Hi, rina. I know wood chips are different than bark, but I saw a nursery that was using these mixed with some alder saw dust. In about a year it turned to this incredible black, rich "soil". The guy as the nursery said it breaks down better and more nutritious for the soil and depletes less nitrogen in the process. The wood chips I was seeking are about the size of medium bark in nurseries. In retrospect, I am glad I didn't try that. Works great outdoors, not sure about containers! The black bark is essentially composted evergreen tree bark. I say evergreen because it could be a mix of a number of different types here in the Pacific NW --- hemlock, fir, ceder, spruce, etc. I didn't screen it, it seemed plenty loose initially; small to medium size in comparison to bagged nursery store bark. It would have been o.k. had I added the peat and perlite per the formulas given here. Screening would have left just the larger pieces, but that would be quite a chore for the volume I was using! I repotted some of the plants using the 5:1:1 formula with my black bark and those are doing much, much, better. A gardening friend said "Think of it...bark is like big saw dust. If you pack it down it gets as hard as a board". That is essentially what happened when I used the black bark alone without the the perlite and moss. ;(

Exactly, the paper i pasted from describes the same phenom you have been describing for over 10 years. I have always raged that the big greenhouse media suppliers claim that 30% perlite into a peat is a high porosity mix. And so many growers prefer short squatty containers [helpful for blow over prevention but nothing else] Container Geometry is almost as important as the mix. i remember in 1984 I took a 400 level greenhouse management course at University of Delaware. The prof soaked a rectangular sponge and held it by the edges parrallel to the sink flatwise and let water drain, then he rotated the sponge on the shorter vertical axis and more water drained, when that free drainage ended he then rotated the sponge vertically in it tallest plane and more water drained. When I read your suggestion about using a draping shoelace as draining wick to lower the PWT the distance of the wick, I shouted YES at the elegant simple brilliance. In 1977 I grew a marijuana plant in a milk crate full of gravel, the stalk was over 2 inches in diameter [no different than growing in glass.] BTW, in your gritty mix what are the ratios and actual particle size for each component? I would think to use slightly larger particle sizes than i think you were using and i would probably consider using zeolite or a calcined DE or calcined clay. BTW, Ep minerals makes several absorbents both DE and Clay, Calcined or regular as various spill absorbers available in any auto parts store. 5o pounds for about 10 dollars. Don''t know the particle sizes but likely need to be screened to eliminate the fines. The clays are generally calcium bentonite and not sodium bentonite so less sodium and less swelling. I beileve Arcillite and Tuface are calcium bentonites. I was just thinking that decomoposed granite and even bark add no water holding capacity but with DE and Proper sized ceramics you could add more waterholding capacity but still maintain the airspace. The airspace in the ep mineral clay was pretty low when I measured it last, but I did not screen it. Somewhere I have a spreadsheet with AFP, WHC, TP, TPv, etc for over a dozen components and mixes. I have run quite a few in both 16 oz and taller 32 oz cups, [1 liter exactly when filled to rim overflow which makes that size intuitively easy for all the math. I think i found your posts about 3 years ago and then lost them. Am I correct in thinking you have some water release curve data around somewhere. Someone posted some WRC showing that Axis DE or perhaps the Axis clay media held huge amounts of water but easily released over 75% to the plant. TI can not find that post. I was actually searching for Vertical hydraulic conductivity, Capillary Rise and Capillary rate and wicking when your links showed up. The axis DE is like $90 a bag for 50 pounds so i think I could more cheaply reproduce from other products but have to screen. where I live in idaho, there is a Celatom DE plant less than 60 miles away, 2 zeolite mines, a sodium bentonite mine, WHC and Airspace mid 20s in the 2 larger particle sizess. Also the best white pumice [Hess] source mine a few hours away. I had hoped better water holding capacity. I plan on rerunning all the mixes again in a few months now that i have more standardized my process using multiple cup sizes, some of them tamped or shaken to settle, some top watered, some bottom water, measure distance of subsidence if any. I also have a vegetronix tensionometer now and will take additional measures at various depths to measure the exact tension and also verify depth of pWT which i can usually see through the transparent cups if I use a marking dye and saturate from below. Anyway I will share those spreadsheets in the near future If i were to guess, you have some sort of plant and soil science background or some civil engineering background and a love for plants. At any rate, your explanations and examples are some of the best I have ever come across, and your shoelace suggestion is brilliant, truly. i read so much WRONG advice or the wrong analysis for reason why something works or does not work. it is refreshing to come across accurate information Garret Goyette

Hi, Just curious, I have a question about sphagnum peat vs sphagnum moss. By mistake, I purchased sphagnum moss at the onset of making the 511 mix. I mixed one batch and used it for one of my 3 plants. When I realized that I was using the moss instead of the sphagnum peat, I threw it out and purchased the correct one and used it to make the mix for the other 2 plants I have. My question is this, is it possible that the presence of the sphagnum moss in this one container could somehow attract any pests? The reason I ask is that I saw about a couple of black, winged, fast-moving pests (maybe thrips or gnats?) around this plant today. Upon further inspection, I shuffled some of the top mix and saw a single, tiny larva(e) crawling in the medium and suspected that I have pests breeding in my container. And afterwards, as I shook the container, a fast crawling, winged pest climbed out of the mix, and up the side of the container. I sprayed this plant with some insecticdal soap and plan on repotting it using the sphagnum peat moss instead. So could this (sphagnum moss) be the reason for pest-sightings? I want to solve a potential big problem now, before the real bug season begins. By the way, I haven't watered this plant for like a week and it still seems to be moist inside. I had watered every 3 days prior to the last time.

Thank you both for your feed back it's much appreciated. Beach barbie, I do move the trays regularly by default- my cat keeps drinking the water, even though she always has a fresh bowl available. And I do think it's a tropical variety. BTW I love your name, it creates a warm image. Watergal, I don't see any evidence of pests, but your comment concerned me so I sprayed the entire plant with insecticidal soap just to be sure. On the under side of the foliage I do see some VERY TINY white powder like specs that rub off with the finger, too small for aphids. Any idea what that may be? And am I on target for March to expect new buds. Thanks, Happy Valentines Day..