Grow your samples on your own before you put them into the soil.  Now it's even easier :)
I focused on minimizing 1st layer surface to speed up the print. 
The spacing between pyramids and pyramid to edge is the same - 1 mm so you can easily cut is and keep clean look. You can make even chocolates with this - nobody checks it. Please keep in mind that I don't recommend to use it with food.
There are 2 models - cut and uncut. I recommend to print cut, or download uncut and cut in slicer acording to your needs. The pot should have a drain on the bottom, so I don't recommend to print it uncut.