I’m getting back to bonsai. But I now live in SoCal Zone 9B where summers can reach 120F. (It’s a lot different when I was in KS). So question is, any soil mix I can use that retains water longer for the juniper to drink but not long enough to cause root rot? I work during the day and do not have the opportunity to water multiple times a day. Probably one in AM and one in PM. I have a drip system for other ornamental plants that goes off three times a day. Not sure if that can be used for the bonsai. Thanks.

I cannot relate to your climate at all. Just want to let you know that I am growing junipers in close to 100% organics in sweden, similar to usda zone 7 but with a lot of more rain than over at your place and not that hot summers. I need to put them into unheated greenhouse in winter to awoid root rot. In summer they thrive with watering every 2-3 days.