Does anyone know how to make self watering pots for 20" outdoor pots?

I buy mine at Home Depot. So easy to water what plants I have them in. I have two that I use for herbs, and two of my strawberries are in them.

If you need to water while away I tried this last year when I was gone to California for 10 days.My balconey faced the south and I often had to water TWICE a day.I didn't want to have that haasel for my friend so I used plastic bottles up to 2 liters with their plastic lids pierced.I filled the bottles up with water and them plunged them into my conatiners.I watered well and my friend did not need to water more than every 3 or 4 days.He simply refilled the bottles with water,after he manually watered(The soil needs to be wet in order for the bottles to wick out the water as the plants needed it.)

I use packing peanuts in the bottom of the pots and fill in with potting soil. The peanuts give space for the water to fill in around them and the plants roots have room to expand. Anyway it works well for me.

I put a disposable diaper in the bottom of my pots before I add dirt. It helps to retain moisture in your soil.

I have used plastic pop bottles with a few holes punched out of the lid when I've been out of town for a few days. This way the plants are slowly being watered every day. Just check to make sure the water is continuing to slowly drain. Even with self watering pots you have to refill every third day or so. This is very similar. It looks better when hidden in the back of the plants.