Container Soils - Water Movement & Retention IX
tapla (mid-Michigan, USDA z5b-6a)
14 years ago
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katskan41
14 years agolast modified: 9 years agolathyrus_odoratus
14 years agolast modified: 9 years agoRelated Discussions
orchid mix for fir bark
Comments (11)sorry i didn't clarify. i'm using the orchid fir bark to for my blueberry bush. i only bought the orchid mix because i couldn't find fir bark anywhere else. It should work fine, but is larger than ideal. All this means is you will need to water a bit more often. If you are OK with that, all is well. When it comes to particle size, it's not just about the length/width, it is also about how the individual particles pack together. Lack of uniformity in shape is desirable and this results in particles that have difficulty compressing together and thus open air spaces result. Jane says: Different size bark or stone leaves large air spaces. Most orchid roots would rot if buried in any type gritty or soil mix. Different sizes do not necessarily leave large air spaces. Different shapes do. If we were to take particles where half were 1/8th inch squares and the rest were 1" squares they would eventually compact to make a solid block. The smaller squares would simply fill in the spaces between any larger squares. If our shapes are squares, circles, triangles and etc. then they have a very hard time fitting together like puzzle pieces and sealing up air passageways. The mean size of the particles is important, but once that size is achieved it's more important to have irregular shapes than shapes capable of fitting together and filling in those air spaces....See MoreContainer Soils - Water Movement and Retention XVII
Comments (202)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...See MoreSoil, Watering, Fertilizer and questions for Al (tapla)
Comments (24)Finally I got all the ingredients for the gritty mix, to my surprise, the hardest to find is the pine bark fine(I still did not find it). I am using the Repti Bark for now (a little pricy -$19.99 for a 24 quart bag). But do not want to wait any more, will use Repti Bark for now whereas keep looking for I Pine bark fines. Well, I have to say the particle size of Turface and Gran-I-Grit is smaller than I thought although I saw so many pictures on GW. I still do not have Foliage Pro 9-3-6, But I got Osmocote Outdoor & Indoor plant food. The ratio is 19-6-12 ( close to 9-3-6), is that ok for now (Will order Foliage Pro from internet later. I got some Jade Plant, Christmas Cactus, Spider Plant and Some NOID succulents cuttings before I found all the ingredients. I put them in the Miracle Grow Potting Mix and they rooted already. But like most people find out already, the bagged potting mix is so hard to water when it drys - the water just stay on the top of the soil. I was repotting them (except the spider plant) into the new gritty mix this afternoon. I did not even screen the Turface and Gran-I-Grit as I have not gotten the hardware cloth to make the filter yet. But I did shake the bag before I opened the Turface to hope the smaller particles will fall to the bottom. This is how it looks after I mix the three ingredients. Follow the tradition, a dime in the center Then put the mix and Osmocote into a soaked pot, water it well until water come out from the drainage hole. Soak the cutting that grown in the bagged potting mix, Remove most of the soil from the root - but not all - intimated by afraid broke the root. Put the plant into the gritty mix. It is actually hard to make a proper hole to put the roots in - the gritty mix is heavy so they keep falling into the hole you make for the roots. Final results: How do they look? Am I doing it right. I also have some Spider plant rooted, not sure is gritty mix good for them too. I had the impression that gritty mix is very good for woody plant, but Spider plant is somewhat herb? Should I put them in 5:1:1 mix. (I do not think I will make 5:1:1 mix though, since pine bark fines are not available and Repti bark is pricy). Also, Does anybody know the ID for the two plants on the last picture (the one that not Christmas Cactus or Jade Plant) And if anybody knows where to find pine bark fines in new England area, please let me know. Thanks....See MoreCONTAINER SOILS - WATER MOVEMENT and RETENTION XXII
Comments (1044)Over the years, I've saved a ton of word documents that answer common questions. One of those documents is about particle size: Particle Sizes (ideal) In a perfect world, the mineral fraction for use in the gritty mix would range in size from 1/10 - 5/32" (.100 - .156", or 2.5 - 4.0mm). The bark fraction would be slightly larger to allow for some breakdown over the life of the planting ........ from 1/8 - 1/4 is about ideal (.125 - .250" or 3.25 - 6.25mm). For the 5:1:1 mix, particle size should be from dust to 3/8". (0 - .375", or 0 - 4mm), with most of the bark ranging in size from 3/16 - 3/8" ( .188 - .375", or 4.8 - 9.5mm). The perlite should be on the coarse side - something like the all purpose or super coarse shown below. If you read the size gradation next to the images, you'll see the images are misleading as the product appears to be much larger than the size listed in print. starter: 1/16 - 3/32 inch (1.6 - 2.4mm) you can sub #1 cherrystone/quartzite if available grower: 3/32 - 3/16 inch (2.4 - 4.8mm) you can sub #2 cherrystone/quartzite if available developer: 3/16 - 5/16 (4.8 - 8.0mm) you can sub #3 cherrystone/quartzite if available turkey: 5/16 - 7/16 inch (8.0 - 11.0mm) turkey finisher: 7/16 - 5/8 inch (11.0 - 16mm) The last 2 sizes of grit can be used as ballast in the bottom of shallow pots by mixing 3 parts of grit to 1 part of your soil; this, to avoid water perching above the layer. The layer should be as tall/deep as the PWT your soil supports. Skip this if using a properly made gritty mix. Al...See Morekashu
14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agoshanielynn
14 years agolast modified: 9 years agokashu
14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agoshanielynn
14 years agolast modified: 9 years agoshanielynn
14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agoshanielynn
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14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
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14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agolesmatzek209
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14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agofiziklytired
14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agofiziklytired
14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
14 years agolast modified: 9 years agokatskan41
14 years agolast modified: 9 years agolesmatzek209
14 years agolast modified: 9 years agotapla (mid-Michigan, USDA z5b-6a)
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tapla (mid-Michigan, USDA z5b-6a)Original Author