors for even the most elementary grow set-up: light, nutrients, and air quality/temperature control.
Some type of ARTIFICIAL LIGHT is a necessity. Plants mature depending on how much light they receive during the day, and they need different sorts of light during their vegetative and flowering stages. Cannabis, for example, thrives on blue hues during the vegetative stage, and requires more red, yellow, and orange light when it flowers. Consider standard or wide-spectrum fluorescent plant lights (less than $10) during the early stages, and $20-70 high-pressure sodium bulbs down the line. (Some lights may need a BALLAST, used to stabilize or limit the current in an electric circuit.) A LIGHT TIMER (like the ones people use when they're on vacation; $15 tops) is an easy way to ensure that exposure remains consistent.
Nutrient needs and delivery systems will vary depending on what type of grow scenario your friend pursues. Organic soil mixtures and fertilizer combinations are easy to find at any garden center; like all plants, marijuana flourishes on a combination of nitrogen, phosphorous, and potassium. Many stores sell "NUTRIENT PACKAGES" — pre-mixed combinations that yield healthy, productive plants — ranging from under $100 to nearly $1000. Another important tool is the pH test kit, which can help you regulate the acidity and alkalinity of the soil or water. These can run from $6 for the little litmus strips you used in middle-school chemistry class to $300 high-tech equipment.
In terms of temperature and air quality, your grower will need a thermometer (duh), plus some combination of FANS, AIR EXTRACTORS, AND FILTERS. Cannabis plants grow best with a lights-on temperature of 70 to 80 degrees Fahrenheit, and like it about 10 degrees cooler when the lights are off. Humidity, which can also be regulated with fans, is another measurement to consider. And depending on what crop he's cultivating, your indoor horticulturalist might appreciate some sort of ODOR-CONTROL MECHANISM, whether it's a $200+ ozone generator or a much less expensive carbon filter (these usually run between $50 and $100).
Of course, any amateur gardener will want to do some serious research before converting her closet into a grow room. Logan Edwards's GROW GREAT MARIJUANA: AN UNCOMPLICATED GUIDE TO GROWING THE WORLD'S FINEST CANNABIS (Sweetleaf Publishing, 2006) is highly regarded and available for $24.95.