I know what you are saying but if you can envision how much height is above. What was happening with me I would water the pot. Of course to water it sufficient I have to sit it up. Remember you will not get any rain water or any moisture only what you give the pot by sitting it up.
Once you lay it down because the top is so high all the moisture will go to the bottom. The top dries out real quick. So that part of the soil sucks up any small amount of excess you might get around the lip.
Okay, get a cup fill it with water and lay it on its side. What is left in the cup.
As I said these pots are cute but they take some thinking out of the norm to keep anything alive in them.
Hetty when you said it was not getting enough moisture I thought you were having the same problem I was having. Maybe my process will not work for you. My pot did not get enough rain water when it rained. I had to put the hose up to the pot or sit it up to give it a good soaking. It was heavy but I am really strong for my size and since I had the diaper and using sucs I did not have to do it often.