Container Soils - Water Movement and Retention 8/26/21
tapla (mid-Michigan, USDA z5b-6a)
2 years ago
last modified: 2 years ago
Featured Answer
Sort by:Oldest
Comments (100)
Seth
last yeartapla (mid-Michigan, USDA z5b-6a)
last yearRelated Discussions
Container Soils - Water Movement & Retention X
Comments (153)Not at all, and I don't remember writing anything that should leave anyone with that impression. If I had to identify the crux of the thread, it would be that to take advantage of highly aerated media and their sharp drainage, it's essential to start with a very large volume of coarse ingredients, and there should never be enough fine material to fill all the spaces between the large particles. When you add a marble/perlite) to a jar filled to the rim with sand or peat), aeration of the medium in the jar DECREASES, and continues to decrease as you add more marbles/perlite. It is only when you have added a volume of marbles/perlite) so large there is not enough sand/peat) to fill all the desirable pores between the large particles that aeration begins to INCREASE. This is called the "threshold proportion". Al...See MoreContainer Soils - Water Movement and Retention XI
Comments (150)Hi Al, With all the ingredients in hand, I've started the sifting process and had a few questions. I'm trying to swap out 50 containers worth of soil so I'd prefer to do this in the most efficient way. I am using a 9x9 hardware cloth (.088" openings) to filter the fines. Here are the three ingredients I was able to source: 1) Shasta: Orchid Fir Bark: (1/8" - 1/4") http://shastabark.com/products.htm 2) Turface MVP 3) 1/8" Crushed Granite (Desert Gold) http://www.lyngsogarden.com/index.cfm?event=Display.Home.Product.Group&homeCategory=STONE&categoryid=1094&productgroup=PEBCOB&groupname=Pebbles%252C%2520Cobbles%2520%2526%2520%2520Colored%2520Gravel Questions: 1) It seems like it takes a decent amount of time to screen out the fines for one container. I also have constructed two other screens to be used to filter out the larger particles (a 1/4" for the large fir bark and a 9x9 (.1387") for the larger turface/granite). I'm assuming that at the end of the day it is more important to screen out the fines then to screen out the few larger pieces which may be in the mix. Would this be correct? I'm just trying to save some time and there doesn't seem to be that many larger pieces in the mixes. 2) Do you usually rinse out the mixes before you combine them? Does this help get additional dust/fines out? 3) What do you do with all the fines/dust that you sift out? If you are screening out larger pieces what do you with them? Thanks so much in advance. Your advice and guidance have been invaluable. Best, Kernul1...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 MoreContainer Soils - Water Movement & Retention XII
Comments (150)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....See Morechamaegardener (Z5) Northeast Illinois
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a) thanked chamaegardener (Z5) Northeast Illinoistapla (mid-Michigan, USDA z5b-6a)
last year- tapla (mid-Michigan, USDA z5b-6a) thanked chamaegardener (Z5) Northeast Illinois
tapla (mid-Michigan, USDA z5b-6a)
last yearwestes Zone 9b California SF Bay
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a) thanked westes Zone 9b California SF Baytapla (mid-Michigan, USDA z5b-6a)
last yearchamaegardener (Z5) Northeast Illinois
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a)
last yeartapla (mid-Michigan, USDA z5b-6a)
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a)
last yearchamaegardener (Z5) Northeast Illinois
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a) thanked chamaegardener (Z5) Northeast Illinoiswestes Zone 9b California SF Bay
last yearJacques Frost
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a)
last yearlast modified: last yearSeth
last yearfour (9B near 9A)
last yearJodiK
last yearNils
last yearlast modified: last yeartropicofcancer (6b SW-PA)
last yearlast modified: last yearNils
last yearlast modified: last yearbeccaboo_
last yeartropicofcancer (6b SW-PA)
last yearlast modified: last yeartapla (mid-Michigan, USDA z5b-6a) thanked tropicofcancer (6b SW-PA)tropicofcancer (6b SW-PA)
last yeartapla (mid-Michigan, USDA z5b-6a) thanked tropicofcancer (6b SW-PA)Fahmy
11 months agofour (9B near 9A)
11 months agoFahmy
11 months agolast modified: 11 months agoJodiK
11 months agoBillMN-z-2-3-4
11 months agolast modified: 11 months agotapla (mid-Michigan, USDA z5b-6a) thanked BillMN-z-2-3-4Ben (Colorado, USDA Z5)
9 months agotapla (mid-Michigan, USDA z5b-6a)
9 months agoBen (Colorado, USDA Z5)
9 months agoErrata Sama
9 months agoa1an
9 months agotapla (mid-Michigan, USDA z5b-6a)
9 months agolast modified: 9 months agotapla (mid-Michigan, USDA z5b-6a)
9 months agowestes Zone 9b California SF Bay
9 months agolast modified: 9 months agoSeth
9 months agowestes Zone 9b California SF Bay
9 months ago
Related Stories
CONTAINER GARDENSBeat the Frost With Natural Terra-Cotta Containers
Here's how to protect your pots during the cold winter months
Full StoryLANDSCAPE DESIGN8 Trees Landscape Designers Love for Small Spaces
Learn more about the top-performing trees to grow in tight corners, city courtyards, narrow side yards and more
Full StoryFEEL-GOOD HOME21 Ways to Waste Less at Home
Whether it's herbs rotting in the fridge or clothes that never get worn, most of us waste too much. Here are ways to make a change
Full StoryLIFEThe Top 5 Ways to Save Water at Home
Get on the fast track to preserving a valuable resource and saving money too with these smart, effective strategies
Full StoryREMODELING GUIDESLiving Roofs Crown Green Design
Living roofs save energy, improve air, water, curb appeal — and the view from above doesn't hurt either
Full StoryGARDENING GUIDESGarden Myths to Debunk as You Dig This Fall and Rest Over Winter
Termites hate wood mulch, don’t amend soil for trees, avoid gravel in planters — and more nuggets of garden wisdom
Full StoryGARDENING GUIDESNew Ways to Think About All That Mulch in the Garden
Before you go making a mountain out of a mulch hill, learn the facts about what your plants and soil really want
Full StoryGARDENING GUIDESHow to Get Your Prairie On
Have a field day with your landscape, even if you've got just a few modern containers on a paved path
Full StoryMOST POPULARThe Perfect Houseplant for People Who Kill Houseplants
If you can fill a jar with water, you can keep golden pothos vine happy — and it will pay you back with cleaner air and a greener home
Full StoryGREEN BUILDINGHow to Harvest Rainwater for Your Garden
Conserve a vital resource and save money by collecting stormwater for irrigation in a barrel or tank
Full Story
tapla (mid-Michigan, USDA z5b-6a)Original Author