Welcome,
@Kevin235. As Gigi suggested, knowing your location is very helpful for us to know. Different climates require different growing techniques.
I'm also in Florida, Vero Beach, and that's zone 10a. So if you have cold and wetness issues, that's about 180 degrees different than my conditions here in SE Florida. That being said, my experience is mostly from my growing and propagating in NE Mississippi, 25+ years, zones 8b and 8a. I've only lived in Florida for 5.5 years. Since my experiences and knowledge comes from growing in both a temperate as well as a subtropical climate, I can usually answer questions regardless of the questioner location. During the last 30+ years, I've grown and propagated many 1000's of plumeria. I also owned and operated a tropical plant nursery, specializing in orchids and plumeria. Five months ago I moved from my large property where my nursery was, and now live on a tiny piece of property. I've greatly downsized my plant numbers. Before I moved I had 92 varieties of plumeria. I only brought approximately 36 varieties in the move. My days of growing and propagating are now quite limited and my selling days are pretty much done.
I've never used pumice in any of my potting soils, and my experience in growing tropicals in pots go back 50 years. Unfortunately, since I lack that experience, I really can't tell you much about the use of pumice. I can tell you that there is absolutely no nutritional value when you use pumice. I'm a great believer in the use of perlite though, but again, just like pumice, there's no nutritional value. I would assume that using pumice is about the same as using fine sand, but just like pumice, I've never used sand either, other than to experiment with different soil components. I've used all sorts of media for potting soil though. I'm an "experimenter", so during these 50 years of growing and propagating, I've experimented with all sort of soil (the vast majority of orchids don't require any soil (aka dirt), but most of those orchid media are wood-bark based. When it comes to potting soil (and what I use to amend our sandy/crushed shell "soil"), I've settled on what works best for me. I want something organic in my potting soils, so I use composted cow manure. That's too dense and moisture retentive by itself, so I add another organic, cypress chips. I add to these two components, perlite, and I prefer the #3 or #4 size of perlite, extra coarse/chunky. The cypress plus the perlite open the soil as well as ensure great draining. Having the composted cow manure gives me nutritional value (as well as the slow breakdown of the cypress) as well as moisture retention. My formula is: 2 parts composted cow manure, 1 part cypress chips, and 1 part super coarse/chunky perlite. To every 5 gal. I add a balanced, slow release fertilizer, a large handful per 5 gal. of potting soil. With my potting soil, I don't think that it is possible to overwater. Of course, you need pots that have plenty of drainage holes.
You might like to friend or follow me on FB, Kenneth Ramsey Vero Beach and/or join my group on FB, 'Treasure Coast Tropical Plants'. I'm far more active on FB than I am here in NGA.
