Personally, I adjust either ratios or ingredients slightly dependent upon several factors... the type of plant, the size of the pot, the environment it will be placed in... how much time I have to dedicate to caring for my plants, etc.

The most important part of utilizing a more porous, gritty medium is understanding the concept... how it works and why you're using it. Once you fully have a grasp on the concept, and what each ingredient brings to the table, making slight adjustments to suit your own individual environment and situations will be rather easy.

If I need a little more moisture retention for a small pot, or a plant that likes things a little more moist, I make small adjustments in ingredient ratios or use a different ingredient that will hold a little more moisture for slightly longer.

For example, I have a Ledebouria that prefers a moister environment, so I've adjusted for that. I grow everything from cacti to orchids to bulbs in a rendition of the Gritty Mix, all indoors. For outdoor growing, I prefer something closer to the 511.

But I won't sacrifice the health and genetic potential for growth in the name of convenience... meaning, I won't go back to retail industry standards just so I don't have to water more often. To me, it's well worth the effort to use a medium that is healthier for the root systems... and healthy roots produce healthy plants.

There are a few growers on this forum who have lovely succulent collections... I'm sure they'll be along to add more or give you the information you seek in different terms.

Happy Growing!

Thanks for the comment.
I have read a lot of the threads, and have a decent grasp of the concept. I understand that too much fine particulate will negate the desired spacing.

What I'm specifically looking for is information about what genera might benefit from some particle sizes slightly smaller than 1/16", for water retention. I'm in central Texas, and the summer will demand more watering than I might have time/desire for.

From your experience/observations, are there genera that seem to require a more water retentive mix? I saw a thread where someone's echeverias were constantly under-watered, and they decided that the recipe needed more fine turface. I'm waiting to repot all of my stuff, but it would be nice to know if say aloes or haworthias might need a little more turface/bark.

Without making genera specific recommendations (I don't really think this can be done by anyone but you, in your environment - as it depends probably most on environment - temp/sun/humidity/airflow/wind/etc), i will comment on how to modify standard gritty mix.

Finer particles aren't necessarily the best route to greater water retention. Ideally you want the water inside particles (internal porosity, like turface or pumice has) and air in spaces between particles - fines, in addition to increasing water retention, also fill up this air space. I would never incorporate more fine turface, personally. There's a reason you spend time screening ...

Al generally recommends tuning the gritty mix by keeping bark at 1/3rd and modifying the ratio turface to grit. 1:1:1 is the same as 3:3:3, and then modify turface/grit up or down in sync so something like 4:2:3 turface:grit:bark for more water retention, or 2:4:3 turface:grit:bark for less. Keeping all particles sizes the same as you normally would.

If you already have a bunch of 1:1:1 mixed, you can just add turface or grit to taste, though this will also lower the bark fraction below 1/3rd, it's probably not a big deal.

Daniel

Absolutely adjustments to gritty mix ratios are beneficial for succulents of different types! I would say generalizing for genera is too broad. It should be customized per species (and pot size/growing area/etc. of course too).

For Crassulas, I see slightly different watering needs between C. 'Gollum', aborescens, 'Tricolor', etc. For Haworthia, I have found some variance, but not to a great degree. Really depends what you are growing.

As a side note, 1:1:1 proved to be far too water retentive for my growing environment and many of the succulent species that I grow. However, I do keep a large bucket of sifted 1:1:1 in my garage beside a bucket of pure grit. Then I can easily mix in the amount of grit desired to customize per plant (as Daniel suggested). This is normally 60-80% grit (remaining 20% turface/bark).

Overall, I just find it become easier to 'align' watering of all my plants with customized gritty for each.