Self-Watering Planters

Basil transplants in pot retrofitted with self-watering conversion kit. The float appearing at the top of the water-fill tube indicates that the water reservoir is currently full.

On Tuesday I set out to make some self-watering planters. Having purchased some very handy retro-fit conversion kits from Gardener's Supply Company last month, I have been busily setting up planters to accommodate container crops this summer. Unfortunately, I measured wrong and wound up with several wonderful one-gallon retrofit kits that will not work for the some of the planters that I had slated for the task. As such, the time for making my own retrofits had arrived.

Retro-fit insert, ready to go.

The kits I purchased are specifically designed for round planters of a certain size. Placed in the right container, they work beautifully. 

Correctly fitted inserts, ready for potting soil and plants.

The over size round planters we have will require larger collars around the inset in order to fully contain soil above the reservoir. The square and rectangular planters will require suitably shaped inserts. The kits come with enclosed water reservoirs, a fine mesh screen bottom through which roots and moisture can interact, a fill tube--with cover, and a float that indicates when the water level has dropped. They are beautifully designed. 

Planter in progress with building materials.

Planter in progress, with wicks inserted. (Base will move deeper to contain more soil before planting.)

Our homemade attempts are less aesthetically pleasing. Using materials already on hand, they reflect my haphazard style of designing on the fly as opposed to careful measuring and fitting. On Tuesday I had time to design one (very rough) rectangular planter that held water nicely. Although I had thought to use the rectangular planters for quick-pick salad crops--spinach or lettuce--what I had handy were pole bean seeds, so they got planted.

Windowsill seed starters.

Each wick masterfully transfers moisture in these.

The models for the wick theory performed better than expected. As I did not want the planters to remain wet, but rather simply moist, I limited the wicks in the large planter to just three. After all, the single wicks in the windowsill bottle models have remained quite wet. Indeed, the bottle model will wick up water quickly even without potting soil in the top portion.

Planter, completed and planted, holds water well.

Once planted, the rectangular planter filled nicely. Although I had hoped that the wicks would be enough to moisten the entire bed, a day later I discovered that they are not suite to the task. Perhaps the tight fit of the windowsill models served to assist the wicking process. I will have to rework this theory, or break down and purchase some mesh-type plastic for the insert between the soil and the water.

Tomorrow is another day. We will be revisiting this challenge in the coming days and weeks, as time allows. Unfortunately, time is ever short. Although we can allow hours and half-days for working the soil between tending the animals, studies for school, work off the farm, cooking and leisure, we can no longer give whole days to any one project of challenge.

For now we are looking forward to Saturday, when Cynthia will be facilitating a Composting class at the Gardens of Babylon nursery at the Nashville Farmers Market. Please join us at 10:00 am if you are in the neighborhood.