How to Build a Self-Watering Planter Box


Forgetting to water your plants is easy to do, especially if you have a hectic schedule. A garden full of dry, dead plants is a discouraging sight, but don't give up on it yet. By building a self-watering planter box, you can cut down on your watering duties and still maintain a lush garden. With a few inexpensive materials and a little time, you can save your plants from a dry, crumbling death.

Step 1

Drill six holes in the bottom of the first tub, just big enough to allow the wicking material to fit through.

Step 2

Thread a length of wicking material up through each hole in the bottom of the tub and pull it three-fourths of the way to the top of the tub. Leave an additional four inches of wick hanging below the bottom of the tub and cut it. This will give you six wicks, each reaching three-fourths of the way to the top of your tub and four inches below the bottom.

Step 3

Set one plastic pot on a flat surface next to the second tub. Mark a spot on the tub about a half inch below the top of the pot.

Step 4

Drill a quarter-inch hole in the place you marked. This will act as an overflow hole to prevent you from over-filling the reservoir.

Step 5

Fill the bottom tub with water up to the level of the overflow hole.

Step 6

Place your four plastic pots in the corners of the second tub, allowing them to fill with water so they stay in place. Set the first tub on top of them with the ends of the wicks hanging down into the water. The pots will prevent the wick tub from stacking too deeply into the reservoir tub, which would reduce the amount of water you would be able to add.

Step 7

Fill the top tub with moist potting mix, pulling the ends of the strings up to the soil surface as you go.

Step 8

Continue filling the tub with soil after you reach the ends of the wicking material. The wicking material doesn't need to reach the top of the tub; it just needs to reach the root zone.

Step 9

Plant your new self watering planter box. The wicking material will pull water up from the reservoir and keep the soil moist.

Step 10

Check the water level in the reservoir every three or four days until you know the rate at which your plants are using the water. To fill, pour water into the bottom tub until water pours out of the overflow hole.

Things You'll Need

  • 2 plastic storage tubs, 18 gallon or larger
  • Drill with 1/4 inch bit
  • Braided polyurethane yarn or fibrous rope
  • 4 plastic pots, 4 inch diameter
  • Pencil or marker


  • Instructables: Self Watering Mini Garden

Who Can Help

  • Spilling Buckets: How to Make a Self Watering Bucket
Keywords: self watering planter box, self watering planter, self watering

About this Author

Angie Mansfield is a freelance writer living and working in Minnesota. She began freelancing in 2008. Mansfield's work has appeared in online sites and publications such as theWAHMmagazine, for parents who work at home, and eHow. She is an active member of Absolute Write and Writer's Village University.