How to Build My Own Outdoor Grow Box

Outdoor grow boxes are self contained and grow almost anything.

Grow boxes are self-contained units designed to house plants where there is no existing soil or poor soil. Grow boxes can be used on patios, window sills and even roof tops. A grow box outdoors does not require a lighting system or irrigation drain. They are easily maintained, and with some extra protection can extend growing seasons.

Things You'll Need

• Wood planking sections
• Plywood sheet in 3/8 thickness or more
• Galvanized screws
• Drill or cordless screw gun
• Thick plastic landscape fabric
• Staple gun with staples
• Razor knife
• Soil

Instructions

1. Measure the area where you are planning to place your grow box. If you have an extensive outdoor area but poor soil or you have a patio, a series of boxes may suit your needs. A grow box can be any size from a few inches wide by a foot or two long, to several feet wide and several feet long. The key is for it to be a manageable size for your needs and location. The depth should be at least 6 inches to maintain a good root system, and 8 to 10 inches is optimal.

2. Cut and lay out the pieces of the box according to the size you have chosen. A good rule to remember is the larger the box the thicker the plywood sheeting for the floor should be. The sides should be the same height all around, and remember to add an inch for the thickness of the plywood floor to calculate your inside growing depth. A recommended measurement for a decent planting area is 10-inch plank boards, 6 feet in length with a 3 foot width for the box. This would require 3-6 foot planks and the plywood sheet to build the box.

3. Screw together the sides of the box, forming a box frame. Set this on the plywood and draw a template with a pencil of the inside of the box. This is the simplest way to cut a piece to fit. Cut the plywood, and screw it to the inside bottom of the frame with the galvanized screws, using one every 8 inches.

4. Stretch the landscape fabric over the box and tuck it down into the bottom. Place a staple at the center edge of each side, at the bottom where it meets the side board. Smooth the plastic to one corner on one side of the box, and place a staple in the corner. Crease the plastic over to make a smooth fold and continue making an even crease down the next side, placing a staple in the middle and at the corner. Do this until you have all four sides secured at the bottom.

5. Fold the excess flap left from the crease at each corner to one side and staple near the top edge of the box. Do this with all four corners. Now add staples along the plastic just below the top rim of the box on all sides, every 10 inches.

6. Cut away the excess plastic along the top edge of the box carefully with the razor knife. Fill the box with soil to the top. Compress with your hands. The soil will settle some after watering. Plant seeds or place existing plants in your box.

References

• Casa Sugar: Build Your Own Garden Box

Resources

• University of Missouri Extension: Raised-Bed Gardening