I'm just musing here & not being snippy, but I think that the 5:1:1 mix performs significantly better than peat based soils, and remains structurally sound much longer (4-5 times longer, based on all other cultural conditions being equal). The gritty mix is even better, providing greater aeration and lasting indefinitely. I'm not saying that to promote what others refer to as 'Al's Soils', only to illustrate that soils that are highly aerated and structurally stable are much preferred to peat/coir/compost-based soils for the results oriented crowd. I'm able to say this based on the hundreds of people at GW and other sites that are using these soils and some fertilizer recommendations with a degree of success that has them saying they left soils like MG or other peat-based soils and will never look back. There is a crowd that wants to make things easier (these soils are much more forgiving and easier to grow in) and appreciates the idea that their plants are growing at closer to their genetic potential. Then, there is the group that feels that what they are using is 'good enough'. I have no quarrel with how folks establish their priorities, but what I usually hear, and what I'm hearing above is 'it's too much bother'. I never try to coax anyone to use "my" soils. I only point out the considerable benefits of higher aeration and greater durability and let others decide. I respect your decisions, but at the same time I can point to the fact that what's easier for the grower and what's better for the plant are often mutually exclusive. In this case, there is an inverse relationship between effort and results, but it's not as great as it seems. Yes, there is some effort involved in finding the ingredients and making the soil, but part of that effort is negated in the fact that healthier roots make healthier plants and healthy plants are less susceptible to insects and disease, and are more productive or prolific. Include the fact that root rot and soluble salts accumulation (especially for houseplants) is something you would have to work at to achieve, and you've got a pretty good case for abandoning the heavy soils. In the end, it always almost always distills to an individual decision. Is the perceived gain worth the perceived effort. Some answer with a resounding yes, and others are not so sure or unwilling to go through the trouble. I respect any one's decision because my part in trying to help folks ends with trying to provide the best science I can so they can make up their own minds. However, if the soils didn't work considerably better than conventional soils, I'd have been handed my head long ago. ;o) Take care. Al

@Nil13 made reference to the Whitcomb 311 mix, which is an earlier historical attempt to create a more coarse potting soil for container plants. I think it is extremely helpful to read a document written by Carl Whitcomb that explains how he came on this formula by accident. Essentially what happened is he accidentally left nine test pots under a bench and everyone forgot they were there. They had successfully nearly killed all of their test plants by watering in a normal potting soil mix and the unwatered plants started to do very well. What I have started to realize is that any plant can do well in many different soil mixes, if you are able to carefully control the watering. This explains why so many people on this forum claim gritty mix is not as good for their succulents as their (fill in some random horrible soil with lots of small particles) mix. Inevitably those people are growing their plants indoors. They have enormous experience with their plant type and they know exactly when to water the plant. So that is the case of a very skilled gardener compensating for a very bad soil. What gritty mix does for me is let me grow succulents outside in very abusive weather conditions, without the plant dying. A plant can get a week of rain and it will still drain well. During Summer, gritty mix will tolerate a bit of overwatering, although you still really need to pay attention to not overwatering. Whether you make your 511 mix with perlite/peat, or with two parts Turface, or with lava and pumice, is probably in the big picture not going to be the deciding factor in whether your plants grow well or not. Success can be add with any of those mixes because the size of the particles allows the roots to breathe and prevents capillary action of water from bring the perched water table to the top of the pot and drowning the roots. Fine-tuning how you make 511 is a question of matching the plant type to the moisture retention of the soil and to the watering habit and climate exposure. Any 511 variant is going to do better than almost any commercial potting soil because of the larger particles used in the majority of the mix.

Hi everyone, I've read Al's posts on soil structure and the Perched Water Table for a long time, and finally decided to invest the time, effort and $$ to try them. But, I have one question. We all know/heard/read that "particle size matters", which is why we don't add peat to gritty mix, for example - so we don't end up with "pudding". So here is my question: If one were to mix gritty mix with some slightly larger ingredients (say, unscreened Repti-Bark and similar sized LECA/hydroton/clay balls in lieu of Turface) with grower size Manna Pro Grit, would the Grit (it's size, specifically) act as a lowest common denominator in determining aeration/draining? In other words, would aeration/drainage be significantly worse in such a mix than in the traditional Gritty Mix where all ingredients are screened to the size of the grit? If the smallest particle is the screened Grit, this would not result in "pudding" when it's mixed with slightly larger particles as described above, correct? Thank you!

Yes, and using mixes specifically for 'potted' plants can be quite tricky to say the least. A balancing act too that is one does not master, your growing experience can be quite limited or very rewarding. For me it's all about sacrifice's, sacrifices made in order to attain the best possible growing experience possible without sacrificing the integrity of the mix and the vitality of my trees and their root systems. One has to be able to foresee any potential issues before deciding what to use. What might do a great job in the 'summer' might be the death of your trees in the 'winter' months. For instance: One could use a mix that hold much more water for the summer while in the end could kill your trees holding too much water come the winter and shorter days. One could use a mix that holds PWT that can be used to your advantage and disadvantage if it rains too much, stays cold for long periods of time, or gets worst as the mix break down. One could use a mix that dried out very rapidly, almost too fast for the summer and in the winter and then in summer loose their trees to not enough moisture. One could also use a mix in which you have to check the moisture levels quite often in each and every pot, for some hundreds, or use a mix that you can water every time you water for all at once without fear of root rot without having to check to see if they need water. The 511 to me is a good balance. You can add just enough smaller particles to keep the soil mix moist longer in summer while reasonably dry out in the winter in a good amount of time. You can use it on all your plants and water all your plants at the same time whether they are still moist or not. The 511 also allows you to store your trees at very cold temps, even though the pots are still moist without fear of rot. The 511 also dries out evenly and holds its structure much longer than peat or fine particle based mixes.. So If I were to match up the 'pros' with the 'cons'. I'd say the 'pros' far outweigh using a 511 mix or the like in my favor. It might be a great idea for each of us to decide what you are willing to sacrifice in the winter or the summer and find a happy medium that will work for ALL seasons to save yourself a lot of headache and certain trees their demise. What is forgiving in the summer time or in a nice warm brightly lit greenhouse structure might not bode so well for trees in less than ideal conditions come shorter colder wintery days indoors. MIke