Why I Prefer Leaves over Rock Dust to Remineralize Soil
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Why I Prefer Leaves over Rock Dust to Remineralize Soil


Autumn leaves are one of my favorite free, local, sustainable resources for the garden. I like them for a number of reasons, but today I’ll talk about why I prefer them over rock dust as a source of minerals for the garden. Trees mine minerals from deep in the soil and return them to the soil surface when leaves fall. Unfortunately, I could never find data on the mineral content of leaves. So, I was delighted when Stephen from Alberta Urban Garden sent a variety of local leaves – birch, poplar, apple, and Russian olive – to a lab for analysis. He also sent samples of two leading brands of horticultural rock dust to serve as a point of comparison in assessing leaves as a mineral source. I’m sure many of you have seen Stephen’s video on the results, but I’d like to provide my perspective as well. In addition to looking at the lab results, I’ll compare leaves to rock dust from the perspective of an environmentally conscious consumer who is looking for a quality product that is environmentally friendly, renewable, and reasonably priced. To help me evaluate leaves and rock dust as competing products, I’ve prepared a report card. I’m looking for a product that is organic, contains a full complement of essential and beneficial elements, and has minimal levels of harmful elements. Though I don’t expect the minerals to be immediately plant available, I’d rather wait months than years for them to become so. I’d prefer the product to be local and from a renewable resource. Minimal environmental impact and fossil fuel usage are very important to me as well. Finally, I’d like the product to be reasonably priced. I’ll grade on a scale from A, which is excellent, to F, which is failing. Admittedly, the grading will be subjective, but I’ll do my best to be fair. The first criterion is easy to grade. Both rock dust brands are certified organic and leaves are organic, so everybody gets an A. Now let’s compare the essential elements in the leaves to those in the first brand of rock dust, which we’ll call Rock Dust A. Stephen has already done a statistical analysis of the numbers, so I’ll be brief. Green shading indicates that leaves have a significantly higher level of an element. Red means Rock Dust A has a significantly higher level. No highlight means that the elements are in a similar range or the amounts are statistically insignificant in both samples. All numbers represent milligrams per kilogram. The nitrate and nitrite numbers represent only the available amount, but all other numbers are for total amounts – available and unavailable. At first glance, it’s clear that the autumn leaves fare very well compared to rock dust A. Leaves have significantly more nitrates and nitrites, phosphorus, sulfur, boron, and zinc. Though in a statistically similar range, the leaves also have more potassium, calcium, and nickel. Iron is the only mineral that is significantly higher in the rock dust. Though in similar ranges statistically, rock dust A has more magnesium and manganese. Copper and molybdenum are at statistically insignificant levels in both the rock dust and leaves. Based on the essential elements, I’d give leaves the higher grade. Now let’s look at beneficial elements. Both cobalt and selenium are at statistically insignificant levels. Sodium is significantly higher in the rock dust, but that doesn’t change my preference for the leaves. I have no reason to believe that our crops suffer from a sodium deficiency. Now let’s compare the essential elements in leaves versus those in Rock Dust B. Clearly rock dust B compares more favorably to leaves than did rock dust A. Rock dust B has significantly more magnesium, iron, manganese, zinc, copper, and nickel. Leaves have significantly more nitrate and nitrite, potassium, sulfur, and boron. Though in a statistically similar range, leaves also have more phosphorus and calcium. The molybdenum levels are not statistically relevant. This is a tough call. Leaves have higher levels of some very critical elements, but rock dust b has higher mineral levels over all, so I’ll give the advantage to rock dust B. Looking at the beneficial elements, we see that the rock dust has much more sodium, but this won’t impact my assessment. So, let’s put the grades in the report card for the essential and beneficial elements. I’ll give leaves an A-, Rock Dust A a B, and Rock Dust B an A. Now let’s move on to the trace minerals that have no known beneficial role in plant growth and health. In fact, many of them are quite toxic to plants and humans in sufficient concentrations. Looking at these minerals in rock dust A and leaves, we see that most are in similar ranges or at statistically insignificant levels. However, Rock dust A contains significantly more aluminum, barium, chromium, lead, and vanadium. Though these elements are toxic in sufficient concentrations, I’m not suggesting these levels pose a threat. That said, I see no reason to add more of these elements to the soil, and I definitely prefer the lower levels found in the leaves. The picture looks similar with Rock dust B, which has significantly higher levels of aluminum, antimony, arsenic, barium, chromium, lead, tin, and vanadium. Again, many of these are quite toxic. Though the levels here may not be high enough to be concerned about, they are also definitely not a strong selling point, so I much prefer the leaves. Returning to the report card, I’ll give leaves an A for “minimal levels of toxic elements”. Rock dust gets a C. While we’re here in the report card, we can quickly add a few more grades. Let’s start with plant availability. The minerals in both leaves and rock dust are not plant available. However, because the minerals in leaves have already been taken up by a plant, they will be available sooner than those found in rock dust. I’ll give the leaves an A and rock dust a B. Another advantage of leaves is that they’re local, while the 2 rock dust products have to be shipped from more than 1,000 miles away. Leaves get an A and rock dust gets an F. Leaves are also a renewable resource, while rock dust is not. Leaves get an A. Rock dust gets an F. Now let’s look at both environmental impact and fossil fuel usage. Returning leaves to the soil is definitely a plus to the environment, especially when the alternative is sending them to a landfill. And collecting them requires little to no fossil fuel, at least in our case. Most of the leaves are collected within a few city blocks from the house. When we do use the car to pick them up, we only do so when we’re already driving the car for another purpose and we happen to come across some bagged leaves. So, leaves get an A when it comes to environmental impact and fossil fuel usage. Mined rock dust is a very different story. Both of the rock dusts under consideration here are mined specifically for rock dust. In other words, they’re not simply waste products from another mining process. As a results, all of the environmental damage and fossil fuel usage incurred in the production and distribution of these products can be attributed directly to the products themselves. There are many environmental problems associated with mining, including air pollution, ground water contamination, excessive water and fossil fuel consumption, noise pollution, and destruction of landscapes and wildlife. Turning a mountain of rock into a fine powder comes at a cost. Most mining operations use the explosive ANFO – ammonium nitrate/fuel oil – to blast rocks. The ammonia in ANFO is produced using the Haber-Bosch process, which is the same energy intensive process used to produce ammonia for synthetic fertilizers. Drilling, crushing, and moving the rock requires large amounts of fossil fuels. And a great deal of water is required in the operation of crushers, to lubricate and cool drill bits and to suppress dust. Finally, shipping rock dust across country and around the world burns even more fossil fuels. So, while leaves get an A for environmental impact and fossil fuel usage, rock dust gets an F. Finally, let’s look at product cost. Free autumn leaves definitely get an A. The best price I’ve found for rock dust is 37 lbs for $44 including shipping. At that price, I could easily pay anywhere between $100 and $600 per year, depending on the application rate. That’s definitely more than I want to pay, especially when there’s a free alternative. I’ll give rock dust a C for cost. So, from the perspective of an environmentally conscious consumer who is looking for a quality product that is environmentally friendly, renewable, and reasonably priced, I believe leaves are the best choice. When I average the grades on the report card, leaves get an A and both rock dust brands get a C-. Fortunately, nature has already devised a way to recycle nutrients from deep in the soil back to the soil surface where shallow rooted plants need them. So, why rely on explosives, drills, crushers, and fossil fuels when you can rely on tap roots and leaves? Even if you don’t have deciduous trees in your area, keep in mind that all organic matter contains minerals that are released as organic matter decays. Compost made from a wide variety of inputs should provide more than enough minerals for most soils. As I mentioned earlier, the grades I assigned are admittedly subjective. If you would have graded anything differently, please let me know in a comment below. Before closing, I’d like to thank Stephen from Alberta Urban Garden for sharing his lab results. As we close, I’ll provide a link to Stephen’s video summary of the results. There’s also a link to the video in the description, along with a link to lab results Well, that’s all for now. Thank you very much for watching, and until next time remember you can change the world one yard at a time.

100 Comments

  • Susan Schrader

    Why choose if they are both available and each provide different (mostly) nutrients why not use both especially in raised beds?

  • BeeFriendlyApiary

    I add rock dust to our soil and also TONS of compost, leaves, and mulch. Our yard has gone from a solid mass of clay, with few to no worms, to an easy to dig black gold worm orgy…I would have everyone consider adding compost and leaves every single season to their gardens, but don't be afraid to add rock dust…rock dust WILL add more than just the minerals that were spoken about in this video.

  • Mr13Channel

    What happen if i take a bunch of leaf and blend them in my vitamix? Will that speed the progress of leaf decomposing? Will i lost any of the goodie by blending it?

    Make some leaf butter to feed my worm?

  • mongolioose

    There are other variables at work, for instance the original content of the minerals that the tree roots pulled them from. Not sure of rock dust creation, but I would think that even from the same company it would vary somewhat on a bag-to-bag basis. Just thinking…

  • Profound Organics

    Just curious; ….what do you have against Rock Dust ? In specific Azomite ? Is it the immediate availability of minerals you're looking for or just a completely natural way of securing useful organic material ?? I enjoy your videos and information…very helpful and useful.

  • A Kimbo

    Thanks OneYard. In Victoria, BC folks don't like to use leaves from our native garry oak because they say they are too acidic, but I collect as much as possible and shred them for my garden, which is predominantly native plants so they love these local leaves. My question is that I've had very poor root crops–lots of leaf but tiny bulbs, despite my great compost made of leaves, seaweed, kitchen and garden vegetation, egg shells, etc. Tried various things over the past 5 years but this year I added rock phosphate and wow my beets are a good size for the first time. I hear you about the impact on the environment, so I'm wondering how I can get phosphate into the soil from a natural source.

  • Johnny Fontenot

    Great Video! Watched a TED talk recently on composting leaves. The lecturer urged 'Leaf hoarding' lol. This afternoon I went to my local Little league baseball field where there was a huge pile of sycamore leaves wind driven along a fence. Within :15 I had 6 extra large bags filled, tied and loaded into my truck. Tomorrow I will send them thru my shredder and layer them in yet another compost pile outback. Rock dust….Nah, i'll pass as I am a 'frugal' gardener hence the leaf gathering 🙂

  • Esther Sewar

    Dear Patrick, You are really doing A Great Job with your extensive knowledge in gardening presented with your great personality.
    I am very encouraged to grow own vegetables and fruits by your rich harvest.
    All the Best,
    Esther

  • lxmzhg

    After all the hype I've read I was convinced that I should go out & purchase some rock powder. After watching this video, I'm glad I didn't yet make the purchase. I have plenty of leaves of my own & can get more free. The way to go!

  • Powell Gammill

    Even non-deciduous areas shed leaves throughout the year (instead of all at once) in similar amounts annually to the once at the end of fall. So not an issue.

    I am not certain the so called deep nutrient recycling really takes place to a great extent. It is dependent upon soil compaction and clay levels—if the roots cannot penetrate they don't. Also while all seeds have taproots that I am aware of, few last more than a few months to up to five years before apoptosis decomposes them. They are needed by the seedling to keep from being blown or washed away. But once a tree has established support roots (>90% located in the first 3 feet of soil) a taproot is merely a drain on maintenance. There are exceptions, but most species in most circumstances are limited to a shallow soil existence.

    Some plants are pretty good at bringing up minerals (bio-accumulators) from the deep if they can penetrate their roots down into the underlying soil. But they often bring up some undesirable elements as well.

    Bottom line however is leaves are the evolved way of recycling nutrients and we bag it up (along with pruning trimmings that could be chipped) and ship it to the dump while purchasing, transporting and spreading out manufactured fertilizers to take their place. That strikes me as intelligent . . . if you sell the fertilizer.

  • Jay Shriver

    I am so glad I just watched this!Last week I arranged for the City of Greeneville to drop off 8 to 10 thousand pounds of leaves, cost $75.I was here on U-tube studying up on what I should add to them in the way of Azomite, greensand, rock powders, etc.After having watched this I think, to make great leaf mold for next year's garden, all I have to add is spring water.Thanks

  • Trump01

    I've been gardening since the early 70's and really appreciate what Steven and Patrick are doing to advance simple techniques with regards to Compost, Worm Castings and Mulch. I've used many different Techniques over the years and the results have been all over the map. I've found that simple and local work the best. Many "gardening" products are contaminated and aren't listed as such. The product lines of Espoma and Jobe's are readily available to anyone who garden's and serve their purpose well. Most gardeners these days don't have time for all the research, which is why the youtube channels become so important. I always use Neptune's Fish and Kelp, Humic Acid, and Mychorrhizae, as a foliar spray and soil drench every other week, along with a small amount of Espoma/Jobe's 50/50 organic garden fert. mix and Mittleider's Micro Mix initially in the spring to get the garden off to a good start. I compost my deciduous leaves, grass clippings (Espoma Organic Lawn Fertilizer), Garden Plant wastes, over the summer and fall, and grow cover crops of clover when beds are bare. I change my soil every 3 years – my garden is only 30 x 60 – by spreading the used soil out over the grass, and elsewhere around the house where it's needed. I grow Krakty Lettuce with Crop King's Hydrogro for Lettuce with excellent results. I grow wheatgrass and sprouts and microgreens with Sea90 only, mixing dry with water @ 1/2 tsp per gallon for excellent results. I don't bother with rockdust in the garden beds as most rock powder products contain 15% or better of aluminum, and some or most contain high amounts of silica – both not desirable nor money wise. Leaves are best. I know where they come from and most in Michigan will contain adequate amounts of the majority of trace elements.The human body, blood, animals, plants, soils, oceans – all contain the full assortment of trace elements, with ocean water percentages matching closest to human blood. Maynard Murry and Joel Wallach both proved Ocean Minerals and Plant Minerals greatly benefit man. Because of the impending fall of our society as we know it, many will have no choice but to garden their own sustenance, just as our Grandfathers did in the 20s and 30s and 40s, and continued right up through the 60s. Most today have no knowledge of self reliance. They won't have access nor the money to obtain any of the latest gardening products throughout the country and will have no choice but to discover local solutions. Everywhere there is poverty around the world, the locals always turn to two things more than any other to grow food – Manure and Leaf Mould……..Earthworms take care of providing manure to us city dwellers, and imho earthworms provide a better product…..Everyone has their own methods, this is what has worked for me. I don't bother with soil tests any longer. I tell by the appearance of happy plants and terrific taste of my vegetables…..both are top notch…….thanks again for your exhaustive contributions to the gardening world…..

  • Don Cooper

    Hi Patrick, watching this video and the one on the ten things you don't / no longer do, made me think of a famous quote:
    "Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away" Antoine de Saint-Exupery. There are always new things we can try in the garden. As you've shown many times, it is important not to burden yourself with too many of these good things. Especially when you can achieve such great results with a small toolkit. Thanks to you and Stephen.

  • David Gual

    Loving your videos so far, but you should seriously consider taking some statistics lessons. For significant differences to exist between values A and B, there is no need for one to be three times bigger than the other. Also, and I'm pretty sure you already know this, one rock dust having higher values for several positive elements doesn't mean the leaves' values aren't already high enough for optimum plant growth.

  • democolor42

    I think it is very tricky to compare leaves and rock dust, leaves as carbon source are already ready to break down, while rock dust takes beneficial soil organisms like microbes, bacteria, fungi, mycorrhizae and etc. to be broken down and incorporated. In other word, this process takes longer time than leaves but by no means is less effective, Anyway, time frame still does not decrease the great significance of the rock dust minerals, which over time becomes golden addition in soil. I would say, both of them would make a harmony
    And what about gaia green glacial rock dust? I do not think they use same methods which you demonstrate, to blast them out and they come from very pure source
    Also nature really designed in its best way, but humans depleted those recourses, so are those leaves as rich as they were many decades ago?

  • Richard Pipes

    I was researching nitrogen fixing plants and the Russian Olive tree came up as one of the highest nitrogen fixers around. I saw evidence if this this spring.My folks have about 7 acres behind their house with mostly Russian olives. About 2 years ago they cut many of them down and where the stumps stick up there is very lush, green clumps of grass. My question is do Russian olive leaves also contain high amounts of nitrogen?

  • Richard Pipes

    Interesting point, the Russian Olive puts between 180 and 260 lbs of nitrogen per acre back into the ground every year! Wow

  • Richard Pipes

    I may try the green leaves as a composting agent. The trees are so invasive I'm not really concerned about harming them. Rather, this could be a great renewable free resource for this purpose.

  • Jose Dias

    Attention passionate defenders of rock dust… I somehow doubt this video was made with the intention of offending your sensibilities. Seems more directed at providing answers for someone more interested in lessening their impact on the environment while still adding some minerals to their garden.

  • yes350yes

    There are vids up on you tube which state that rock dust doesnt work or that its not obvious to the observer running the tests that its worth the expense. For my personal composting I go to my local town park in the fall and gather leaves , its only 3 mi from my house so not much expense in the way of gas. Its just my personal labor involved using my own bags. I wish I could find a better way to mulch the leaves though. I have been putting them in a large tote and using my weed trimmer to mulch them. Im not sure what the investment would be for a chipper shredder but Im guessing it would rather expensive just for mulching of leaves.

  • argentum taibhsear

    Depending on how much effort you put into collecting and processing leaves, you could factor that time and energy into the cost. If you have abundant free time to spend on it, it's not much of a cost but if you have to take time away from other things to spend it collecting leaves, the cost of dust could quickly become moot. I think the grading system needs more range too. The environmental cost of the dust seems more like a Z in comparison to the leaves being an A.

  • SunRa

    I am not a rock dust fan, Other than I feel it makes my soil a little easier to work (and is superior to sand) I think its a little unfair to give it a F on distance. Its available, usually for free at many gravel pits everywhere as filings near grinders and crushers. Its not ultra-fine dust often however.

  • Jonathan schadenfreude

    Remineralization Revitalizes Living Systems: Remineralization is a global initiative carried out through local land management practices which revitalize biologic ecosystems. Increased nutrient value in food imparts health up and down the food chain. The sustainable local sourcing of mineral rich rock dusts for agriculture and forestry contributes to good health locally. Globally, it supports geo-therapy initiatives aimed at capturing atmospheric carbon, stabilizing the climate by reducing atmospheric greenhouse gases. SOIL HAS THE GREATER POTENTIAL TO CAPTURE ATMOSPHERIC CARBON THAN ANY MAN MADE TECHNOLOGY. ROCK DUST LOCAL SUPPORTS BIOLOGIC FARMING and FORESTRY INITIATIVES

  • Jonathan schadenfreude

    F my ass, there's more than one way to grow top shelf veggies…..carbon sequest. edibles in vermont will take the pepsi challenge with ANYONE ANYWHERE!
    "… a one-pound stone might have a surface area of 12 square inches. Ground to about 200 mesh, it would have a surface area of about 8 acres. One ton would therefore have a surface area of 16,000 acres. The significant thing about that 16,000 acres is that it is all freshly-broken stone with the useful elements exposed right on the surface. These elements are readily available for extraction by the microorganisms."

    – John Hamaker
    The Survival of Civiliza

  • Gratitude Ranch

    I live in the Pacific Northwest. We have TONS and TONS of trees. In my yard we have many invasive maple species, which can grow quite tall, and send down a strong tap root very quickly. Last year I used our leaves to mulch the garden beds and come spring- I had HUNDREDS if not thousands (yes, that's correct) of them growing in my garden. Ugh….
    This year we acquired a used wood chipper that has a leaf shoot. I'm hoping chopping them to bits will make fewer of the seed helicopters viable next year.
    Thanks again for the fine video Patrick.
    Sorry for all my comments. As the season winds down, it's when I process, plan and research. Unfortunately for you, you're one of my favorite examples. Lol. Good luck!

  • whispers from my arse say

    my leaves are just picked up in my backyard… fuck i get to many its worse then snow ha. as soon as fall comes along its a never ending endeavor until winter while with snow last year i only had to clean the drive way 3-4 times

  • Firdous Valley

    I would choose to use both…John kolar has expressed great feedback regarding rock dust. I think it depends what rock dust your using, has it been activated into your soil…have you used enough of it…these tests sound a bit questionable to me personally.

  • Herb Halling

    You analysis is very interesting. I wonder how Volcanic Ash would compare to the rock dust. Volcanic ash is noncrystalline and basically salt free. Whereas rock dust is crystalline by nature. I think this would make a difference on how it amends the soil.

  • Kaylyn TW

    Because of your channel I've started to mulch with leaves. Our yard doesn't have enough so I've been going to the park with the kids and collecting leaves at the same time. I'm really interested to see how the plants do this year.

  • monomer2

    I'm not for nor against any product here but I do immediately see some issues with this contrived video comparison.  First, if all rock dusts are not all alike (and they are not thus the A and B approach taken in the video) then it is also true that not all leaves are alike, so why is there no leave pile A and pile B and pile C and etc. added to the report card?  Then there is the issue of shipping… if local soil is deficient in some mineral then it stands to reason the any plant matter grown in that soil would also likewise be deficient, so using local leaves wouldn't resolve the issue, however shipping in rock dust from hundreds or "thousands" of miles away (according to the video) could likely resolve such a mineral deficiency issue…. otherwise shipping in a bunch of leaves from hundreds of miles away (because of the huge volumes involved) would likely be a wash cost wise.  Thirdly, leaves would need to be replenished quite frequently compared to rock dust… leaves would likely need to be added on a yearly basis whereas rock dust is likely a one time addition because it releases on a geologic time frame.  On the other side of the coin, leaves eventually become humus and thus bring with it all the good things that that entails, whereas rock dust is… well, its rock.  Also leaves feed the microbial (and macro) populations in the soil food web.  What I'm trying to say here is this video comparison is kinda bogus… there really isn't a leaves vs rock dust choice… each has its own merits and bring benefits to the garden.  This is a false choice as one can have both in the same garden and enjoy all the benefits.

  • Blast of Fresh Air

    I can agree with environmental reasons (in favor of leaves) regarding some rock dust; however, leaves will only have those minerals in them if they are from a plant which is grown in rich soil right? and if they have the microorganisms to help break them down too

  • CaseyCJL

    I think you have the most informative gardening channel on youtube! Thanks for all your effort, you have really helped me to improve my garden.

  • AlexMW

    I wouldn't trust the criminals at large to give me some product that would make me healthier… not even in rock dust much less food. They will always add their little surprise elements that will be a detriment to your health which is what this video showed

  • Vlad The Impaler Țepeș III

    I agree. I also think that using rock dust, IMHO, isn't organic because you have to pulverize rock and the nutrients released too quickly and unnaturally. I leave rocks in my soil because I believe they release nutrients SLOWLY over time. I look at rock dust like refined sugar – No bueno in the long run.

  • Rick's backyard garden

    I'm glad this video popped up after I watched another one of yours today. I've only used leaves plus some lime on my garden for many years and have been happy with the results. It's a good way to get rid of my leaves also and I don't have to buy mulch either. Thanks Patrick, for another great video.

  • Bzz

    I'm so glad I stumbled on this video before buying a bag of expensive rock dust. Thank you again! I've learned so much helpful info from you.

  • Ruby Gray

    If you lived in Australia with our preponderance of evergreens (we have only a single deciduous tree, and it does not grow near people), you might have to find a different source of minerals too! There's no doubt autumn leaves are gorgeous on & off the trees. I traveled through several US states on the train, and saw hundreds of miles of astonishingly beautiful autumn-leafed trees. We just are not so fortunate here.

  • John Wakamatsu

    I totally agree with you that using leaves is much more effective in many ways and should be used instead of rock dust. I grow many different type of trees and plants without the use of rock dust and use organic fertilizers instead of chemical fertilizers. I believe that building up the soil with soil organisms and nutrients is much better than increasing salt content using chemical fertilizers. I also know that adding too much nutrients to the soil promotes agricultural runoff pollution which can harm the environment. I worked as an chemist for almost thirty-nine years and many years as an environmental chemist for a very large utility.

  • Thumper700

    I till 6-8 inches of shredded leaves into my garden every fall- been doing this for 3 years. Without a doubt, my soil is improving every year, and my plants' production is increasing too. The earthworms are ridiculously thick in my garden; I'll never have to buy nightcrawlers for fishing again!

  • Patricia Nunez

    Thank you so much for this information! I am definitely not going to use rock dust. I mow my leaves with the grass and pile it on my organic no-dig cottage garden beds. Plus composted manure, homemade compost and organic fertilizer.

  • Veronica Williams

    WI guess its to late for me to get the leaves but this fall I will rack them up rite in the hood Lol thank you pat thats my son name name after his father I learn some new daily thanks again.

  • James House music

    Hey Patrick it would be very interesting to see a batch of backyard compost made from leaves cardboard kitchen scraps garden waste and possibly rotted manure ,compared scientifically to the rock dust ,

  • Sweet Pea

    Great info Patrick! I have a medical reason to stay away from chemicals in my diet but I want to use leaves and wood chips derived from the community around me. Can you comment or do a study about chemical contamination of leaves and bark from sprays and lawn fertilizer/weed killers? Thanks!

  • Pamela Clare

    I have a question about leaves. How do you know whether the leaves from neighbors have pesticides? Some people control tree pests (honeylocust bug, aphids) by having pesticides injected into the roots. Those pesticides end up in the leaves, which is how they kill the bugs. I imagine they stay in the leaves, but who knows? So do you ask first before you take someone's leaves?

  • Sky Dog

    Our city(Calgary AB) soil is mainly highly compacted black rock dust with chunks of gray, white, brown, red and jet black clay chunks. My yard is completely lumpy w/ all of the thousands of earthworms making their squigly little pyramids everywhere. Does this not count as worm castings?

  • Argost Abernackie

    I really want to thank you for this video. As a first time gardner I kept dancing on the fence about saving money on rock dust I really didnt think I needed to buy. And the report card in this video really made the choice easier for me, thank you for explaining in detail.

  • Oak Knob Farm

    Nice comparison, thank you. I just started getting "serious" about collecting and managing leaves last fall. I chopped all of my leaves with the mower, collected them with the truck, and moved it all to a big pile in an out-of-the-way place. I stirred it once so far this spring, and intend to do so once a month or so. I was able to get about 10 cubic yards of leaves (which will likely compost down to 3 or 4), and I'm very excited to see how well it works

  • Lore Brown

    Thanks Patrick, I was wanting to get chromium and vanadium into my soil because they play a role in keeping diabetes at bay. More diabetes on the rise now, due to depleted soils. I do use leaves so that should cover it. I'm with you on being thrifty and small compost footprint. Thanks, I learn a ton from you!

  • Inkdraft

    Thanks for the info. Excellent presentation. You get an A+ for saving my money for me.Additional benefits of leaves: Invigorating exercise raking (blowing, not so much) then bending and straightening as you stuff them into bags to lug to the garden. A feast for the eyes as the brilliant colors swirl around, and a healthy dose of vitamin D from working in the sunshine. I subbed too.

  • Xavier Dequaire

    actually rock dust can be obtained as a by-product of mining, tunnel or well excavation etc.. that you can get for free from a local quarry or building site

  • 123

    I mean all this says to me is to use both together in conjunction for the best results. It's not a competition, and the "toxic" elements are too low to ever be a concern. This test also fails to take into account the bioavailability of the nutrients and the actual nutrient density of plants grown in each soil, water retention/surface area benefits of rock dust, the abrasive nature of rock dust in worm digestion, etc. Inconclusive and too tunnel visioned on soil nutrient density imo.

  • Francis Lim

    The tree known as THE MIRACLE TREE,Is proven to hold the highest minerals,amino,enzymes and essential,we can uses the leaves as a rejuvenator for our soils,great benefits with these trees is they grows in depleted lands from semi tropical to tropical and can thrives in deserts when heavily mulched with wood chips,it’s called the MORINGA. a natives from Northern India.

  • Ruby Trotter

    I've never used rock dust. I've always used what I had: leaves, grass clippings, wood chips, rotten straw or hay, broken down wood from inside fallen tree trunks. This works well for me.

  • Masca Trails

    In my local area, gravel is mined regularly and screened for different qualities of rock size. It is possible to go down to a local quarry and buy some rock dust that is separated out from the larger grades of gravel. This can significantly impact the grades of local and fossil fuel usage and have a minor impact on cost and environmental impact. If someone doesn't have access to autumn leaves, buying rock dust at your local quarry can be quite a bit better than buying a commercial product shipped across the globe.

  • Gerry Clough

    Yes, I'd use different grades, especially as some of the easily available rockdust products here in Australia ARE a by product of producing roadbase or other products.
    However, using locally available and free product is surely better for the world as long as all the minerals are there.
    I gather leaves from local parks and floodways as here in Australia going out and gathering from National Parks is a big nono and neighbors still tend to use chemicals.
    I make sure to gather a good mix of different leaves.
    I still use rockdust as well but in smaller quantities.
    Most years I can store enough autumn leaves to last me to the end of the next summer before I run out 🙂

  • Daniel Foster

    Thanks for this very informative and detailed video. This will definitely change the way I think of fallen leaves. I have always used them for mulch and composting, but I mainly considered them a source of organic matter rather than minerals. It would be interesting to see a comparison with the mineral content of wood ash. This can also be free (for me anyway) and I have always had good results from using it here in England (in compost heaps, for growing vegetables, as lawn treatment etc.).

  • Nicolas Bertin

    I don't think people who garden on a living soil need to bother with those charts and mineral contents anymore. Fungi through mycorrhizae bring all of these to the plants by taking them in the soil around them or by breaking up the bedrock with enzymes.

  • king james488

    kinda silly your report card criteria favor leaves… what about things like store-ability, time to wait before you can use it, ease of use, etc.?

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