I know I'll probably take a hit for this, but I'll stand firm on my assertion that the mix of equal parts of peat, black soil, sand, and perlite is a poor choice for houseplants - especially for inexperienced waterers. We can actually quantify what makes a good container soil, as noted above. Aeration is KEY in container soils and this mix WILL compact and WILL NOT hold enough air for an extremely high % of plants to ever grow at or even near their potential genetic vigor. I'm the first to say that it doesn't matter what soils are actually made of, as long as they provide anchoring, nutrient and water-holding ability, and most importantly - they must hold an ample volume of air and allow gas exchange at the rootzone. The soil described above will lack aeration and adequate gas exchange. That a particular person does something for a number of years with results that are acceptable, doesn't mean it should be adopted by others. Saying, "It works for me" is simply a statement and should not be regarded as a clarion call that others should follow blindly. That's all I have to say, and it's just an opinion, but it's easily supported by science and practical experience, and can be corroborated by dozens, if not hundreds of folks I've helped with soil problems over the years. I'm not trying to stir the pot here, just trying to help folks see that there are better choices than the mix we're discussing. Use science, don't fight against it. (I wish someone famous would have said that so I could offer it as a quote & it would carry more weight) ;o) A friend of mine, Joe Pye, comes to mind as I consider the reasoning of some. Joe Pye would get up every morning before work and bang his head against the wall. He always said it worked for him. One day he got tired of banging his head and decided to change, so he kissed his wife goodbye instead. Joe never did go back to banging his head. Moral: If your happy with how things are growing, please maintain the status quo, but at least allow there just might be a better way. Al

Greenman: You are so right on..It never worked for me in the past..I never knew why until I read some fascinating articles from a very knowledgeable man.. This is an excert from a wonderful thread. RE: Container Soils - Water Movement & Retention XII clip this post email this post what is this? see most clipped and recent clippings Posted by tapla z5b-6a MI (My Page) on Fri, Nov 19, 10 at 15:10 Todd - most of the people that participate on this thread are interested in improving on the results and minimizing the problems so often encountered when using peat-based commercially prepared soils; others are satisfied with the results they get from these soils and have no interest in changing anything, which is absolutely fine. I've been offered a good opportunity to explain something about the (lack of) efficacy in trying to amend heavy bagged soils by adding some perlite, so I'll expound a little, basing what I offer on science and my own practical experience. Perlite doesn't change the drainage characteristics of a soil or the height of the PWT. To visualize this, think of how well a pot full of BBs would drain (perlite), then think of how poorly a pot full of pudding would drain (bagged soil). Even mixing the pudding and BBs together 1:1 in a third pot yields a mix that retains the drainage characteristics and PWT height of the pudding. It's only after the BBs become the largest fraction of the mix (60-75%) that drainage & PWT height begins to improve. You cannot add coarse material to fine material and improve drainage & the ht of the PWT. Use the same example as above & replace the pudding with play sand or peat moss - same results. The benefit in adding perlite to heavy soils doesn't come from the fact that they drain better. The fine peat or pudding particles simply 'fill in' around the perlite, so drainage & the ht of the PWT remains the same. All perlite does in heavy soils is occupy space that would otherwise be full of water. Perlite simply reduces the amount of water a soil is capable of holding because it is not internally porous. IOW - all it does is take up space. If you want to profit from a soil that offers superior drainage and aeration, you need to build it into the soil from the start, by ensuring that the soil is primarily comprised of particles much larger than those in peat/compost/coir, which is why the recipes I suggest as starting points all direct readers to START with the foremost fraction of the soil being large particles, to ensure excellent aeration. From there, if you choose, you can add an appropriate volume of finer particles to increase water retention. You do not have that option with a soil that is already extremely water-retentive right out of the bag. Al

Rick, are you sure you are not incorrectly using the term "genotype" more as what a "phenotype" is? The genotype is the complete genetic material--whether expressed or not. The phenotype is what is actually expressed. I am also not sure if you are familiar with "ecotype" either. Although I agree with your comment about genetic adaptation taking time, the Fraxinus example can still be problematic in that regionally, a gene for cold hardiness for the tree may not be typically expressed in Georgia populations, and thus would perish in Minnesota. Although the gene IS in the Georgia ash trees, it can be turned off in that population (an ecotype); and thus, if a tree in Georgia was moved to MInnesota, it is quite possible it would perish if that specific tree does not have the gene completely turned on to create the proteins, blah blah to ensure harsher winter survival ability. A terrific example of the ecotype is Acer rubrum. A FLorida native ACer rubrum will FAIL survival in a MInnesota and a MN native Acer rubrum will perish if planted in Florida. Same genotype, different phenotype (as a definite ecotype within the species). In another example, it is recommended to not secure woody plant materials far out of your cold hardiness range. Every plant in a species is similar, but still has terrific genetic variation possibilities. Forsythias, for example, grow in a nursery in Tennessee may not have the same caliber of cold hardiness all across the number of plants. If there are 10 forsythia plants at a nursery in Nashville, they will all survive that zone 7 winter, but, it is very possible that 3 of those forsythias do not have the "cold hardiness gene for survival below -10", and thus, those particular plants WOULD perish in Minnesota, but still survive in Tennessee. If these 10 plants always grew in Tennesee, one would never know which truly was the hardy since they would not be naturally selected/killed off by an unlike -10 event there. In Human Terms--we all have hte SAME GENOTYPE (except those with true genetic abnormalities such as XXY, XO, etc), but the PHENOTYPE is different. The phenotype is what is physically expressed. I can guarantee that I have the same 99.99% genetic code in me as anyone on this board; BUT I likely will have some expressed gene here and there that will predispose me to a certain medical/deliterious condition as someone else may be totally protected from it because their code is expressed in their body so that they are immune. I also recall much uncertainty in human genetics from university coursework about the simple "genotype" as you put it, regarding the races. We all have the code to be very darked skinned or havea different shaped eye, etc. It's through developmental factors by the genes of hte parents, perhaps selected through adaptations that the PHYSICAL (phenotype)is different, but the genotype (the inherihent code of that species) is the same. Perhaps we are making the same point but with a different perspective. I even am confused now with my point--am I supporting your comment now or acutally arguing against it! ;) I didn't read your paper, it sounds as if it's conifer genetics. My point is the use of genotype versus phenotype (which I think you made a personal definition) and also the reality of ecotypes.

Bernd, I learned something about Fire and Ice...I'm on my second (in its third year) and it's looking positive. I actually think it does better in a pot than planted in the ground!!! At least here anyway. My first one came up the first spring as a "mini" and took forever to grow at all. I gave it to a relative, lol. ;-). I have never planted this one and last year it was especially superb...I posted pics whenever I got the chance! Even last September it looked fab. No melt-out, nada... just a very happy hosta, in an ugly black nursery pot, getting sun exposure until about 2:00 here in zone 5. Just wanted to share that with you, for what it's worth. Edited to add:. still in ugly pot, purple pips just starting to poke through... I forgot to bring it into the sunlight until just yesterday. It was over wintered on the northwest corner of the house. Think maybe I'll spiffy up the pot by placing it inside a nicer one! It deserves it. Newsflash...you'll never believe it! I just went to check on the number of pips on it and I'm ashamed to tell you that the potting media is the pits! There is gravel and dirt in that pot...no wonder I had to use both arms to lift it!!! Two winters ago when I was potting I ran out of mix and used dirt and some gravel. I lost a piece of my Frances Williams (rotted) but F&I was fine. I had better repot it before I lose it! Duh!