11. Observations

The cotton stips are a mixed bag. The thicker ones are working well. The two coming out the top of an upright bottle are working well. Others are dry at the point of entry into the ground. Perhaps it's just too hot. 

Another observation is that the cotton strips are starting to disintegrate. They are biodegradable after all so it's not surprising yet somewhat unanticipated.

I didn't want to replace them with the thick ropes because then the students won't see what works and what doesn't. So I put the ropes next to the cloth, with the usual few nails to weight them down. But low and behold, the ropes floated to the top! I found some rocks and used a macrame technique to tie them on. So far so good. I also dug the ropes down deeper to the roots.