I'm not sure if it's root structure, so much.

I have not used Gritty Mix yet, that's a Spring 2015 project - I just dove into 5-1-1 this year.

I do wonder if plants with very high water requirements (bog plants in particular) would do poorly in the gritty mix.

From what I have seen here, woodies in general do very well in it, as do succulents.

That said, I'm sure you can modify it quite a bit - more bark for plants that need more moisture, less for something that likes it dry...

Al and others will hopefully chime in, as I'm curious myself.

I have Hydrangea in gritty mix and it does just fine. Not a bog plant but one that respires away a lot of water, which is fine as long as the water is replaced as often as needed. The difference in the water requirements are dramatic as the temperature and relative humidity vary. Al

Based on Al's note above, and my own experience, the main reason to use 5-1-1 over Gritty mix is convenience. If you source the correct ingredients for 5-1-1, it's quite cheap and easy to make. Gritty takes more effort, with most or all components requiring screening at least once if not twice. Gritty is also much heavier, especially when wet.

Gritty is designed for long term durability (it won't compact, and can be reused), and 5-1-1 is designed for single season use, though some people use it for 2 seasons without running into big problems. Most plants in containers really benefit from bare-rooting/repotting every year or two anyway. I normally never re-use 5-1-1 no matter how fresh it is - when repotting I discard it. But I might leave a plant in the same batch for 2 seasons (my convenience, not the plants), though I prefer not to.

You can modify both Gritty and 5-1-1 with respect to water retention - see Al's epic Water Movement in Containers thread (the classic gritty/5-1-1 thesis) for suggestions on how to do this.

I personally use Gritty mix for smaller, mostly indoor plants. I use 5-1-1 for a majority of my outdoor plants, a combination of woody and non-woody, perennial and annual. Almost all of my outdoor pots are much larger than my indoor pots. My larger indoor containers also get 5-1-1.

All plants I've tried to grow in both seem to like either mix, with proper watering. If cost/effort was the same, I'd probably use Gritty for a lot more plants, but at least in my case, it is very different.

Thank you all so very much! Such a wonderful write up and advice, I wish there was an easy way to catalog all these thoughts and advice!

I thought Al was tapla, is this a new user name?

I will continue to use and learn both mixes, I do have issues where I'm away for work and my wife unfortunately doesn't have as much a green thumb.

One issue you may be able to help me with: I cannot seem to find a way to keep my maidenhair fern happy. I try keeping the rootball moist. Right now it's in 5:1:1 and I haven't seen it more unhappy. Does anyone have Maidenhair experience?

Living in the hot, dry desert, I can't use Gritty outside for much of anything from April to Oct. I love it indoors for cacti and sux though.

Pots with Gritty can also get impossibly heavy very quick when assembling. That nice little succulent tray now weighs 50 lbs!

There are a few plants that Al has specified to put into 5-1-1 rather than Gritty, such as Scilla. I also pot Christmas Cacti and other jungle cacti, orchids, and hoyas in 5-1-1 instead of Gritty. With my habits, I find that they just do better.

Josh

Al is Tapla... with Tapla being his member name, here. We've just taken to calling him Al. :-)

The link below, containing Al's original article, is the best piece of information there is to read. I copied it and pasted it to my desktop long ago... before it reached such a high number of repeat postings. The information and recipes contained within it are indispensable, in my opinion.

I've read and reread it over the years so many times... which has helped me to remember the most important points.

And from the information, I've built my own renditions of the mixes that work best for the ingredients I'm able to source locally, and that work for my own individual growing needs.

Here is a link that might be useful: Container Soils - Water Movement and Retention XX

Thank you, I think it's time for a re-read!

Don't use the griity mix if you don't know how to use it..

MIke