Checking in at long last. I've been on a road trip for the last month. Coming back to a clean slate (pulled up the summer plants, which fried, before I left) and am now trying to get my soil up to snuff for the fall garden. I could use a refresher. I can't think what I need to do.
What I *KNOW* I want to do is dump my one trash bin of finished compost evenly across all my beds.
After that...what? I have a bunch of stuff at my disposal and hope to not have to buy too much more. Here's what I have collected over time:
a few bags of shredded leaves
3 cu. feet of pine bark fines
small bag of miccorrhyzi (however that is spelled)
small bag of azomite-type mineral stuff (different brand)
granulated fertilizer (espoma, I think)
small bag poultry manure
What do you think needs to go into what are probably "tired" raised beds?
For starters I would apply the poultry manure and mix that in with the current soil. Then cover the soil with a layer of that bag of finished compost. Then I would seed or plant whatever you you want to grow this fall. Then spread some of the granulated fertilizer. Then water it all in. I would not do anything more for your fall crop.
I would compost the shredded leaves and pine bark fines for future use. Shreaded leaves can be quite acidic depending on what tree they came from. I'm not really into using the seaweed, mycorrhizae, azomite, molasses, blood meal(nitrogen), bone meal(phosphorus) etc.
Epsom salts (magnesium sulfate) I would only apply if you know that you have low sulfur o low magnesium. Some gardeners swear by it but I have never seen much results from Epsom salts even when those two nutrients are low. Some say it most affects tomatoes and peppers as well as roses but I'm guessing you arent planting any of those for a fall crop.
You could add the blood meal and molassesn to the shredded leaves and bark fines as an accelerant to speed up composting. The nitrogen in the blood meal will help the microbes more efficiently decompose the organic matter.
I think pine bark fines are good to mix with soil even without composting them. As you point out, bark fibers are great for drainage.
And they break down more slowly that wood of the same particle size. And they have more nitrogen than wood. Thus they cause less nitrogen deficit than wood would.
I would have saved the manure and mycorrhiza for the rows or holes where you plant things. If you have only a small quantity, it might be worth some extra effort to concentrate them where the roots will be. If you do "intensive" plant spacing, its not an issue.
Bark fines should be widely distributed and well mixed, since you need good drainage everywhere, not just in spots.
I would save the seaweed and meal for planting holes or rows. Maybe save the granular fertilizer for side-dressing halfway through the season, depending on when the crop wants extra minerals.
My practice is to always compost things like leaves before mixing into soil. But the idea of using them as sheet mulch, sheet compost, or spot compost certainly gets 100% of the nutrients into the soil ASAP. I guess the question is whether your soil can stand to have any Nitrogen sucked up by composting microbes. "Tired soil" sounds like maybe it can't!
I have to disagree with spreading the granular fertilizer (or bone meal) on the top of the soil. Nitrogen will move down, the phosphorus and potassium doesn't redistribute itself so well. When possible, they should be mixed into the root zone to make them more available.
It's important to remember with all this talk of mixing that if you have good tilth, tearing it up and mixing things in will destroy it. If you are the kind of gardener who tills every spring, this is moot but since these are raised beds you may want to rethink. If there are specific ingredients you want to add, an alternative would be putting them in the transplant holes when you dig them.
Me, I'd use the organic matter and nothing else unless you have a proven need for it. You say they are "probably tired." To me, it makes more sense to find out instead of throwing the kitchen sink at it and hoping it works. Too much of certain minerals is as bad as too little.
I too, am working toward refreshing my beds, and have a bunch of stuff in the garage that I'd like to clear out. I'd also like your advice on what to put, where, for the fall brassicas.
Here's some what I have:
2 cf. bag of garden soil
Large bag of coarse Perlite
Large bag of Vermiculite
8-10 contractor-size bags of shredded, year-old oak leaves
Pine Bark Fines (the larger-than-half-dollar chunks I sifted out of my mixes - I could shred them through a wood chipper...)
Liquid seaweed, Kelp Meal, & Molasses
40 lb. bag of Chickety Doo Doo (poultry manure, original bought for the lawn...)
40 lb. bag of Soil Conditioner (again, for the lawn)
Here's where I can incorporate stuff:
RB #1 currently has eggplants and Swiss chard that are still cranking out. This is a very good bed! It doesn't need much added to it, except for a little topping off once I pull the eggplants. Last fall this bed had beets & turnips. Next up: Beets & turnips!
RB #2 had bell peppers this spring one-third of the 4x8' bed, but they never produced fruits (very few, and very small). The remaining 2/3 of the bed was empty. I'm wondering if it was the plants or the soil in this bed...Cabbages and Kale will go in this bed next...
RB #3, the spring tomato bed, is finished, and the dried up vines will be pulled this weekend. Broccoli and cauliflowers going in next, in 6-8 weeks. The bed has shrunk back a bit, and could stand topping off...I grew the broccs and caulis here last fall/wtr. and they did very well in this spot. I know from past experience that these Hungry Hippos like a lot of organic food in the soil, as they eat regularly. Should I mix in some of the shredded leaves and the garden soil into this bed? Also, the PBFs help the drainage.
Thanks for the further comments. Yeah, I bought the various smaller amendments with the idea of putting them down at specific planting sites, and/or to make foliar sprays and whatnot -- I only put them all onto the above list because that is, in fact, what I have on hand. But it doesn't surprise me to hear "save it for when you plant." It makes sense to me. And I'm glad, that stuff costs money!
I did throw my mostly finished compost onto the top of a couple of the raised beds. When I say "mostly finished," I mean that everything will fit through 1/2" sieve holes, but not necessarily 1/4" holes, due to tiny live oak leaves that take forever to completely break down. I didn't think about the nitrogen-robbing properties, though, of compost that is not *completely* finished, so that may cause a little problem. It's just sitting on top -- should I scoop it back up? Or let it be?
For the other beds, I bought some mushroom compost, and have laid that out on top. I'm resisting the urge to dig it in, but not sure if I can plant directly into straight compost (??).
My "soil is probably tired" comment comes from a couple of observations:
-- the soil level has gone down over last year. I never step on the raised beds, but I imagine some compaction may have occurred as the soil settled, but my bigger concern is that the organic stuff has disappeared.
-- I used a store-bought soil tester last year and it was at the dividing line between "good" and "low" then. I don't imagine it's gotten better, although I need to find it and look again. It's never been in the solidly "good" range.
As a last thought -- one raised bed that I made last year has always seemed heavy to me. That's the one I added my homemade compost to, hoping to give it better drainage. I may have traded "too heavy" for "nitrogen deficient" though. It's always something, lol.
Hi, Linda. You and I were typing at the same time. Your list looks a lot like my list, except for a couple of items. I forgot to mention a couple of bags of Perlite. (I confess, I love Perlite!).
I too had poor luck with peppers this year, although I've never had a good year. This leads to a question: Are certain crops good bellwethers?
If "X" doesn't grow, your soil is probably "Y." Of course it's never that simple, is it.
For the record, I've never grown a decent radish, chive, carrot or pepper.
NicoleC and RickCorey_WA:
To dig or not to dig...that is the question! I heard the local gardening show on the radio recently, and that guy said to not dig up the beds or it would ruin the living web of fungi, etc., beneath it. So my first thought this year was to try to honor that principle and just throw some compost on top and be done with it. BUT, of course, that idea falls apart for the raised bed that feels too heavy. I just about have to dig the compost and pine bark in, in order to add that fluffiness. Right? So I'm thinking that I will do that, but leave the other beds alone. Decent experiment maybe.
Thanks. I am enjoying this discussion, and hope it's useful to others as well.
I hear yah on that "heavy bed", I have one too. I know adding the chipped PBFs will lift it considerably, and help the drainage, too. How do you incorporate your perlite and vermiculite into your RBs, or do you?
My best producing bed (RB #1) was originally filled with a customized RB formula, that Tapla recommended, a mixture of 4 parts PBFs, 2 parts peat (I used Miracle Grow), & 1 part coarse perlite. Since that time, I've thrown in some sharp sand and composted garden soil, since the bed never had any real soil in it and I was going for some organisms.
I think I may end up digging out RB #2 (where the bell peppers were), to check on whether there's a drainage issue under that bed. I got a lot of yellowed leaves on those bells, and not sure it was drainage or nutrients...
>> To dig or not to dig...that is the question! I heard the local gardening show on the radio recently, and that guy said to not dig up the beds or it would ruin the living web of fungi, etc., beneath it. So my first thought this year was to try to honor that principle and just throw some compost on top and be done with it. BUT, of course, that idea falls apart for the raised bed that feels too heavy. I just about have to dig the compost and pine bark in, in order to add that fluffiness. Right? So I'm thinking that I will do that, but leave the other beds alone. Decent experiment maybe.
I totally agree with both of you. When you turn and break up every clod into powder, you do disrupt fungi and soil structure and air channels - IF you had any to start with!
There is probably little need to till and break up excellent soil. You can even do harm, because you have some soil structure to be harmed!
However, "heavy soil" just becomes "pudding" if you don't fluff it up every few years. Turn gently, break up what's necessary, like clay and sticky lumps. Then work into that nasty clumpy stuff as much compost as you can afford, plus fibers or grit like very small pine bark fines while just damp enough to FORM clods or peds,
When it seems to be as fluffed up as possible and it's clumping into peds but not pudding, firm it down barely enough to discourage the peds from dissolving, but NOT so firm that you press the air voids out of existence.
Kind of like an omelet or soufflé.
I don't know for sure what keeps the clay and silt from leaching right out of the peds, but I suspect compost (organic matter, humic acids, very fine fibers?).
Something has to keep the peds 'stiff" enough that they don't deform and slump so that all the air space leaves. I like grit, coarse crushed rock, and tiny bark fibers.
I think the "no-till" people are right for their situation: namely, they have ENOUGH compost and organic matter to keep their soil lofty. Maybe they started with enough grit and sand and whatever that their soil acts like laom instead of clay. I wouldn't know. But if you start with raw clay, and can't afford 6 inches of compost one-time plus 2-3 inches per year to make "great" soil, maybe some delicate tilling is helpful in maintaining "fair" soil instead of "very poor" soil.
That's my theory, but I only have "pretty fair" soil in most of my beds. I know that many people with "great" soil disagree with me and never need to till.
>> I didn't think about the nitrogen-robbing properties, though, of compost that is not *completely* finished,
I think it depends on how "lean" your pile was. If it was mostly browns, and kind of stalled while half-digested, you might be right and it is just waiting its chance to steal N from somewhere.
If it was a fairly "green" heap and the leaves are just still there because they are so hard to digest, go ahead and leave the compost in place. It will provide as much N as it absorbs.
Besides, this is a case like top-dressing with wood chips. Anything on TOP of the soil can't steal N from below the soil surface. So there's no risk of N depletion. In fact, N will leach out of the top layer and enrich the soil, leaving the dry or tough C materials behind on the surface as a mulch. That's practically perfect in every way.
>> For the other beds, I bought some mushroom compost, and have laid that out on top. I'm resisting the urge to dig it in, but not sure if I can plant directly into straight compost (??).
I would turn it under or scratch it in with a cultivator, to mix the "food" with the "eaters" ASAP, and also to amend my heavy soil ASAP.
You could preserve or improve your tilth and "loft" by using a garden fork like a broadfork: just tilt it a little and let some compost trickle down into the openings, but don't beat up the clods and peds into powder.
With my soil, in the hungrier beds, I have to lift and separate every year or two, or it reverts to clay. In the best beds, top-dressed compost does seem to trickle down and keep the root zone happy. Burt I still find, when I dig, that the soil 18" down has lost its structure through compaction, starvation or illuviation.
>> the phosphorus and potassium doesn't redistribute itself so well. When possible, they should be mixed into the root zone to make them more available.
Good point. I stand corrected.
>> if you have good tilth, tearing it up and mixing things in will destroy it.
You're probably right, but I'm used to very heavy clay and marginal tilth, and then very poor tilth when the compost is all digested.
I think that the need to fluff the soil back up, and/or turn things under, is reduced or maybe eliminated only if you have access to lots of compost.
I don't really know what would be "enough" compost since I never have that much.
Linda, I would put some of the aged, shredded oak leaves into RB #3 to provide maximum organic matter. maybe composting them first would be better, but if the soil is shrinking, that suggests to me "compost depletion" and soil getting ready to revert to clay.
I'm going to use a broad fork when I incorporate whatever into my beds...don't have a tiller of my own, and I agree with disturbing only as much as I have to.
Fact is, I've never had much in the way of organics to create a bio culture? in my beds. To date, I've found maybe 5 worms between the three raised beds...that tells me a lot about my organic makeup...there IS no organic make-up!!!
And, yet, I continue to harvest wonderful produce...
A few years ago, I scored a huge bag of Perlite as a Mother's Day present -- had to travel across town to get it. Because of that, I did use quite a bit of perlite in my first 2 RBs. Since then I've only found small bags. I did add Perlite for RBs #3 & #4, but for the last two, I ran out so continued without it. Guess what, those beds are the heavy ones. (duh).
I've been able to dramatically improve my soil texture with top dressings of 3-4" composted leaves from the city compost pile. (Free). Semi-composted, I should say; there are plenty of semi-intact leaves. The stuff seems to be a worm magnet. After the first year you could see the difference up to 6" down, where my soil turned from it's rocky orange limestone to brownish-grey. The compost on top was completely gone, but worms *everywhere.*.
I would not underestimate the power of the worms and microfauna to pull good stuff down into your soil from top dressing, but it takes time. And, of course, healthy life in your soil which is sometimes hard to find in residential back yards. (Or farms, for that matter!)
I agree with Rick that loosening with a broadfork isn't a bad compromise.
>> 3-4" composted leaves
>> After the first year you could see the difference up to 6" down,
That sounds right to me: 50% - 67% compost will do soil a LOT of good, especially if it is already open enough for water and air (and worms) to perk through it.
The benefit was not noticeable 12" down, which might have only been a matter of time, or might reflect my belief that in really dead, hungry clay, the first 12" of soil needs around 50% compost to start looking good (say 4-6" the first year and 2-4" per year afterward).
If you can only apply 1 inch per year, you'll still be trying to manage heavy clay soil years later.
>> composted leaves from the city compost pile. (Free).
All our yard waste goes to "Cedar Grove Compost". The stuff that they sell for $35 a cubic yard (undelivered) seems to have 90% to 95% wood products, with barely enough compost and biosolids to give it any odor. And $35 is too much for a yard of wood shavings.
When I went to pick some up from a "dirt yard", I had to ask which pile was the compost. He pointed at the pile I had just assumed was coarse sawdust. I gave him the hairy eyeball and he admitted that he called it "mulch", himself.
When I get more desperate, I'm going to line my trunk with something heavy, or as many 5 gallon buckets as I can fit in a Ford Escort, then trundle off to the municipal waste treatment plant for free biosolids (Class A, certified pathogen and heavy metal free). The Scheissemeister there sounded like someone I could trust, and he's eager to give it away to someone other than Cedar Grove.
He seemed lonely, poor guy!
But he warned me that it wasn't very "de-watered" and I would have to shovel it myself.
There are advantages and distadvantages to tilling or not tilling and each has benefits.
I don't see any problems with cultivating the soil or turning it over with a shovel or pitchfork on a small garden area, especially where you are constantly adding organic matter. If done correctly you can equally distribute nutrients, organic matter etc in the root zone. You can aerate the soil which will increase soil microbial activity and provide more nutrients. In heavy soils it is very helpful to loosen up the soil and incorporate straw or organic matter or even some sand to prevent compaction.
There has been a huge debate in large scale farming of tilling vs no-tilling.
Pro's of tilling:
Increased soil aeration, non chemical weed control, increased decay of organic matter which releases nutrients, more uniform topsoil layer, better distributed fertilizer, quicker decay of crop residue which reduces plant diseases and insect survival.
Con's of tilling:
In tilling you have more soil erosion, you can compact the soil, you can stir annual weed seeds and promote their germination, you dry out the soil, speed up decomposition by increasing aeration which lowers the soils organic matter content. Tillage requires wear on tractors and implements and cost of fuel.
No till...directly planting into previous crops residue has become very popular in the last 20 years. Over time no-till favors increased soil organic matter content, reduced weed pressure(shifts more to perennial weeds) though these systems require more frequent use of herbicides to control weeds as cultivation is not an option. No-till systems have very little soil erosion and better water penetration and retention in the soil. They do warm up slower in the spring. They have less soil compaction problems and are more fertile. Some of the downsides is that a special seeder is needed and sometimes plant residue can get too thick on the surface. One detriment to thick layers of mulch is that insects and plant diseases can be harbored there so sometimes no-till systems encounter more diseases and insect problems.
The benefit was not noticeable 12" down, which might have only been a matter of time, or might reflect my belief that in really dead, hungry clay, the first 12" of soil needs around 50% compost to start looking good (say 4-6" the first year and 2-4" per year afterward).
I haven't dug any deep holes lately under the compost/mulched zone, so I don't know how far down it goes now. But this site is badly eroded; there is no top soil just subsoil; there's a limit to how much living space there is for even deep dwelling worms and such. A legacy of the southeast's destructive farming practices 100 years ago. A rock base layer is not going to turn into lush soil no matter what you do.
So in the veggie garden I've imported a lot of materials.
Last soil test for the garden, the lab's coversheet told me to lay off the municipal leaf compost -- too much phosphorus. My manure sources are no longer safe; they are contaminated with persistent herbicides. My mushroom compost source has dried up, too. I need about 4 cu yards this fall to finish filling beds and replace some lost matter; I haven't decided what to do yet.
>> composted leaves from the city compost pile. (Free).
They stopped vacuuming up leaves in the fall a couple of years ago, so it's a diminishing resource now. Twice a month there's a loader there and donations to the master gardeners are requested, so for $5 or so you don't even have to shovel. Seriously... people were supposed to rake their leaves into the ditch and then this big vacuum truck would come by and suck them up and take them to the compost pile. Budget cuts; apparently vacuum trucks are expensive to maintain. Now people are supposed to put them in bags and leave them by the curb and a truck comes by for the landfill. ARG! I pick up some of those bags for my compost pile, but it's all oak trees in this neighborhood so they take forever to break down. (Of course most everyone still rakes them into the ditch and wonders why the drainage pipes all back up.)
The plants in the landscape beds *love* the leaf litter. It's what they'd get in the wild anyway, most of them. I'm not sure what I'll do for the landscape beds when the pile is gone. Pine straw or arborist wood chips, perhaps.
I ripped the tomato vines last night, and turned the bed with my broad fork. The soil is so loose, I can dig holes without a trowel...
Then, I did a really, really, really, really (really, that many reallys...) stupid thing...
I went to the pile of exposed-to-the-elements shredded oak leaves laying in the side yard. And, instead of just shoveling some of those lose leaves into my wheelbarrow and over into the RB, I grabbed a contractor-sized bag of the NON-shredded oak leaves (still from last year) and dumped it on top of the bed. Cause, duh, it was easier to haul the intact bag than shovel up the loose leaves spilling out from burst bags...
Then, as I stood looking at all those hard leaves and acorns on top of my raised bed, my brain kicked in! I could'a had a V-8! But, I digress...
It was after the last acorn hit the soil that I could've kicked myself for being so dense!
I looked over at the site of the other two RBs that were surrounded by pathways of lovely, crumbly, rich black, BROKEN DOWN oak leaves, at least 3" deep, and realized that I should've been shoveling THAT into the RB, and replacing those pathways with the fresh leaves...
So, after dark, as I lifted the last of the leaves off of the raised bed, and snatched up the last acorn, I thanked God for the strength to undo the dastardly deed I had done...
I was moving too fast, in anticipation of having rain this morning to water the leaves and the bed, etc.. Of course, no rain...I KNOW I'll never make that mistake again, LOL!
Oh, but your lesson has taught US! (me, anyway!). So it's all good.
Seriously, even if your thought process was too slow to save you from all that added work, it was still ahead of mine. I'm going to go look in my own yard for those places where the leaves have naturally broken down now!
I agree with everything you said. I would just add that different circumstances and different soil types shift the balance of factors in different directions.
And maybe "low till" or "infrequently till" is advantageous for some circumstances.
Too bad there is no light-weight power equipment to perform rapid large-area broad-forking with minimal compaction. Something like the lawn tool that drills holes into the turf to "open it up".
>> no top soil just subsoil;
I'm trying hard to find a silver lining: at least if it is sandy subsoil, you might have good drainage.
>> I need about 4 cu yards this fall to finish filling beds and replace some lost matter; I haven't decided what to do yet.
Sympathy! I have the same problem on a small scale: not enough compost for the clayey RBs I've already made, and two new spots for beds waiting for me to make them some soil. It's time to experiment with "cover crops" in beds that are just 2-3 square yards each, and some of them shady.
>> I was moving too fast,
But at least you were DOING it. Sometimes I get so far behind that I give up and lose an entire season of planting.
We do that all the time while developing software.
"We need to save several days in order to meet a deadline!"
"Gee, why have we been correcting so many mistakes that now we several months behind?"
We have a set response for when managers tell us that they need something "done right away, we need it really badly".
"OK, just HOW badly shall I do it?"
>> Compost is problematic in this dry climate
How do you get any organic matter into your beds? Top-dress with mulch and let that break down over months or years?
I have a dry summer, so my heap always has a layer of dry stems covering a moist interior. But I water the heap every time I water the beds. Now that I have sprayers and drippers on the beds, I need to put a shrub-waterer on top of my compost heap.
Compost is problematic in our dry climate because compost requires moisture to break down - things here dehydrate/mummify instead of composting naturally. One simple solution is to build the compost pile where the sprinkler system for the lawn or the soaker/drip system for the garden will water the compost pile, too. I have my pile at the corner of the lawn adjacent to the garden.
Even then it is only semi-composted, so I sieve the material through hail screen - Then I use the courser compost as mulch and let it go another season.
Anyway, I said my parents never used compost. I guess it would be more accurate to say they did "sheet composting". They used traditional rows with paths between. Small scraps were buried directly into the path - when ever we got a "shovelful" (usually daily), in it went. We worked down one path and then started on the next.
I am seriously considering going back to my roots and shredding my fall cleanup and turning it directly into the garden. I think it would break down as well, if not better, than trying to compost during the winter.
The pros and cons of till/no till discussed by drrobarr above were well expressed. I've got a tractor, a tiller and every kind of hand equipment. The tractor is not allowed in the kitchen garden. The tiller is necessary here and there for two reasons. One is because we have heavy clay soil that after twenty five years of amending will still turn heavy if loads of organic matter are not continually incorporated. The other reason is tree roots from the surrounding woods that abut the garden can cover the immediate subsoil in no time. I can go a few years without tilling but more than three and I'll have tree roots within inches of the surface. For that reason I must both till and periodically deep shovel to get rid of roots. Also, 'cause I garden on the side of a mountain, there is the perpetual granite heaving. That cause other issues.
I do a combination in my 15 x 45 foot veggie garden, with Virginia Clay soil. This past Spring, I bought a "cultivator" from Sears, and it is PERFECT for my needs. I hand-dig the hard clay, break it up at bit, then get that cultivator a'goin', and I have at it! It breaks up that clay beautifully, but it is NOT a deep digger - I AM! Hahahaha...
After I hand-dig, break up manually the largest clods, and mash it all up with my cultivator, I throw compost, manure with sand, top soil, and "Clay Cutter," generously on top of that clay. Again, that cultivator comes out to play! It really blenderizes everything together, and what a nice finished earth I have for my veggie babies.
I doubt seriously that any ONE method is correct. After all, just think of it, Mother Nature makes "microclimates" even in my little veggie garden, so She is not happy with just ONE climate for growing crops...why should we be satisfied?
As for myself, I'm going to plant some seeds tomorrow...if the rain allows.
A few have posted that they add "sharp sand," and someone mentioned "grit."
I don't see either at the big box stores. I see playground sand, and I see some that is just marked "sand" and is marketed near the pavers as a sort of loose grout around pavers when making a patio.
I also see bags of crushed granite, which are pieces that could be anywhere from dust to pea-sized. Is any of that something that could be useful??
I bought some of the paver type sand in the past and added it to a couple of beds, but it just felt like the soil was getting heavier (and why wouldn't it?). So do I really need it at all? Or is that just for certain types of soil?
Sharp sand/builders sand is a courser grit of sand. Play sand is much finer, powdery.
I add sharp sand to aid with structure and drainage. Smaller grit sand will hold the water molecules and compress, threatening to drown roots. Because of the larger surface area of sharp sand, the water rolls off.
Sharp sand crystals almost remind you of tiny rock candy, but not quite as big as the rock candy crystals...
I buy mine at the dirt yard...down here it's called sharp sand, torpedo sand, builders sand...
Granite sand is good, if it is more sand than gravel. Sand does not replace organic matter, I know of someone who mixed too much sand into their clay and got it too sandy (which made it too hot and dry).
If you have several types of sand to choose from, I would take a magnet along. Granite sand should have "iron filings" in it, it will make a magnet fuzzy.
Around here, we get things like sand and gravel at landscape supply yards, not at garden center stores. It is sold by weight, bring your own bucket, tub, or pickup truck.
Wherever I've been able to see the inside of a bag, anything with the word "sand" has been mostly finer than I wanted.
I want only a little of my "sandy" amendments to be finer than 1 mm, which I think is technically "fine grit" rather than "coarse sand".
But even the bags of "coarse sand" that I've found were a mix that was more than 50% fine or medium-fine sand.
The perfect size for me (1-2 mm) was #2 chicken grit (granite, not oyster shell). Sieved so that NONE of it was fine or dusty, nice and irregular grains. But pricy, if I recall.
Double-screened "crushed rock" or fine aggregate would be perfect, but I don't have a good way to carry a cubic yard home with me. I would shop for it at a place that advertises concrete products or mixes, maybe masonry supplies.
The term "double-screened" should mean that it passed through a 1/8" sieve or 1/16" sieve but not through a 1/32" sieve. I think that's what makes it expensive.
So if you can find some other crushed rock product that is mostly the size you want, maybe take the fine with the coarse.
>> bags of crushed granite, which are pieces that could be anywhere from dust to pea-sized.
Great! Crushed granite is great, or any other crushed stone other than lava. Lava will crumble to dust too quickly.
Some soil gourmet pointed out that mixed rocks, like river gravel or glacial till is the very best, since a mixture will provide more variety of micro-nutrients. (I personally think that's gilding the lily unless you're hunting for rock POWDER or rock DUST as a source of micro-nutrients).
You have to decide what sizes of sand or grit you want, and how much you can pay to get that exact size and no other size.
Probably it is best to accept that cheaper mixes will have 50% medium sand, and accept that.
very fine sand- - 1⁄16 mm - ⅛ mm
fine sand - - - - - ⅛ mm - ¼ mm
medium sand - - -¼ mm - ½ mm
coarse sand - - - - ½ mm - 1 mm
very coarse sand - -1 mm - 2 mm
(I thought anything above 1 mm was grit!)
>> I bought some of the paver type sand in the past and added it to a couple of beds, but it just felt like the soil was getting heavier
Yup. Sand and grit by themselves cannot repair clay soil. It really truly needs a lot of compost, and more compost or organic matter added every year. (Perhaps as a top-dressed mulch. Hungry worms will mix it down for you.)
Paver sand might not have any particles bigger than 1/2 mm or 3/4 mm.
However, once the clay DOES have almost enough compost to form crumbs, clods or peds, I think that very coarse sand, or relatively fine grit, DO contribute to the soil structure, hence drainage and aeration. Also bark nuggets and bark shreds with small dimensions around 1-3 mm and the long dimension as long as you can get,
But the organic matter is totally necessary. It has to be well mixed with the clay to make it something other than sticky and squishy (easily deformed). Over time, worms and frost and water will do the very finest mixing, but you may have to "fluff up" the soil yearly until that is accomplished.
Maybe (I'm not sure), there is also a purpose for fine and medium sand. Not to make the soil structure directly by "sticking out its elbows" and mechanically creating voids, but rather as a way of making tiny peds and crumbs stiffer, hence less malleable, hence less likely to deform and flow into voids and air gaps, clogging them and squeezing all the open pore space out of the soil.
Also, maybe fine and medium sand make it easier to mix clay thoroughly with compost, by making it more friable. Like dusting sugar crystals onto microscopic gummy bears - they aren't as sticky.
When clay is just sticky, two very tiny clay balls that touch will always stick together and make one big clay ball. When you try to mix that with compost, you just have big sticky balls of clay.
MAYBE when the sand is mixed with clay, the sand grains on the surfaces of tiny clay balls keep them from sticking together as easily and tightly.
Now you can rub it and force it through 1/4" mesh or finer and break it down into even tinier clay balls that will take up the compost and "dissolve" into really tiny clumps of compost-and-clay that now have the ability to form peds.
Maybe making the clay more friable lets you break it down into smaller clumps that mix better with compost.
Pure speculation on my part, except that I have noticed clay become more friable when mixed with sand.
I guess I should revise my post
Here in the west where we have alkaline soil, you do NOT want to add more lime, whatever the size of the grit. So maybe one would need a magnet and some vinegar. If vinegar makes it fizz, it is okay for acid soils but not for alkaline.
By the way, my soil is basically clay from broken down limestone shale - and it fizzes when you pour vinegar on it. Not all alkaline soils will do this, so it isn't actually a pH test. But it still amazes me to think about the parts of the country that routinely buy and add lime to their acid soil!
yes big difference between east and west USA...humid vs arid and soil alkalinity/acidity. Our soils are acid here in PA mainly because of the high amounts of rainfall 40+ inches per year of slightly acidic rain. So liming our soils periodically can help raise the pH closer to neutral. A neutral pH is the range where most nutrients are plant available.
I'm slow getting back to this thread, but I so appreciate the discussion! Thanks for further thoughts on sand, grit, crushed granite, etc. Now I know that the sane I bought is builder's sand.
On the alkaline comment, like pollengarden in Pueblo, here in San Antonio we have soil with pH of 8 or 8 point something, as a rule. Plus most yards here sit atop a limestone ledge, which is why I use raised beds.
Now with my own mix of soil (combo of purchased stuff plus my own compost) you'd think pH wouldn't be an issue but I think I'm understanding that even the rain here is alkaline, plus compost made of plants grown in this area (grass, leaves from my yard) will make it more alkaline over time. So no adding lime for me!
Anyway, it's just something to keep an eye on. I read a couple suggestions to add granulated sulphur but I haven't gone down that path yet.
Yes, sulfur is a common acidifier. Sulfur combined with water makes sulfuric acid - handle with care. Protect your eyes and respiratory system from any contact.
It is the Sulfur in onions that makes them keep well - and makes your eyes water. The sulfur in the onion combines with your tears to make weak sulfuric acid. That why mild onions like Walla Walla and Vidalia don't make your eyes water but don't keep worth a darn - they are a naturally low sulfur onion grown in low sulfur soil.
Since the soils here a High in "Free Lime" (available lime), adding acidifier does not help much - the acid dissolves more lime and soil just fizzes until it returns back to near the original pH. Adding organic matter does help, it increases the percentage of non-lime soil. My soil is high in salt, too, so I can't add manure (except perhaps poultry, since they don't eat salt).
I am slowly double digging all my beds, adding organic matter deeply, AND sieving out the little limestone rocks.
To the beds that are directly in the "dirt", I add organic compost that includes pine bark fines, peat, sharp sand, greensand, rock phosphate, azomite (small amount), bone meal, and blood meal. Now it will depend on the area and what I am planting, to add anything else. I did add some manure for my pea beds as well as perlite since these beds have a tendency to compact. This particular area
has been worked several times and is particularly sticky hard clay, but I can see that it has improved a bit.
Sometimes it takes years, unless I just dig out all my dirt and replace it with a soilless mix, which I did for part of my shady bed. It is doing wonderfully and is lush and green with huge leaves.
We live in the forest and lots of tree roots had to be removed for that shady garden. I dug 2 feet down and took all the soil out...including those roots! It took a while, last fall and then spring. I just dug a little at a time, since I am an old lady now.
Rain most places is acidic. Some because of the pollutants in the air from emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. But also as water falls it comes in contact with atmospheric carbon dioxide, or CO2, which is a weak acid and forms carbonic acid.
It is possible for rain to combine with other substances in the atmosphere that will increase the alkalinity of its pH, such as suspended soil dust(which could happen in San Anton), but most rain water ultimately has a pH between five and seven, making it slightly acidic.
If you irrigate, the pH of the water you use will have a huge impact on your gardens soil pH.
Adding sulfur to a calcareous soil is a challenging proposition. Many calcareous soils are highly buffered and it would take alot of sulfur to reduce the pH. I do use sulfur here to treat the soil around my blueberries and have had success. It is stinky though.
Soil is the stuff your plants grow in. Dirt is what you sweep off the floor.