In hot, sunny weather, keeping plants in containers watered can take up considerable time. Then there's always the anxiety of how plants will fare when you're away for a well-earned break. One solution is to use self-watering containers. It's actually very easy and inexpensive to make your own.
You'll need two containers which when stacked, will leave a gap between the bottom and top containers. The gap will serve as your water reservoir. Two five gallon (20 liter) food-grade plastic buckets work well, and can often be picked up for free from restaurants or very cheaply from home improvement stores.
You'll also need a one-inch or 2cm-diameter plastic pipe long enough to run the length of the two buckets; a plastic cup, yogurt pot or similar to act as a wicking chamber; and of course some quality potting soil and your plants.
Prepare the Wicking Chamber
Start by preparing the wicking chamber. This should dangle down from the top bucket into the bottom. Stuffed with potting soil, it will draw, or wick, water from the reservoir up into the top bucket.
Use a marker pen to trace an outline of the pot onto the middle of the top bucket, then cut it out. The wicking chamber will need lots of holes all over the sides to allow the water to enter from the reservoir.
2. Prepare the Water Delivery Pipe
Now for the water delivery pipe. Cut one end of your plastic pipe at a 45-degree angle. This will allow the water to freely flow from the pipe into the reservoir without getting blocked.
Cut the top end of the pipe to length so that it stands clear of the final soil level.
Now cut a hole into the bottom of the top bucket, so the pipe can pass into the reservoir. Make sure it’s a snug fit by tracing the outline then cutting to size.
3. Make Some Drainage Holes
The top bucket will need some drainage holes for healthy root growth. Drill lots of quarter-inch (5mm) holes into its base. You can go for a random pattern or an orderly effect – whichever you prefer.
Assemble Your Container
Now it's time to assemble the container. Insert the top bucket into the bottom bucket. Fill the wicking chamber with potting soil, firming it in for good contact, then slot the chamber snugly into its hole. Slide the water delivery pipe into place, pointy end down. Fill the top bucket with potting soil, moistening with water as you fill.
Plant Up Your Self-Watering Pot
You can plant several plants into the top bucket, according to their spacing requirements. Or set one plant, such as a tomato, at the center. This allows you to cover up the remaining soil surface, which will reduce evaporation – especially important in hotter climates. Use a lid for this, cutting appropriate holes to accommodate the plant and pipe. Alternatively use a thick garbage bag secured at the sides with rubber bands, a bungee cord or string.
You could also add a shallow ring of organic fertilizer around the plant. The moist potting soil will gradually draw the nutrients down into the soil to feed the plant's roots.
This is a fantastically elegant solution to daily watering. We’d love to hear your methods for making watering plants effortless – drop us a comment below.