Garrett,

Well, the proof is in the pudding (your seeing the good growth and all) but I would be a little careful about overfeeding them. I personally use a Miracle-Gro (10-15-10?) which is watered down to quarter-strength. That nitrogen # is a little high, IMO, but personally I like the hungry look in a plant.

Optimal fertilizer use will vary with soil mix, sun exposure, and season. Your approach certainly sounds good to me, and your plants get a bigger vote than I do.

Your regimen and mine are probably not adequate for lithops and other sensitive mesembs. Soluble, complete fertilizers which reward you with growth in Crassulaceae, Aloeaceae and most Euphorbiaceae can cause elongation and distortion in mesembs, mainly lithops. Mine definitely suffer from this problem, and I know the cause. What I don't know is an easy solution.

What I want is a lazy man's simplification to differentiate my 'fertigation' practices just enough to support my ecclectic taste in plants. Right now I'm still basically 'one-size-fits-all' except for sun exposure and some individual attention as I walk around the yard with the sprayer... and then a small area of special attention where I keep Dorstenia gigas, D lavrani, Euphorbia guillauminiana and some other prized plants.

How do you apply your fertilizer? I sometimes mix into pails and watering cans... and even hand spray bottles for sensitive plants. I also have a brass Hozon siphon mixer, but I think the concentrate intake is clogged right now with chemical buildup. Also the Hozon siphon only works with certain flow rates, so it only functions when the hose is attached to certain nozzles and not others. I have used Miracle-Gro hose-end sprayers too. I have tried Gilmour brand, but it seemed too flimsy and the spray was too weak and uneven.

I am experimenting with suggestions from a couple articles in Cactus & Succulent Journal where they advocate lowering the pH (vinegar, citric acid, or stronger stuff if you're technical) and boosting the fraction of N from ammonia versus nitrate and urea. Some have even suggested that dreaded "lush growth" which can spoil the form of cactus & succulents is more likely with urea-based fertilizers (standard Miracle Gro) than those based on ammonia (such as orchid fertilizers or "lawn shock" ammonium sulfate).

Tangentially, I also have a big, untapped compost bin. I haven't yet incorporated homemade compost into my cactus & succulent mix. Has anyone else?

DC,

No, I think that the usual sort of compost (kitchen detritus and lawn waste) doesn't go well with potted plants, but I should think a dollop of compost into PIG'd (put-in-ground) plants (as a part of the initial PIGing or as annual maintenance) isn't a bad thing, but I'd want to test it on a Crassula ovata first before I give it to the Cyphostemma uters.

Hi cactusmcharris: yes, I share your doubts.

Honestly the compost at the bottom of the bin has been sitting on the ground being eaten by worms for 2 or 3 years, so it's probably fine as a minor mix-in after modest sterilization, but even then I'd only try it as 3-5% of a container mix or 7-10% of a ground mix by volume.

And even then, as you say, I'd want to experiment with it on some rugged, disposable plants before trying it on plants I prize. Most of my agaves wouldn't care. And as you say, neither would Crassula ovata (yes, I still grow some... sentimental reasons I guess).