Take your container garden to the next level with a grow box. Unlike regular planters, grow boxes are self-watering. They ensure an even flow of water to the roots of your ornamentals and vegetables, so the plants never suffer from drought stress. Since planters normally dry out much more quickly than a garden bed, grow boxes offer a clear benefit, with their built-in irrigation system. For single plants, all that is needed is a small grow box that you can make from common materials.
Drill a ½-inch hole in the center of the bottom of a 5-to-10-gallon plastic bucket. Drill 8 to 10 ¼-inch holes around the center hole. Drill a second ½-inch hole near the edge in the bottom of the bucket.
Twist a piece of white cotton fabric to form an 8-inch-long wick. Alternately, use the wicks sold for outdoor oil lanterns.
Push the wick through the ½-inch hole in the center of the bucket so that 4 inches hangs below the bucket and 4 inches is inside the bucket.
Set the bucket with the wick inside a second bucket. The bucket will only slide about two-thirds of the way into the second bucket, forming a reservoir between the two buckets.
Insert a 3-foot length of ½-inch-diameter PVC pipe into the second ½-inch hole. This is the watering tube for the grow box.
Fill the bucket to the rim with a soilless potting mix. Use only soilless mixes, as these absorb and distribute the water best.
Sprinkle 2 tbsp. of slow-release fertilizer around the inside edge of the grow box, on top the soil. Plant your transplant in the center of the bucket to the same depth it was in its nursery pot, and then cover the top of the soil in the bucket with a piece of black plastic mulch.
Pour water into the watering tube to fill the reservoir. Refill the reservoir every three to five days. The wick absorbs water from the reservoir and distributes it to the potting mix. The fertilizer slowly leaches into the soil as the plant requires it.