Does Pumice Interest You?
I have been reading, as many of us newbies do, about different growing mix components. Is there anyone out there who can show me (pic) the product you use as pumice? I want to see particle size, texture etc. I have been using Growstone, an expanded silica product, which I have thought is a fair substitute for pumice, since I can't get the real deal in Michigan without major shipping costs.
Also, can someone show/tell me what "decomposed granite is? And how is it different from the granite I purchase at a feed store; chicken grit/turkey grit?
This is Growstone. It is somewhat porous and very light-weight.
Comments (135)
cactusmcharris, interior BC Z4/5
8 years agolast modified: 8 years ago
Nicholas C.
8 years agoRelated Discussions
Let's talk soil amendments, e.g. pumice, pine fines
Comments (12)Hi Lynn: Thank you for sharing your experience with gypsum. EarthCo. also recommended gypsum for my soil ... never mind that I'm next to a limestone quarry, plus a gypsum plant. Bluegirl wrote in another thread on how she broke up her clay with gypsum. I have similar success using gypsum to break up my rock hard-clay. I get gypsum for $7 for 40 lbs. bag at my local feed store. It's quite acidic (has a higher % of sulfur), and burns my hand. So I always wear gloves when handle gypsum. The Encap sulfur sold at Menards $6 for a tiny 1 lb. bag contains a good % of gypsum .. I no longer buy that sulfur bag, since gypsum is cheaper, plus U. of CA at Davis documented that 1 lb. of gypsum is equivalent to using 5 lbs. of sulfur. I agree with their research. I put tons of that Encap sulfur on my clay ... did nothing, until months later, and tons of rain (at pH 5.6) ... then the soil finally crumble. With gypsum, it takes a few days to make my clay fluffy. Many sites and U. of Extensions alert that superphosphate harms the mycorrhizal fungi that help roots to obtain phosphorus & other nutrients from soil. However, Roses Unlimited recommended putting triple super-phosphate NPK 0-52-0 in the planting hole. So I put that stuff inside the planting hole of Queen of Sweden, plus sulfur. The flowering is 1/2 the rate of other roses without superphosphate. That's for 2 consecutive years. Last month I dug up Queen of Sweden, the root is woody & fibrous and reached down below. But there's an absence of secondary roots, or cluster-network. I didn't put superphosphate in Honey Bouquet, and when I dug that up, there's the fibrous brown woody main trunk, plus a vast network of secondary roots. Honey Bouquet gives 3 times more bloom than Queen of Sweden, at 1/5 the size. One of the danger of superphoshate is it also contains the toxic chemical cadmium, that would be poisonous is absorbed in edible plants. Plants can only utilize a small percentage of given phosphorus, the rest is quickly bound up with other elements in alkaline condition. When I use superphosphate in soluble form, as in MG Bloom Booster, it's really hard to dissolve. So I put vinegar in the bucket ... yet I still get phosphorus crystal stuck at the bottom. See below link of Australian Agricultural field study that showed APP (ammonium polyphosphate in fluid form) surpasses granular phosphorus. There's another Australian study that showed that the use of granular phosphorus over a span of 5 years did not increase their wheat yield much. I tested SOLUBLE Bloom Booster NPK 10-52-10, similar to APP, and the result was very good, if I use at 1/4 dosage. Too much chemical phosphorus can burn roots. Just a little bit helps roses with wimpy roots that can't acid-phosphatase, such as Jude the Obscure. Most roses don't need Bloom-Booster, they can secret acids to unlock phosphorus-tie-up in alkaline clay. It's the wimpy own-root like Jude the Obscure that has to be spoon-fed due to my alkaline water at pH 8. I use soluble fertilizer for pots, since pots leach out nutrients with our rain. In my alkaline dolomitic clay, no need for chemical fertilizer. My clay is fertile, with plenty of bacteria to fix nitrogen (air is composed of 78% nitrogen). I don't fertilizer my 26 trees, yet they are taller than 2-story house, plus lose leaves every winter. See picture below of my center garden, zone 5a Chicagoland: Here is a link that might be useful: APP fluid fertililzer surpasses granular phosphhorus This post was edited by Strawberryhill on Sun, Dec 8, 13 at 14:53...See Morere-visiting napa floor dry, dry stall etc.
Comments (20)In a spirit of cutting expenses to increase profit, makers of oil dry and kitty litter products could easily, it seems to me, switch to product that breaks down easier but still gets the primary job done more inexpensively. I'm not sure it would ever occur to them to consider the needs of gritty mix gardeners. The same goes for my chicken grit- I worry they might start to cut out some of the granite in favor of another component that is harmful to plants, if it suits the bottom line w/o harming chickens. They very likely don't know bonsai from banzai, crested cactus from crest tooth paste. I am swayed more these days to switch from 'cheap and local' to components specialized to my growing. I don't want a plant I have been caring for for ten years to die in a mud bath or from a toxic component. Good thread. ez...See MoreA potting get medium experiment, and some questions.
Comments (21)Amy Thank you...I think the original post can be edited only for about 1hr (?) after posting - I did some of my posts in the past, but within less than 1hr. After that, edit button disappeared. Posts within the thread can be edited for at least days if not longer. Not sure to whom your question about removing nursery soil is directed? I unpot the plant, shake off soil. Tease it out gently with chopstick or similar. If too muddy or too hard, I swish the root ball gently in bowl of water. Outdoors, I spray it with a water from hose. If peat has dried to a hard ball around roots, it is difficult to re-wet. I use tepid water, and sometimes leave plants roots soaking until it is soft enough. ps: I added some prices I pay for different ingredients to my previous post....See MoreComparing Pumice, Sand, and Turface in Structured Soils
Comments (19)Looks like one of your earlier posts just showed up in my feed now. I am afraid I am going to basically repeat myself but here it goes. You asked: "I thought that most of the perched water table was about the water that is *outside* of the particles in the soil? I thought it was the forces of adhesion, cohesion, and capillary action that mostly determined where the perched water table would settle. The whole point of using some soil components with high water retention is to store water inside particles in a way that benefits the plants over the next few hours or days without robbing the soil of oxygen in between particles." PWT is solely determined by the GAP between particles. Smaller the gap higher is the PWT. The gap is related to particle size and size ranges. If the particles are large enough the gaps are also large and vice-versa. If most particles are largish and a fraction of the particles are smallish then the small ones will fill the gaps between larger ones and make the gaps smaller on the average. It takes relatively little of the small ones to kill the gaps created by larger ones. So you see if you add peat to any medium it will not matter because it will kill all the air gaps. That is also why I keep insisting on knowing what other components are used in the mix. Surface tension as the name implies refers to the water at the surface of the particles. Surface tension tries to pull up the water through the gaps while gravity tries to pull it down. Smaller the gap higher is the force pulling the water up. That is because the amount of available surface becomes relatively larger than the air gap between particles. Sort of like a wick. And so the PWT is higher. Within PWT region every (most) gaps are saturated with water. There is no air in PWT region. Above PWT the gaps will be composed of air and water. Higher you go the proportion of air increases. That is what your graphs are telling you. The value at 0kPa is the total capacity also called total porosity. For peat it is 90% and for sand it is 30%. Means that is the maximum space available for water and air to occupy. At 0 kPa every space is occupied by water. At 1kPa it is about 80% for peat and 20% for sand. 1kPa = 4inches of water. Means if you go up 4inches in the container then peat will have 80/90 = 88% of available space filled with water. For sand it will be 20/30 = 66% of available space filled with water. The rest of the available space is air. But you have to know particle sizes too to make sense since those curves will be will be wildly different. The amount of available space will vary with particle size ranges. For a well made gritty mix the curve will be very steep and quickly fall to to a steady number (like pumice) within a fraction of kPa. Total water retention is sum of water within and outside the particles. So is the total air in the mix. A good structured mix primarily relies on water held inside particles to provide water and the gaps between particles to provide air. A much smaller amount will be held at the surface of the particles also available for plants. See the pumice curve where it flattens out. That is the amount of water held within pumice. For sand it is negligible amount held at the surface. Peat has some great properties but has no place in a structured soil. If you want to use peat then keep it below 20%. Use some combination of sifted pumice, turface, grit etc for the rest....See Morerooftopbklyn (zone 7a)
8 years ago
Crenda 10A SW FL
8 years agocactusmcharris, interior BC Z4/5
8 years agolast modified: 8 years agoCrenda 10A SW FL
8 years agoNicholas C.
8 years agobikerdoc5968 Z6 SE MI
8 years agoCrenda 10A SW FL
8 years agoI guess there is a Turface All Sport after all. I found another new Site One store in Fort Myers. They asked how I was going to use it and said to get All Sport (in lieu of MVP that they don't carry) because it has bigger particles that All Sport Pro. He said this is what his wife uses on her succulents. (Of course I have no idea if his wife's plants are thriving, but she is smart enough to be making a gritty mix.)
It was $23 for a 50 lb. bag. Much higher than NAPA, but will be worth it if it works well. I have no idea yet about how much of this bag is fines. This is a handful out of the bag.
bikerdoc5968 Z6 SE MI
8 years agolast modified: 8 years agoMy boxes of pumice arrived today from General Pumice Products. I am happy to say the product is as described. I ordered the larger ⅜" pumice; I was undecided as to which to order first...3/16" or ⅜". Now that I can see the product up close and personal, I will order the smaller size, also.
The product arrived in two medium flat rate boxes.
Prior to opening the containers, I weighed each and found they were a few ounces light.
Upon opening the boxes, I found the product in heavy plastic bags.
I found almost no fines and the pumice is dry as advertised.
Here is the actual weight of the product without the USPS Priority box.
Other than being a few ounces light, I would order from them again. I am going to place another order for the ⅜" size today.
bernardyjh
8 years ago
cardiovascular
8 years agocactusmcharris, interior BC Z4/5
8 years agolast modified: 8 years agobikerdoc5968 Z6 SE MI
8 years agolast modified: 8 years agorooftopbklyn (zone 7a)
8 years agobikerdoc5968 Z6 SE MI
8 years agoCrenda 10A SW FL
8 years agoReptibark is the name of fir bark for pet reptiles. Many pet stores sell it and some of us use it in our gritty mix. Chunks are a a little bigger than ideal, but I have used it right out of the bag.
Crenda 10A SW FL
8 years agobikerdoc5968 Z6 SE MI
8 years agobreton2
8 years agorooftopbklyn (zone 7a)
8 years agolast modified: 8 years agobikerdoc5968 Z6 SE MI
8 years ago
nomen_nudum
8 years agolast modified: 8 years ago2.25 inch TC pot view 100 % turface pot 9 months later
treated under the same day to day cultivating conditions as a pot holding a lithops with out a lithops
Company review question for Bikerdoc. On a 1 - 10 scale........ satisfied ?
nomen, we were able to get a large garbage bag of it for around $10 (US) - of course that was 10 years ago....
10 yrs later & you finally tell us LOL , and I though I was a hoarder.
if anyone is looking for bark fines on a budget ?A 3.5 cubic yard bag from Agway yielding a low % of sapwood thin enough for easy hand breaking even easier after warm water soaking Cost per bag from Agway Each Agway varies some will have it some wont others will offer close to the same some may even offer bark mulch fines to be better than what you see. Can't remember exact cost but was less than 10.00 per bag.
rooftopbklyn (zone 7a)
8 years agobikerdoc5968 Z6 SE MI
8 years agonomen_nudum
8 years agolast modified: 8 years agobikerdoc5968 Z6 SE MI
8 years agoAn update. I just received my order of 3/16" pumice from General Pumice Products. I am 110% satisfied with their product. Every bag (3) weighed slightly more than 15 lbs, the product is DRY and there are almost NO FINES! As a comparison: The product on the left is Nature's Footprint Pumice, 5 gal selling on Amazon for $23.75. It is evident the product is still damp after being open to the air for over a month and the significant amount of fines compared to usable pumice for succulents. If you go online and search Amazon for "pumice", you will see a picture of pristine pumice: not what is delivered. This is why they refunded my purchase price. The product on the right is from GPP. I think you would have guessed that on your own! For some of you, there may be less costly or better resources for pumice, but for me there is ONLY ONE place I will purchase pumice in the future! Thank you Lexi and Austin.
nomen_nudum
8 years ago
PROGeneral Pumice Products
8 years agonomen_nudum
8 years agoA duel thread being crossed linked to each other
http://forums.gardenweb.com/discussions/3563803/pumice-vs-lava-rock?n=4
I commonly reference the three common colors that I have on hand as pumice
The three colors and what they actually are.
White: Pumice
Black: Lava rock
Lighter shade of red: Scoria
Dry stall, also white to my understanding is a highly compacted volcanic ash that tends to be more micro porous than any common color of pumice.Dry stall unsifted
Dry stall sifted and rinsed with actual yield after soaking rinse and sifting
rooftopbklyn (zone 7a)
8 years agocactusmcharris, interior BC Z4/5
8 years agorooftopbklyn (zone 7a)
8 years agolast modified: 8 years agolmontestella
8 years agolast modified: 8 years agobikerdoc5968 Z6 SE MI
8 years agocactusmcharris, interior BC Z4/5
8 years agolast modified: 8 years agorooftopbklyn (zone 7a)
8 years agolast modified: 8 years agonomen_nudum
8 years agolast modified: 8 years ago
hellkitchenguy Manuel
8 years agohellkitchenguy Manuel
8 years agohorti2791
8 years agolast modified: 8 years agohellkitchenguy Manuel
8 years agohorti2791
8 years agolast modified: 8 years agohellkitchenguy Manuel
8 years agolast modified: 8 years agobikerdoc5968 Z6 SE MI
8 years agonomen_nudum
8 years agobikerdoc5968 Z6 SE MI
8 years agolast modified: 8 years agoI find pots 'seem' to dry more quickly using pumice. Pumice 'seems' to weigh slightly more than Growstone®.
There is no question that some dust comes with the GPP product. It will wash out when I water plants so I don't bother to pre-wash. And, yes, we are all creatures of habit and this is good; heads not shaking. I will say the GPP product is significantly better that what I purchased from the Amazon distributer. The product was wet, therefor the weight was inaccurate. After screening you can see the portion of fines (right) from two bags that were supposed to weigh 20 pounds each and there are still some smaller particles in the screened portion. The GPP product I received (5 bags) required no screening.
- PRO
General Pumice Products
3 years ago
General Pumice Products