I don't think you can blame the soil for everything. Cacti should do fine in it. June peach drop is quite normal.
Usually due to poor pollination. On tomatoes I agree, they need compost (even peat is better compost than none, not enough in 5-1-1, try 3-1-1). If you're not getting 20-25 pounds of tomatoes on each plant, something is wrong. Some heirlooms will not produce this well, so depends on variety too.
Time and again the one size fits all approach is a very poor one. With fertilizer too. Of course they will say you made the mix wrong.
Most professional soils and almost all potting mixes are peat, pine and perlite, even Miracle Grow. 5-1-1 is certainly not unique.
I did experiments this year too with 5 different mixes in over 40 containers, The most consistent was a 3-1-1-1 mix , pine, peat, perlite, and DE. I thought a pine, peat and DE would do best, but it did not. Having perlite made a difference. Although the differences were only slight. More pronounced with seedlings. As plant matured it didn't seem to make a difference. The control was a Fafard potting mix, it also did OK! I need to experiment more. I will next year. The Fafard mix is a 3-1-1. I also had some in Pro Mix that did decent too. This mix is almost all peat. On some I had to use different pots, so that is a confounding factor in the experiments. Seems fabric containers are far superior for most, but not all plants. I used basil, tomatoes, peppers, and other herbs, and flowers. So other many types of plants the experment really tells me little, only info on plants used.
Plus all gardening is local, what I do in MI tells little to a grower in CA. Understanding soil structure, you can adjust mixes to fit your plant type and environment.

I wouldn't expect the cacti to do very well in the 5-1-1. I reserve the 5-1-1 for the arboreal and moisture-loving cacti such as Dragon Fruit, Holiday Cacti, et cetera.

Avocado are finicky....after transplant, I advise a drip-tray to help keep the root-zone wet. It's counter-intuitive, but it's something that has allowed my avocado to flourish in the hot weather and in its root-bound state. I also fertilize weekly, full strength.

Josh

Hey Drew,

Yeah, tomatoes just don't like 5-1-1. At least when huge yields are concerned. I think they grow so quickly the perched water table doesn't matter. In years past, I grew in commercial peat mixes and, within weeks, the entire 10-15 gal pots were filled with roots. 5-1-1 just didn't compare. I'm moving all my veggies over to a new aquaponic wicking tray system.

That said, for citrus, guava and a lot of other plants, 5-1-1 is fantastic. Surprisingly, banana, sugarcane and bamboo love it. I would think they'd need more soggy mixes, but they go nuts in the stuff.

I do really want to figure out a completely inorganic mix. I'm thinking of 2-1-1 of pumice, DE and perlite. I want to use this on my big trees in pots larger than 15 gal. Any thoughts?

Hey Josh:

You're right about the cactus. I switched over to a gritty/bonsai mix of DE, perlite and pumice and they're doing a lot better, though some I just can't figure out. I have an easier time growing mandarins than a stupid cactus from Ikea, lol. I probably have 20 in this mix. The big succulents love the 5-1-1 as long as they're in large pots. My flapjack grew maybe 1 inch last year in crap soil and 18" this year so far. Same with aloe and others. I have my dragon fruit in 15 gal pot wit 5-1-1 and it loves it. In the heat, there's probably 1/2" of growth a day.

Regarding avocados, I'm not sure what's going on. I transplanted from 5 gal containers (all grafted onto mexican rootstock) into my 15 gal pots with 5-1-1. Lost 2 rare varieties which was annoying. The trees should do great in 15 gal pots, avos in 15 gals in nurseries put out fruit at that size. 30 gal pots with avocados will see dozens of fruit. But they always have commercial nursery mixes that hold a lot more water.

I'll look into the drip trays. I do have a whole drip system, but I've been fertigating with Dyna-Gro by hand. I think I might just double the watering routine since they may just need that much water. That and put them in 30 gal pots.

Then again, it could be an issue with what avocado roots like. Maybe smaller avocado seedlings in 5-1-1 work, but I'm thinking there's something incompatible about large avocado roots and the particle size of 5-1-1.

Josh,
Leave it to me to do the impossible but my cacti love MY 5-1-1 because somehow, my 5-1-1 is drier than my gritty mix, lol. Doesn't make sense to me either but overall, in repotting everything, I've found a lot less overall moisture in the way I make 5-1-1.

Since I don't have any Turface or pea gravel on hand these days, this has made me much more comfortable repotting all my succulents and the few cacti I have into 5-1-1. So far, around 6 weeks in, they seem better than before even.

Granted, overall, I still have more succulents in GM right now but I've seen no issues moving them into 5-1-1.

Or perhaps I just made all my GM wrong the whole time lol!

Jay, thanks for sharing your list. Always helpful to see what others have experienced.

I think with these mixes, it generally makes you a better gardener. I know that since using GM and 511, and seeing firsthand how little water these guys need to thrive, it helps a chronic waterer like myself to get a grip haha.

I wish I could dig out my entire backyard and fill it with 5-1-1. LOL

Hey Sugi, glad to help. I just realized I've been vastly under watering a number of plants (the avocados especially) because of how fast the 5-1-1 dries out. Now everything is looking much better.

Yes, I actually put a drip-tray under my sister's Avocado that I re-potted earlier this season. She just wouldn't water it enough, so I figured standing in water would be better than completely dying. Those big leaves transpirate a lot of moisture, though, so it has done fine.

Josh