Indoor Garden Design and Build

6 Things You Should Know Before You Grow Indoors

Where’s the perfect place to set up an indoor garden—a spare bedroom, an attic, an outhouse, a garden shed, a basement? A lot depends on your chosen application—perhaps you’re keen to start growing your own culinary herbs like basil, cilantro and parsley and enjoy them all year round? Maybe you want to get a head start on the outdoor growing season by propagating vegetable seedlings under some fluorescent T5 grow lights? Or perhaps you want to go the whole hog and create a high light intensity indoor garden for flowering and fruiting larger plants? This still leaves the question: where do I do it? Different people set up indoor gardens with different motivations—but there are some fundamental things all aspiring indoor growers would do well to consider before starting out.

1. Good Insulation: Happier Plants and Lower Energy Costs

The more insulated your indoor garden, the easier it will be to grow plants in it.

Ask yourself this simple question: what is your house or apartment made of? Do you live in an 18th century French barn conversion with three-foot thick stone walls or a prefab wooden duplex with the statutory minimum amount of crappy insulation from the 1970s? The less insulation your dwelling affords you from fluctuations in ambient temperatures outdoors, the more effect the outdoor seasons will have on your indoor garden. And surely the main point of an indoor garden is that YOU are in control of environmental factors, not the other way around?

The better insulated your home, the easier and more affordable it will be to maintain a healthy and thriving indoor garden. Thick, stone walls are ideal. Cheap wooden homes with poor insulation are ... the opposite of ideal!

So, if you live in a poorly insulated building, the location for your indoor garden within the building itself becomes even more important. Think cool. If you can choose a room with a north-facing wall (in the northern hemisphere at least!) as it will heat up less during the summer months and, as a result, it will probably be a whole lot easier to regulate its temperature.

Got access to a cellar or basement? This is great news! The earth is a fantastic insulator so growing subterranean is ideal from an insulation perspective. One potential drawback is the potential for high humidity problems, but this can easily be rectified by investing in a dehumdifier and proper ventilation. Also, take a moment to check for drainage options for getting rid of old nutrient solution.

Attics may seem like a nice out of the way place for a small indoor garden, but they can often be subject to extremes in temperature due to their elevation, exposure to sunshine, and poor insulation.

Attics can be problematic. Not only is access often limited to a small square hole (difficult to pass larger pieces of equipment through such as reservoirs and trays) but there's also often the issue of limited vertical space and more susceptibility to extremes in temperature. If an attic is your only option insulation should be top on your agenda.

Finally-garden sheds, static caravans and other low insulation buildings are best avoided!

2. Ventilation

One of the most often over-looked factors.

As an indoor gardener you've got to deal with two major challenges as soon as you switch on your grow lights.

1)   You need to somehow combat the build-up of excessive heat generated by your grow lights.

2)   You must keep the air inside your garden constantly "fresh"-maintaining adequate levels of CO2 and relative humidity during the daytime so your plants can photosynthesize effectively.)

Both these challenges can easily be met through adequate ventilation-that is, removing old, warm, "spent" air and replacing it with cooler, fresh air. Most gardeners achieve this by using extraction fans and ducting.

Five sizes of inline ventilation fans. These fans are used by indoor gardeners to bring air in and out of their gardens.

All sounds simple so far doesn't it? Yet inadequate ventilation is a problem that creeps up on most new growers time and again. Why? Well, one theory is connected to the exponential growth of your plants. Everything seems fine at the beginning when your plants' needs are small and you're probably only running one or two grow lights, perhaps some fluorescent T5s that don't generate so much heat. But, as your plants grow exponentially, so do their needs! It's only when your plants are bigger, say at the end of the vegetative stage or a few weeks into flowering, that deficiencies in your ventilation system start to bottleneck plant development-just as your plants' needs are moving into the corner of the "hockey stick" - it's a glass ceiling that many growers simply don't see coming.

Growers use ducting to channel fresh air into their indoor gardens and also to extract warm air to the outside world.

Look for a hole, a vent, a window, something to give you the opportunity to extract your garden's warm air to the outside world. The key word there is "outside" - don't be tempted to simply vent the air out of your grow room into another room in your house. Before you know it you'll simply be re-circulating old, spent (CO2 depleted) air and defeating the point-not to mention humidity and damp issues.

Extraction has the most positive effect on reducing temperature when it is removing air from the top of a room - as hot air rises.

Consider the route your ducting will take between your extraction fan and the vent hole-the fewer bends the better for your fan efficiency.

Many growers create a custom cover for the window or vent in their grow room, cut a hole in it and fit a flange so that ducting can be securely fixed in place. This has the benefit of helping to keep pests and light out while still providing an effective extraction route.

Intake air should ideally be drawn from inside your home - a nice cool room adjacent room (sometimes called a "lung room") is ideal. Drawing icy air from outdoors during winter and blowing it directly on your plants will not please them. Be sure to use a bug screen on all air intakes. They cause 10-30% air resistance but the extra protection from bugs, mold spores and pollens is worth the extra cost of speccing your fans a little higher.

3. Water and Drainage

Keep hosepipes to a minimum!

How far away from your proposed garden is your nearest water source? Are you going to require endless yards of hosepipe to get water to your indoor garden? Similarly, have you worked out how you are going to deal with run-off water or nutrient solution (i.e. liquid that you need to dispose of somehow) - believe us, carting bucket after bucket of water up and down stairs quickly gets boring.

A Reverse-Osmosis water purifier can be fitted easily without the need for a plumber. It produces pure, uncontaminated water which is perfect for growing plants.

Water Quality

Some research into the quality of the water in your area is time well spent. Measure your water's conductivity-this is a quick and easy test you can perform yourself with a conductivity meter (quality models are available for around $40) - also known as an EC meter or TDS meter. A reading of over 200 PPM or 0.3 / 0.4 EC may be an indication that you should invest in a water softener and reverse osmosis water purifier to remove carbonates, chlorine, chloramines and other contaminants.

You should consider allocating a space to keep a large container (50 or 100 gallons) such as a rain collection barrel to mix and store your nutrient solution. Some growers recycle their spent nutrient solution by using it on their outdoor gardens (especially lawns and ornamental plants) diluted 50 / 50 with water.

4. Ceiling Height

High ceilings are sent from the heavens as far as indoor gardening is concerned. It's not that we necessarily want to grow our plants tall, but the extra volume of air afforded by high ceilings makes for easier environmental control. 8 ft ceilings are adequate, but 10 ft or higher makes your life easier. Additional ceiling height gives you more flexibility when it comes to choosing a growing system and reflector. Raising the height of your grow trays takes the strain off your back and confers additional benefits including easier drainage and nutrient in re-circulating systems- all of this thanks to gravity!

Higher ceiling make life easier for indoor gardeners, not necessarily because they want to grow tall plants, but because of the extra volume of air the room holds - making environmental control much easier.

5. Electricity

The watts can add up fast. High intensity discharge grow lights, T5 fluorescent arrays, AC units, block heaters, pumps, timers, extractors and oscillating fans-not only do these items require lots of plug sockets, but they need to be connected to your electricity supply safely without risking overloads.

If you're looking at a room with just the standard two, three or four plug sockets-consider getting some extra sockets wired in as a top priority.

When working with electricity you really need to know what you are doing and pay careful attention. There's no room for guesswork when planning your indoor garden's electrical system.

The golden rule is: once you have planned your installation, it's essential that you ask a licensed electrician to check it before proceeding.

Make sure you use lighting controllers to safely drive your HID grow lights. The high inductive load created when HID grow lights switch on will fry most standard segmental timers.

6. Pest Protection

All carpet should be removed from any space where you are planning to grow as it can harbor no end of pests and pathogens. If removing the carpet is not an option, you can lay down protective plastic sheeting. Remember, your indoor garden should be as easy as possible to keep squeaky clean. A laminate floor that is easy to mop is ideal. 

Air intakes should use a bug screen so that you don't inadvertently suck bugs into your garden.