Customizable Self-Watering Seed Starting

Self-Watering System

This is a self-watering insert system for seed starting.  It is intended for re-using containers as seed starting pots; adding the self-watering reservoir, drip trays, and a greenhouse top/lid.

The STLs I've provided were designed for a particular tub I was able to get a few of for free, and are provided as examples, or maybe they happen to work with tubs you have.  The SCAD files are provided to customize to your own tubs/pots with OpenSCAD. 

Base Instructions

The insert goes into the pot and creates a space where a reservoir of water can collect.  The insert has a center hole that is filled with soil and that will draw water up into the soil above the reservoir.  There is an option for a filling pipe (I used ½" pex) and drain holes.

Holes are drilled into the sides of the pots at about the height of the self-watering insert to prevent overfilling with water.

These holes can be eyeballed or there is a drill guide and a greenhouse guide that can be used to align those holes.  The drill guide is quicker to print and uses less plastic if you aren't using the greenhouse guide.  But, if you use the greenhouse guide then there is no need for the separate drill guide.

There is also a tray that can be printed to capture water that overflows from the drain holes.

Greenhouse Top Instructions

The system allows for a second pot to be placed on top of the bottom pot.  The top pot with windows can be covered with cling wrap to form a greenhouse and then snapped on top of the bottom pot.

The join ring has a tight fitting and loose fitting side so the ring stays attached to the pot when the greenhouse side is removed for adding water, etc.

The top pot is cutout with windows using the greenhouse guide, covered with cling wrap, and snapped to the bottom pot via the join ring.  There is a greenhouse ring that can be used to hold the cling wrap in place, or something like a rubber band or garden wire can be used instead.

Soil Displacer

For larger pots, the idea is to fill the pot with regular potting soil.  Then use the soil displacer to push out a hole in the center.  This hole can then be filled with a lighter seed starting mix.  The idea here is that the seed has a chance to sprout in the lighter seed starting mix, but has the ability to grow larger and root into the regular potting soil without re-potting prior to transplant.