How to Build A Grow Box

How to Build A Grow Box

A grow box system is ideal for most people because it allows you to have total control over your growing environment and other aspects such as lighting, watering, pest control, nutrient intake, ventilation and air control.
Building your own grow box and what size it should be is totally up to the individual and his or her specific needs such as what kind of crop size you are looking to grow, space consumption and other variables. Here is a basic guide on how to build a simple grow box easily using some basic plans for a 4’ x 4’ grow box – you can add or subtract lumber dimensions to your specific needs.


– Six 4’ x 4’ plywood sheets, ½“ thick
– Wood screws
– Drill or screwdriver
– Saw
– Two standard door hinges for cabinets
– Wood glue or caulking
– Two 6” ventilation fans (standard fans or computer fans)
– White paint, mylar or other reflective material


Start off by placing a plywood sheet on the ground and stand another sheet next to it lining them up straight. Drill some screws into the wood securing it firmly to the other piece. Do the same thing on the opposite side of the plywood placed on floor and, once complete, add on the two remaining plywood walls. You should now have five sides of your box complete with one wall left. Place the final plywood sheet on the top, line it up perfectly with all the other sides, take the hinges and screw both of them in on the same side of the sheet, each one about ½” to ¾” away from the corners. After this is done, open and close the plywood sheet making sure it fits tight when closed and that it also opens properly – this will be the door for your box. It is also wise to use 3 to 4 screws per side of the plywood for a more solid grow box.
Now that your grow box is complete, seal the inside with caulking or wood glue making sure every side and corner on the inside is sealed really well (excluding the sides of the plywood sheet with hinges that opens, of course). Then let the glue set until it is completely dry.


A successful grow box would not be complete without adequate ventilation – a healthy growing environment requires a constant flow of fresh air into the box and the spent air and heat being extracted out of the box.
For this part of the process, you’re going to need to saw or drill two 6” holes into the box, one preferably in the middle of one of the side walls of the box and another on the opposite wall somewhere a couple of inches from the “roof” of the box (more or less) depending on where you will be positioning your light. Install the highest fan first into the hole making sure that the fan will be blowing the air out of your box as this will be the air outtake fan. Now install the next one with the fan blowing into your box – this will be your air intake. Once installed, check for any light coming into your box via these holes – if you can see light, then use some caulking or glue to seal the fans in.


The installation of your lighting is entirely based on the type of lighting, but more often than not you can follow these instructions for most lighting types assuming that you already have your lighting system.
Drill two small holes on each side of the top of the box, making the holes the same size (or smaller) as the hanging chains or ropes which will be used. Try to match up the holes with the length of the fixture to be used and where the hanging chains or ropes will be attached. Pull the hanging chains through the holes and pull them tight so that the light is about ¼” from the ceiling. While still holding the chains tight, attach them to the plywood using your screws and tighten until they are only just firmly in the wood but not going all the way through. You can also tie the chains together on the outside so that they won`t come loose, but don`t secure them too tightly because you may need to raise or lower your lighting during the course of growing your crops
Once the lighting fixture has been attached, remove the light temporarily in order to apply your reflective material for the walls. The two main materials you could use for this is either to paint the entire inside surface with a white paint, or use Mylar or another type of reflective film and cover as much of the inside surface space as possible in order to get the most out of your light.

Plant(s) Arrangement

This depends on your personal growing situation and if you are growing hydroponically, in soil or another medium. For now, however, all you have to do is place your plants inside the box. One tip is to try and use square pots as they are more space efficient than round ones.
After everything has been completed, perform a final spot check, turn all your fans on to make the air is flowing properly and check your lighting. You can now start cultivating in your new grow box.