I received my order of UV-resistant green sandbags produced by DeWitt. I thought that it would be the same polypropylene fabric that they use as a weed barrier; but I now doubt it. In other words, I expected a small hole (for water drainage) at each cross weave (the "thread" is about 1/8 to 1/12 wide, flat, and thin). Water drains quite well through the stitching at the bottom of the bag. In contrast, drainage from the fabric wall is slow. Water leakage through the fabric is best observed if a jet of water from the hose is aimed at the wall; otherwise, leakage from the wall only by gravity is slow and rare. I can't tell if the fabric has a thin film laminated coating. The surface of the fabric is smoother than I expected if there was no lamination, but more water drains out than I expected if there was a laminated coating. In no way is any possible laminated coating present on the DeWitt bag similar to that pictured for the long lasting sandbags offered by Dayton Bag Company. Making pots out of these sandbags would involve folding the bottom, and securing such folds with a few dabs hot melted glue. These would be loose folds to form a more cylindrical bottom, just strong enough to make it easier to fill the bags with dirt. UV-resistant hot glue sticks are available (I don't know where), but since these will be in the bottom of the bag, shielded from UV by dirt, sticks from the Craft section of Wal-Mart should be fine. Since such pots would be too tall given their diameter, the tops could be rolled inside out, to reduce the height. I'll go ahead and make some pots out of a few of these, since I got them anyway. But I can't really recommend them at this point: First, I doubt that any pinholes in the fabric are large enough to cause roots to branch. Second, I don't think that the oxygen diffusion rate through the bag would be that much better than a solid plastic pot. I previously suspected the first, but I was really hoping for a much improved oxygen situation. If you are currently a user of pots made from black plastic film (these have holes in the bottom, otherwise they are similar to normal plastic bags, except that they are sold as nursery pots); these DeWitt sandbags may be competitive. It is possible that if I subjected these sandbags to a small amount of wear and tear (as a transport bag), the fabric will loosen up and become more porous for oxygen. In which case, I would post an update. Here is a link that might be useful: DeWitt Sandbags

hey don.. slummin in the tree forum .... peeps .. don is a hosta freak ... and a list freak .. and i love him for both .... i will guess .. he wants to make a lists of trees ... that are favorable to garden under ... based on the aggressiveness of the root system ... and he has been to my place a few times .... go figure on that ... lol .. who knows about his choice of friends .... so what he MIGHT be looking for.. is a list of trees with tendencies toward fibrous root systems that interfere with the growth of the plants under ... but not limited to fibrous roots .... IN MY EXPERIENCE .... maple.. especially norway .. and JM [anything with acer as its first name] willow mulberry birch liquidamber [sweetgum] apple [including crab, as they sucker every time you sever a root] and now the coffee has clicked in.. and i am totally blanking.. lol ... more later.. maybe ... when i moved here and tried to get the same answers.. i was told.. by a myriad of hosta growers.. that.. IN GENERAL ... all nut trees are favorable to being deep rooted.. and allowed companion plants .. and ergo .. i went with a lot of oak ... red, scarlet,black, shingle [imbricaria??], white [bicolor?] ... and as far as my hosta peeps have said.. jugulone is not an issue under walnut ... for hosta ... absolutely no experience with live oak though ... and i had a hickory at the old house that seemed to create no problems ... all that said.. growing things under trees.. the root issue is not as important.. as watering.. as gal mentioned ... specific growing conditions ... extremely mature trees .. tend to create deserts under them ... and you need to provide the water the hosta needs ... if the plant gets the water.. then they can co-habitate in a friendly way ... but under some trees.. it is NOT going to be a plant and forget situation ... at least until the intruder achieves some level of 'establishment' ... in other words.. slap a babe in there.. and the tree might win .... as compared to inserting a mature large plant.. which can fend for itself ... or compete with the tree ... given a reasonable amount of supplemental water getting the invader ESTABLISHED ... is imperative .. for it to try to compete on a successful basis ... am i on point don???? does this help the rest of you give don extra trees for the lists ... good luck ken

With the bags the roots poke through the fibers which then constrict the outside of the roots, resulting in a sort of half-root going out into the soil. So nutrients and water are gotten from the soil but it is still possible to dig the tree up later. How thick the roots are when they encounter the fiber should have no bearing. A friend once grew eucalyptus in root bags and they grew these hilarious stub roots inside the bags that looked like fingers. The parts that extended beyond the container walls were like hairs. Independent garden centers here received assorted collector type trees including Ashe magnolia and other magnolias, Chilean fire tree etc. this week from a source that delivered them still in the root bags they were grown in. This post was edited by bboy on Fri, Mar 7, 14 at 12:05

I agree with that. I use a lot of insect screen to cover drain holes & it's very often a PITN to free it up from the root mass. Fortunately, it's usually something I can just rip right out because I'm in the process of repotting, but I've had bigger pieces of screen that I had to spend several minutes cutting free from the roots ....... and that was screen positioned to cover drain holes at the pot's bottom - how much worse might it have been if the screen was suspended several inches above the bottom? FWIW - I can't say with any degree of certainty if or how much it matters, but I don't tempt fate by using aluminum screening in my containers because I have concerns about aluminum toxicity. Aluminum becomes soluble at a pH of about 5.4, which is well within the pH range we grow in for container culture - especially since most of us use acid-forming fertilizers. Because of that bit of knowledge, reason tells me there is potential for a problem. Anecdote: when I was younger, a friend gave me a boat-shaped pot made from mill finish aluminum. I drilled a hole in it and tried to grow several different plants in it, all of which performed very poorly. Since I had never had issue growing the same plants in pots of other materials, I blamed it on the pot's composition. Al