HI, this is an design to help plant continue to grow well during the hot summer and it's support free design, hope you like it.
Just to update one important point when you use spike you must make sure spike is push deep and no above surface or else the effect will not be there.

Just reminder, inside have 2 different type of design, see which one suitable for you.:)

I have upload in pinshape: https://pinshape.com/items/10082-3d-printed-spike-water-root-planting

I have upload in thingiverse: http://www.thingiverse.com/thing:1015460