How To Build a DIY Grow Box at Home

How To Build a DIY Grow Box at Home

You’ve probably experienced several occasions when you may have needed to practice indoor gardening. Whether the climate in your area isn’t great for the plants you want, or you simply want to keep them more protected, an indoor growing box is a great solution. Building your own grow box isn’t as hard as it might sound, but there are some drawbacks to going the DIY method. In this post, we’re going to break down what you need to know in order to build your own growing box. Let’s get started!

Why Build a Grow Box?

When you’re doing indoor gardening, setting up the grow box is among the most important things you can do to ensure your plants grow up strong and healthy. By setting up a small grow box, you can create the perfect weather by establishing ideal conditions like lighting, ambient humidity, and temperature. In building my own grow box, I get to choose the perfect dimensions and layout for my needs. All aspects of my small, indoor garden are mine to control.

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Does a Grow Box Really Work?

Absolutely! A growing box is one of the best ways to fully manage the grow process from start to finish. They can drastically increase yield when compared to growing outdoors, where the conditions can be more unpredictable.

Choosing Your Dimensions

Determining the proper dimensions comes down to what, precisely, you intend to grow. The ideal size of the grow tent or box is among the most important decisions to make. A tent with exaggerated size needs will waste money on materials as well as electricity. A box that is too small will crowd my plants, creating unnecessary competition for water and nutrients. Look up how much space your specific plants will need, and calculate the ideal dimensions of the box accordingly.

Here’s some basic, common dimensions as a reference point:

  • Compact - W: 15 – 18″ D: 24″ H: 30 – 60″
  • Mid-Size - W: 24″ D: 24″ H: 60″
  • Large - W: 36 – 72″ D: 24″ H: 72 – 78″

Creating Optimal Conditions Inside


First, you need to get the proper lights. An abundance of light is optimal, but it is definitely possible to have too much. If your budget permits, LED lamps are best. These emit a complete spectrum of color without producing too much warmth. Lighting technology has grown considerably over the last decade, making indoor grow setups much more effective.

Air Circulation

Air circulation is important for a number of reasons, including keeping pests off of your plants. Proper air circulation can also help prevent fungus, and some plants can’t thrive without it. However, you should avoid pointing circulating fans directly on your plants; this can cause excess evaporation, which can dry out the plants. The fans should push enough air around without being overbearing.


Just like you need to keep an eye on the lighting, temperature is also critical. Most plants prefer to exist in a span between 70-80 degrees Fahrenheit. This can be pushed to 85 degrees in some cases. Many plants, in fact, prefer the upper edge of this range. As with many things in maintaining an indoor garden, consistency is key regarding temperature. The daytime levels, when the lights are on, should experience a consistent range with no more than a 10-15 degree drop when the lights go off, but always look up the ideal grow temperature for what you intend to plant.


Indoor gardens often require high humidity, which is why a box is necessary. If you don’t keep plants that require high humidity in an enclosed space where you can control how much water vapor is in the air, they’re not going to thrive. You can either buy a humidifier to put in your box. Most of the ones designed for gardening will have a monitor on them. If you’re trying to save money, you can pick up a simple thermometer with a humidity gauge, then fill a container with water and keep it in the box. Add or remove water to get to the ideal humidity level for your plants.

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Grow Box Setup

Tools and Supplies

A basic growing box or tent can be built around several different types of frames, but the most common are shelving units with a PVC pipe frame.

For PVC pipe frames, a pipe cutter is essential. Black and white poly serves as the skin of the box; black absorbs light while white reflects it.

It’s also a good idea to have some sturdy tape on hand if you need to secure anything down. Velcro or cable ties will be needed to keep the wiring manageable. Magnets are optional for holding the door shut. Finally, you need your LED grow lights, a power supply, and a humidifier, or a thermometer with a humidity gauge.

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Shelf Assembly

If you’re not into building a shelving unit yourself, you can buy them premade. Metal or plastic is the best shelving materials because they won’t easily mold or rust in the damp environment of the growing box. The tallest shelf will be used to hold the lights in place in the next step.

Light Shelving

If you buy a premade shelf kit, you may need to cut make small adjustments for the lights. Measure around your lights, then cut the shelves accordingly. Make sure you cut the hole wide enough for the lights to fit through, but not wide enough that they fall. You can duct tape the lights down to make a stronger fit.

Run the Wiring

When I built my growing box, I ran my wiring through the frames' V shapes on the shelves to keep it in place. Along the sides, I used Velcro to hold the wire tight to the post. It is key to follow safety instructions on the lights' wiring. You can run it however works best with your specific setup, just make sure the electronics aren’t near any water, and the wires are crimped or getting in the way at all.

Position the Poly

Unfold the sheet of poly, draping it over the frame, with the black side facing out, and the white/reflective area on the interior. You may need two people with this part to make it easier. Align two of the poly's edges with the top and a single side of the rack. Hold the poly so that it has an edge running along the edge of the top shelf. A lot of slack should be hanging at the rack's bottom. Then shift the poly around one side, meeting up with a front post. The slack will form a door.

Tape the Poly

Duct tape works well for securing the poly. The best way to do it is to tape the poly to the top shelf's front edge. Once it is secure, take the slack at the bottom, pulling it under the shelf's four feet of space, enfolding the bottom as well. Trim the bottom flush with the posts at the sides. Pull the poly tight about the rack, covering both sides and the back. Now only the front remains uncovered. Trim and tape the sides, folding the corners of the poly like a present's wrapping.

Fashion the Door

Finally, using the excess trimmed from the side, cut a piece that will fit the front nicely You can tape it to the top and tape the door's back down. A couple of pieces of duct tape help hold the door closed, although magnets could be used. And thus the DIY growing box is complete.

Is DIY For You?

A made a home growing box has its limitations. First, it will almost always be flimsier than something you buy from a professional, and it’ll likely be harder to fully control temperature and humidity. If you’re not as handy as you’d like, or this is your first time growing a plant indoors, you may want to consider buying one instead, especially if you have to buy all of the supplies too and don’t have any already on hand.

Let us know what you think about this walkthrough in the comments section below!

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