When it comes to root health, pots with gas permeable walls carry the day. Terra cotta clay pots are better than plastic or vitrified clay pots and fabric pots are better than terra cotta clay. The reason is greater gas exchange through container walls and the fact that an increase in gas exchange comes with an increase in evaporative water loss, which can be a lifesaver when using water retentive media. There will still be a PWT in these pots, and for any given medium it will the same ht in a pot with rigid sides as in the fabric or air pots at container capacity. Container capacity is a measure of how much water the grow medium in a pot or container holds at the moment it has stopped draining after having been watered to the point of complete saturation. The ht of the PWT and how long it affects root function is usually key/critical in determining what opportunity a plant will have to realize as much of its genetic potential as possible (within the limiting effects of other cultural influences). The factor that most affects the ht of a PWT is the size of the particles from which the medium is made. So, reducing the duration of PWTs limitations increases the opportunity for plants to realize a greater measure of their genetic potential. But wait! There's a more important consideration. If you place your fabric containers directly on the ground/soil, from the perspective of hydrology it changes the fabric container to a raised bed; this, because water is free to move through the fabric between the grow medium and the earth, with the earth acting as a giant wick. This means, because of the increase in the force of adhesion in the mineral soil beneath the pot (due to a mineral soils much larger o/a surface area on a per volume basis), water in the soil will be pulled downward with enough source to overcome the capillarity holding it perched in the container. As long as you don't place the fabric container on coarse sand, peastone, or other large particles, the earth will likely pull all perched water from most media one is likely to use in a container. I've mentioned this and the fact that healing in your pots situating them directly on top of soil turns them into raised beds. the only caveat being it's essential that there is a 'soil bridge' so there is continuity of the soil column between the soil (earth) and the grow medium in the container, through the drain hole(s), so water doesn't have to jump an air gap to exit the container. This applies more to pots with rigid walls and is not a factor when discussing fabric containers. Al

You're welcome. Thanks again, for being so kind. Some thoughts I offered in another, older threads on this forum. They should pretty much answer your question, and may even be quoted in the text somewhere up this thread (if so, I apologize for the redundancy): In my estimation, the only case to be made for reusing container soils is one of economics, and you'll never find me argue against making that decision. If you can't afford, you can't afford it. That said and setting economics aside, you might decide to reuse soil for reasons other than economical. Perhaps the effort involved with acquiring (or making your own) soil is something you might not wish to go through or be bothered with. In any case, it would be difficult to show that soils in a more advanced state of structural collapse can somehow be preferred to a soil that can be counted on to maintain its structure for the entire growth cycle. So, if the economic aspect is set aside, at some point you must decide that "my used soil is good enough" and that you're willing to accept whatever the results of that decision are. All soils are not created equal. The soils I grow in are usually pine bark based & collapse structurally at a much slower rate that peat based soils, yet I usually choose to turn them into the garden or give them over to a compost pile where they serve a better purpose than as a container soil after a year of service. Some plantings (like woody materials and some perennials) do pretty well the second year in the same bark-based soil, and with careful watering, I'm usually able to get them through a third year w/o root issues. Watering habits are an extremely important part of container gardening. Well structured soils that drain well are much more forgiving and certainly favor success on the part of the more inexperienced gardeners. As soils age, water retention increases and growing becomes increasingly difficult. If your (anyone's) excellence in watering skills allows you to grow in an aging medium, or if your decision that "good enough" is good enough for you, then it's (your decision) is good enough for me, too. The phrases "it works for me" or "I've done it this way for years w/o problems" is often offered up as good reason to continue the status quo, but there's not much substance there. I'm being called away now, but I'll leave with something I offered in reply on a recent thread: "... First, plants really aren't particular about what soil is made of. As long as you're willing to stand over your plant & water every 10 minutes, you can grow most plants perfectly well in a bucket of marbles. Mix a little of the proper fertilizers in the water & you're good to go. The plant has all it needs - water, nutrients, air in the root zone, and something to hold it in place. So, if we can grow in marbles, how can a soil fail? Our growing skills fail us more often than our soils fail. We often lack the experience or knowledge to recognize the shortcomings of our soils and to adjust for them. The lower our experience/knowledge levels are, the more nearly perfect should be the soils we grow in, but this is a catch 22 situation because hidden in the inexperience is the inability to even recognize differences between good and bad soil(s). Container soils fail when their structure fails. When we select soils with components that break down quickly or that are so small they find their way into and clog macro-pores, we begin our growing attempts under a handicap. I see anecdotes about reusing soils, even recommendations to do it all over these forums. I don't argue with the practice, but I (very) rarely do it, even when growing flowery annuals, meant only for a single season. Soils don't break down at an even rate. If you assign a soil a life of two years and imagine that the soil goes from perfect to unusable in that time, it's likely it would be fine for the first year, lose about 25% of its suitability in the first half of the second year, and lose the other 75% in the last half of the second year. This is an approximation & is only meant to illustrate the exponential rate at which soils collapse. Soils that are suitable for only a growing season show a similar rate of decline, but at an accelerated rate. When a used soil is mixed with fresh soil after a growing season, the old soil particles are in or about to begin a period of accelerated decay. I choose to turn them into the garden or they find their way to a compost pile. Unless the reasons are economical, I find it difficult to imagine why anyone would add garden soils to container soils. It destroys aeration and usually causes soils to retain too much water for too long. Sand (unless approaching the size of BB's), has the same effect. I don't use compost in soils because of the negative effect on aeration/drainage. The small amount of micro-nutrients provided by compost can be more efficiently added, organically or inorganically, via other vehicles. To boil this all down, a container soil fails when the inverse relationship between aeration/drainage goes awry. When aeration is reduced, soggy soil is the result, and trouble is in the making. I've mentioned before that I don't post here to get people to convert to a particular mix or blend of soil. I post what I know will work very well for anyone who can get appropriate ingredients & modify the mix to suit their climate & other cultural conditions. If you use a mix that guarantees good aeration for the expected life of the planting - you're in good shape. Most peat based mixes will not work well in extended life plantings. Conifer bark based mixes, on the other hand, retain structure for much longer periods. If you still have questions, please don't hesitate .... Al

Regarding Turface fines, do I understand correctly that they would be helpful for in-ground trees in flat or otherwise insufficiently drained areas? I do have some trees like that and would love to put the Turface fines to good use. It depends on what the soil is like and whether or not they are used in a raised bed. If you have an area with heavy clay and you incorporate them into the soil, they might actually increase the amount of water that collects in the soil surrounding your plants' roots. This is known as the "bathtub effect". Amending a garden where the soil is clay just causes the garden area to hold more water unless the garden is on a slope or there are tiles or a ditch to direct water away from the area. THEN, it can be very helpful. Whenever there is an area where percolation of water through the soil is slow, amending it in the hope of creating more air space results in an additional measure of water filling the newly created pores until the water naturally percolates through the soil. In the case where they are used in a raised bed (RB), water will move horizontally away from the RB across the top of the clay soil, where it will evaporate much faster than water below the surface of soils not exposed to air movement. When water evaporates from the surface of the surrounding soil, it 'pulls' additional water from RBs via capillary action. That's why clay soils below RBs should not be amended with organic material or sand as it creates thew bathtub effect and holds more water in the amended areas unless there is a plan in place to direct subsurface water away from the area. I couldn’t seem to locate uncomposted pine or fir bark fines ........ Will exceeding 3/8” on the bark fines be a big problem for the gritty mix? April through Memorial Day is the easiest time of year to find good bark products for making media. I suggest that you should until you find the right ingredients to make either the 5:1:1 mix or the gritty mix; this, because if you 'try to make something work', there is a good chance you'll end up unimpressed and give up. If you get it right the first time, it will be a game changer. Too, once you find a supplier, keep looking for other suppliers. I've found I can always find it somewhere near me, but operations go out of business or might decide to stop carrying a product some of us find very useful. What I'm saying is, it's better to have more than one basket to put your eggs in. I'm on my last bag of fir bark screened 1/8-1/4, so I'll be needing to screen bark again come next spring. Also, do you prefer/recommend gypsum or Foliage Pro 9-3-6 more for trees in pots? Your fertilizer will dictate what liming agent is appropriate. I always lime the 5:1:1 mix with dolomitic (garden lime) to bring the pH up to a more acceptable level. If I'm using the gritty mix + Foliage-Pro 9-3-6, there is no need to use a liming agent. If I'm using the gritty mix and a fertilizer without calcium or magnesium, I'll use gypsum (CaSO4) as a calcium source and Epsom salts (MgSO4) as a source of magnesium as neither compound has an appreciable effect on pH. Note: I haven't had to supplement Ca/Mg for a long time - since I started using Foliage-Pro 9-3-6. If someone asked me what hort product I would consider to be the most indispensable, it would be the FP 9-3-6. Al

I think the peat moss content was mentioned as an example of a more moist soil, not as a request for more info about peat moss. In any case, garden plants that aren't so sensitive to more dry conditions are usually called xeric or drought tolerant. There are far fewer of those than the usual collection of thirsty garden plants, but that is probably the result of where one lives/shops. It would be difficult to cultivate truly xeric full sun plants where I am because a normal summer includes plenty of rain. But the opposite may not be as much of a thing because if one wants to spend time watering, it would be much easier to keep thirsty plants alive in a dry location. It's usually easy to add a condition, like more water, more heat, additional lighting, but virtually impossible to remove one, such as too much water or too much heat. From what I've seen of the plants I've had, unless the roots actually rot (overwatering,) few plants thrive if they are in a pot and the soil literally dries all the way, regardless of soil type. Being able to survive a drought does not mean that a plant will continue to look like it is thriving. Plants that survive near-death experiences usually look like survivors, not thrivers. Generally, the more water a plant needs the larger leaves it has. The most xeric plants don't have any leaves at all, or they are only grown by the plant during a moist spell. If one wants to water less often, I would recommend bigger pots, putting pots in less sun, using very light color pots if they will have the sun shining on then while it's hot, making the effort to setup drip watering if applicable, &/or temporarily grounding non-woody entities for those who live where it rains relatively often so mother nature can do some of the work. There is nothing inherently superior about one condition or style of care than another. Once you have a working comprehension that is realistic & honest about the conditions and care you have available to offer, it's not usually difficult to find way too many plants that would thrive in those circumstances.