Some plants really need some sand in the soil especially since I live where we live has a lot reddish clay. However, I have been told that construction sand is not good to use because it makes the soil hard. I have noticed construction sand is fine.
That's begs the question, where do you get the right kind of sand?
I've never posted on this form before so "Hi". A word of caution, my ex-hub put costruction sand in my garden years ago, I think he was actually trying to help. Along with the sand I got root-knot nematodes. The extension agent said he had never seen them in this area before, because the native soil is so rocky. Anyway, they took years to get rid of, I don't know if they are in all sand but they were in that sand!
Welcome Lisa and thank you for that note. I guess I will go another route as suggested by marti. I have been a member since 2000 when there were about 2000 members (a coincidence). Now we have over 350,000 members! Amazing.
I found some good, coarse sand for sale by the cubic yard at a place that sells topsoil, shredded bark and compost.
I used to think that "grit" was the right name for coarser-than-coarse-sand but finer-than-fine-gravel. . But it turns out that there are international definitions, and, no, "there is no such thing as grit". Finer than 2 mm grain size is coarse sand, and over that is fine gravel.
But 1-3 mm seems to me the best size for mineral soil amendments for improving aeration & drainage. Maybe finer sizes help make soil firable.
In any event, clay by itself is terrible with or without sand added. Clay really needs organic amendment. And (I'm told) adding Ca++ in the form of gypsum (CaSO4) helps the minute clay particles bind together into larger crumbs, which helps tilth.
Once clay has enough organic matter added, I find that it also benefits greatly from sand, especially coarse sand. Maybe any coarse particles (such as decomposing wood chips or fibers) added to clay-plus-humus help firability and aeration.
I found this year that adding finely shredded pine bark (fine mulch) improved my heavy clay soil. Lightened it, made it more friable and less like pudding. As bark fibers break down, they will add organic humus, so that's win-win.
Corey, I'm still working on breaking up this clay of mine. I'm still getting woodchips/shavings to turn in and than maybe I'll try that coarse sand idea of yours. Most of my garden is going to be raised beds. We have so many maples here that digging is terrible. So I am composting in a large area for soil for the raised beds.
I don't know if it was the sand or the shredded bark mulch (I got both at the same time). But one of those had a lot of fine roots in it. at the time, I thoguht "they wouldn't sell sand and mulch with LIVE weed roots in it", but I may be naive.
I bought some compost and it was full of weeds. Won't do that again. I let the maple leaves fall here and I leave them. I also collect leaves around the neighborhood. They think I'm nuts!! Everyone around here throws their leaves away. Along with pine needles and anything else that falls out of trees.
As for the raised beds. I'm putting down some layers of old carpet and than the raised beds are made from old bathtubs, sinks etc. So that should take care of keeping roots out of the beds.
>> the raised beds are made from old bathtubs, sinks etc. So that should take care of keeping roots out of the beds.
Ah HAH! yes, that should do it.
It rmeionds me of a website that was really enthusiastic about bamboo, even the running kinds. They assured people that "it wasn't too hard" to contain. Then they gave examples that included power equipment digging deep trenches, and CONCRETE BARRIERS.
Being as how I am disabilied, I can not get down on the ground to garden, so by having raised beds, I can have my garden and enjoy it. I also have an old college professor's drawings on making raised beds using concrete bricks like they use to build walls, plus he coats the inside with tar and installs a bottom watering line. Helps save water. While the front of the yard will be carefully done with raised beds as I will not use the bathtubs and such in the front yard. There I am using natural things like logs to give me the raised beds.
The tubs and such will be used at the back of the property for starting seedlings and for veggies.
>> making raised beds using concrete bricks like they use to build walls, plus he coats the inside with tar and installs a bottom watering line
I never thoguht of BOTTOM wtaering!
I use paving stones, around 1" thick, stood on end. The corners dry out too fast, despite my heavy clay. I started lining the corners with the heavy plastic bags that compost or soil come in, to slow down evaporation. I like the idea of tar, assuming it doesn't hurt roots. What kind of product do you use for that? Driveway patching compound?
I also appreciate less bending: squatting is a challenge for my legs. I try to combine raising the bed with digging DOWN to create a low path around the beds. That aids drainage (deepr root zone) as well as reduces bending.
He made his 6 ft long and 4 feet wide .His instructions just say tar the inside.Than once water tight, he chips out a hole at the bottom of the 4 foot end at the ground level and inserted a 1/2 in to 1 in pipe that he had sealed at one end, put a hose connector at the other end and drilled holes in a double row the lenght of the pipe. To water, he connected a hose to the end of the pipe and turned the water on till he was sure that the whole bed was wet, than disconnect the pipe and it will slowly drain. You can also screww a cap on the end of the pipe to keep the water in. But do not leave enought water in it to make a bog garden. Not unless that's what you want. He said he would drain out about half the water, than cap the pipe. He made these in San Bernadino, Calif where summertime heat hit 90 to 110 during the day for the summer. With this method, he also cut his water bill by not having to water everyday. On a couple of the planters he also built a cover for them that worked like a cold frame during the winter and a green house during the spring.
>. On a couple of the planters he also built a cover for them that worked like a cold frame during the winter and a green house during the spring.
Yeah! I'm thinking along those lines. I wish my baby bamboo would hurry up and grow up so I can make hoops!
>> once water tight ... San Bernadino, Calif
Hmm, it almost sounds like he floods the bottom part of the bed! I wouldn't go that far. I'm more concerned about draining water AWAY than conserving. If I decide I don't like the "bags on the corners", maybe I'll just paint with waterproof paint.
But it's a new idea to me. Thanks, that stimulates thought! Like the people who bury a soda bottle cap-down, and pierce the neck and shoulders. Pour in 2 liters of water and keep walking. Let it water the roots much more gradually as water trickles out.
Like, bury a hollow reservoir IN the bed, say 2" PVC pipe with small holes along the bottom. Fill that pipe quickly and move on to the next bed. Let it trickle out at root level for hours. Hmm!
In this area I would not do my raised beds that way. San Bernadino is very dry and hot, no rain for most of the year, so he found that worked best for him there. Here in Ky, I'm figuring that I'll do it but water from the top and let it drain out at the bottom. If I build the block beds on top of the carpet, I do not need to seal the bottom, just the sides. The carpet will also kill all the weeds under it and give me a place to walk in the veggie patch and stay out of mud.
Corey, I like your 2 inch pvc scheme much better than the ground level one.
Now I'm envisioning a buried perf black plastic drainpipe installed in my garden bed and ready to receive rainwater collection from the nearby shed roof. Or a hose stuck in the end for a while.
>> In this area I would not do my raised beds that way. San Bernadino is very dry and hot, no rain for most of the year, so he found that worked best for him there. Here in Ky, I'm figuring that I'll do it but water from the top and let it drain out at the bottom.
This kind of thing is why I seldom take gardening "rules" at face value. Someone will say "you should always..." meaning "I should always ... BECAUSE, where I live, and they way I garden ...".
The "because" is the important and usefull part, not the rule by itself.
Lots of rain, little or no rain.
Rain in what seasons?
Cool, cold or brutal winters.
Cool, warm, hot or brutal summers.
Long or short frost-free seasons.
Springs that are fast or gradual, reliable or variable.
Time, energy and money available.
How can anyone give advice to anyone else without including the "why?"
I think advising is even harder because we don't always know WHY we have to do some things - or even how necessary they really are, even for oursleves. We just know "I did this, and it usually works out well enough".
I have added large amounts of sand [but not as coarse as pea gravel] mixed with a large amount of spaghnum peat moss from a local bog and this is mixed into a good clay/ loam soil, and then large amounts of organic matter is mixed into it. I love the result.
I've spent many weekends hacking and chipping dry clay with rocks and roots, using pick and mattock. I've always been told "never work soil wet or you'll make it much worse". And I ignored that once, decades ago, and made some poor soil into a useless moonscape of cracked, petrified ooze. Since then I have been AVOIDING touching soil on wet days - draping it with tarps if necessary to keep it dry.
Then someone from DG told me, "you know, if you sprinkle clay with a hose a day or two before, some water will eventually perk in and make it much easier to dig".
Well worth the price of a year's subscription to DG!
The surprising thing is that I never did sweat into it enough to soften it!
Sounds like that buried watering system is designed to work with the capillary action of the garden soil, just like in the patented Earthboxes and my homemade eBuckets.
Once there's water available below the roots, the plants can draw the water upward as they need/want to because of a "wicking action". The tip off is that he sealed the bricks with tar, effectively constructing a box with a reservoir in the bottom. All he did when he turned on the water was to fill the reservoir underneath the soil. The plants did the rest.
Actually, that is a pretty slick system, that does conserve water...think about it in terms of an Earthbox design...yep. That is really, really KEWL...
I reread those instructions, and I'll be darned if that isn't EXACTLY what he designed. An above ground EARTHBOX!
That is truly special!
And, ya'll need to try it, before yah knock it! I'd bet money that ya'll would be pleasantly surprised at what happens to your plants...
Linda, who sometimes takes longer to "get it" -- and then, there are times when she "GETS IT" immediately -- I GOT this one!
And, I'm soooooooooooooooo glad I did because I'm in the process of designing my backyard garden and building raised beds. I will certainly be thinking about how to incorporate the Raised Bed EB design into my plan!
It sounds as if some of you might be interested in a new forum that is just starting up on the subjects of square-foot gardening and raised-bed gardening. Here's the interest thread that has gone up on the Vegetable gardening forum.
Hi everyone. Been reading and found good ideas.
Rick when I got to my glacial morraine 12 years ago I knew that I would need to build all of my soil. So after playing with mostly clay I have found as you that compost in clay is the best as you have said. The other thing I have found is that shredded pine needles persist in the soil for over 5 years, making the soil wonderful for a long time. Also the addition of wood chips (rather large) mixed into the native soil with manure is the quickest soil ammendment to increase drainage. The wood fiber and shredded needles have made a home for vermiculture that provides long term soil ammendment. I have top dressed my raised beds and they origionally were this clay only with wood chips/N/and pine needles (whole at that time) still remain good soil due to the worms/bugs action bringing down the compost. Many beds are over 10 years old and the soil over 3 feet below the origional surface is remarkable. I think the road construction (Pine needles, wood, bark) provide soil continual enrichment with compost added each year.
I agree that slow-decaying, "solid" amendments like bark or even wood improve drainage and aeration. They may be better than sand, if you can keep replenishing them every few years, becuase they do add OM.
Since you say "glacial", don;t you also have some sand in there?
I used to add "Soil Pep" at $3 + per bag, because it had wood chips that I knew would last. However, where I added it thickest, where the clay was heaviest and rawest, became AWFULL. Maybe it was only fungus, and would have self-corrected in another year or two, but it seemed to repel water, look like alien life from a nasty SF movie, and plants hated it too.
So I replaced all that junk, removing it to a compost heap where it was valuable and WOULD decompose. . Now I add either composted steer manure, shredded pine bark, or (planning to) buy a cubic yard of "compost" even though I know has a lot of wood fiber and sawdust, but most of that composted at least somewhat. (Or haul biosolids in 5-gallon buckets in my trunk.)
Maybe I used too much wood in one place, or the clay made it anearobic, or it started with ZERO biota and nothing was going to make it usable rapidly, or I should have waited another year or two for it to compost. Or it needed a lot more N than I gave it. Or all of the above. But it makes me wonder how hugelkulture works!
Anyway, that bed is now around a C or C-minus where it used to be an F. Too heavy, poor drainage (but some), poor aeration (but some) and not enough OM (but some). It will grow things mostly-adequately, while I focus my energy and budget on other beds, the bring them up to "C level". THEN I'll go back around and turn more carbon inder everywhere, hopefully get to a no-till or "turn it every five years" plan.
But when one spade's-depth down is gooey pudding, I think my fork and spade mixing in what soil amendments I can afford are the right tools for this year.
Obviously, you have made "wood" work well in your conditions. I've seen some of your pictures! Maybe there is some limit like "10%" or "30% wood, or it should only be added where aeration is adequate.
I suspect that when soil is "mostly good" - and healthy, with reasobale amounts of life forms, air and drainage - it can accept a wider variety of things and make them work well. When all you have is gray clay, it needs to be improved a lot before it is healthy enough to accept and make effective use of things that would be GOOD for normal soil.
(After that bad experience with my first bed and wood-rich "Soil Pep", I started doing total soil replacement when I dug a bed down a ways, then raised up walls. I would move the clay and rocks out to a pile in the side yard where i could screen it and mix it with compost, sand etc. Then i would only move soil back into the bed that was within shouting ditance of deserving to be called "soil".
>> shredded pine needles persist in the soil for over 5 years,
That sounds good. The "needle" shape should be good for structure, increasing pores and channels. And they add OM, slowly.
No sand anywhere out west. Clay from glaciation of volcanic, granite, and many other uplifts. What looks like sand at our deep pools of blue water is truely clay. Sand comes from quartz and other schists. Michigan is nothing but sand the best to make soil drain it has NO mineral content like clay. It requires years and years of compost to grow a weed.
Now back to the issue at hand. I always started all of my beds with "mushroom compost" = horse manure and sawdust for 1 year mixed and mixed with tons of cow manure then rototilled it as deep as I could and then built raised beds over that. I started my home made soil at another site. Local loam (large clay) and added the same as above and worked it in and added an equal amount of wood chips and compost =10% total of soil volume. This sat for the year of soil prep in the native soil. Then I built the raised bed based on compost production.
This is the soil growing into a productive draining soil, before adding soil waiting in distance.