How does this look for Container "Mix"?

[ID jit]

Will be the first person to admit that I am self educated just enough to be good and dangerous to my plants. Looking to grow strawberries in SIP's or earth boxes or wicking beds - can't decipher the differences between the three.

Does this look adequate by itself or do I need to add something (beside some slow release 15-30-15 fertilizer)?



This is just strait muchy compost. Can compress it if I squeeze my fist tightly, and it sounds and feels like squeezing a very damp sponge. It will expand back out a bit when I release the pressure but will retain its shape, Can squeeze liquid out of it if I really try. Over all it is fairly black, earthy smelling, spongy and full of little aeration volunteers... pretty much on the lines of wet peat moss in consistency.

I have a lot of this, which is a good thing because I am going to be needing 80 gallons of mix by the end of the project. Am too inexperienced in this to know what, if anything, to add to this base to make the best, long term mix for the containers. Would like to keep the stuff fairly light so the container don't bow out on the sides and keep the "soil" dry enough to avoid fungi problems with the plants.

Would YOU use it strait or add stuff to it?

[ID jit]

I also have a boat load of this readily available and free - garden soil.


This is local green/grey, fine glacial till with a long history of organics being worked into it. Compresses in my fist with no sponginess, holds shape well, breaks apart far more difficultly than the strait mulchy compost. Is Blacker than the image shows, like the mulchy compost. Has a grainy, sandy feel to it and most of the pea-sized and larger stones have been picked out of it over the years. It drains really quickly and is hard to get water to puddle on it for more than 30 seconds with a garden hose even when it is super saturated. It is much more dense / heavier than the mulchy compost.


Garden soil on left. Mulchy compost or right.


Just not sure how to proceed form here and looking for advice.
Thanks much

[ButterflyLady29]

Garden soil and even straight compost are really a bad idea for containers. The reason is that they tend to settle and pack when used in containers. Peat moss or (my preferred medium) coir fiber will help lighten the mix and allow better drainage. Either material will be pretty expensive in the quantities you'll need. Another option would be to mix in some potting mix but again it gets expensive. Unfortunately you do have to add something to keep the compost from packing down and killing your strawberries.

Don't try to cut corners and mix in bagged garden soil. I made that mistake one year and it mashed down and held water and stunk! Not even weeds grew in those pots.

[ID jit]

I hear you on the coir, but I am not getting 25 gallons shipped in and I can't find it locally. That may change when the garden shops open up in the area next spring. As it is, a 3 ft^3 bag of basic peat is going to be a 2-3 hour ride for me considering the time I will be able to make the trip.

Took another, different look at the container mix recipes I have found.

1/3 food
1/3 drainage
1/3 lightness and moisture retention

I have a lot of muchy compost that has the sponginess of peat. This covers the food third, and will hopefully act as a natural slow release nitrogen source and kind of doubles as a moisture retainer. It will collapse and be consumed, but hopefully get me threw a season. Have pretty much decided to recruit some red wiggler volunteers out of my compost piles to help with aeration and breaking down the mulchiness. Option would be to add more as the season progressed, maybe at the re-feed after the first flush of berries.

Right now, I have a little experiment in environmental manipulation going on in my more active compost pile, the one I am still adding coffee grounds, veg scapes and the like to. Have a 5 gallon bucket with a couple dozen 1/4” holes drilled into the bottom full of what was mulchy compost and I keep adding coffee grounds and finely chopped up veg scraps to it and turn it over weekly carefully by hand. The couple hundred worms haven't left yet. The idea I had was if I make better food easier for them to get, they will stay in the bucket and and process the materials down for me, and if I mess up they are free to crawl out the top over out the holes in the bottom and do the same job in the compost pile the bucket is buried in. So far they are staying.

I have a lot of sandy garden soil. This cant be much worse that adding builders sand as far a weight/compaction is concerned and does have some food in it, and I know it drains well.

Picked up a 2ft^3 bag of large grain perlite (and a dust mask) last night. I know this will eventually wash out, but I wasn't coming up with any other viable options. Have eliminated the idea of vermiculite because it will probably recompress into flat mica flakes rather quickly.

Think it is time to make a few 2-litre SIPs and play with the art side of this and see what I can mix up out of what I have.
____________________

Was thinking about what I had on hand or have easy access to. Remembered I have a lot of black bog/swamp silt readily available. Have always been curious about this stuff. I know it is very high in tannins / tannic acid and compresses down very tightly. Nothing will grow in it when it is soggy, but the things growing on the edges of it seem to do very well. I am guessing there is a lot of nutrient in there. Wondering if I could neutralize the acid with egg shells and/or lime and end up with an additive which would help get my mix down in the 5.5-6 pH range where the strawberries want to be and get a fair amount of soluble nitrogen and trace elements out of it.

Any ideas?

[tomc]

Loess and silt have a too small particle size. Things in pots in this tiny particle size soil are going to die of anoxia.

Your chunkiest soil in above (top) photo with an equal volume of added sand is a much safer bet.

[ID jit]

The silt I have close at hand is a set of experiments for another season I think. I know nothing grows in it in its pure from, but I cant help but thing there has to be a boat load of nitrogen and traces in there is the tanic acid can be neutralized and the particulate is distributed enough not to sufficate everything. and crush the roots.

The mulchy compost, the chunky stuff, is what I want to use for the base of the mix. it has some peat-like qualites and is nutrient rich, and maybe a 50/50 or so split.

The other container of sandy garden soil is more like very fine bank run grave. It's pretty much devoid of clays and silt. It is actually a little more course than what I know as "builder's sand", more 3 dimentenial in texture, sort of. It is pretty much course sand with a lot of organics worked into it.

Get to experiment a little tomorrow I hope. 31 OCT I clipped off about 50 runners from some plants I had forgotten to prune down for the season. For some reason I started them rooting. Had five 6 packs and took the best 30 plant and finished to rooting in soggy soil. Sadly I grabbed the wrong 5 gallon bucket when I went to fill the 6-packs and need to re-pot the plants as soon as possible. Tomorrow I get to go root around my compost pile and excavate some garden soil in probably 30*F wet weather, mix something up and get the plants re-potted before the dirt I have them in kills them. Will post an image of what I come up with.

[ID jit]

Here is the first mix attempt:



2 parts mulchy compost, picked over
1 part sandy garden soil
1/2 part course grain perlite, which stated washing out with the first watering.
teaspoon per 1/2 gallon of 15-30-15 "Bloom Booster" or something like that.

Any comments?

Did realize that I do need to build some sort of compost screen if I am going to concoct 70 gallons of mix and that I will probably be better off effort/resource-wise just buying a few bags of builder's sand.

What today showed me was that I am probably back to
1/3 screened compost
1/3 course sand
1/3 peat or coir.

Good news is the plants I started rooting 31OCT are not going to get crushed and suffocated by my wrong choice of "soil" the first time around. Was surprised. Most of the plants still had some decent root structure. A few on the other hand barely had any and it is pretty much right back to rooting. If I can get 12 decent plants out of the 30, I am going to call it a win.

[digitS']

I have a lot of pea gravel in my glacial till soil, if I screen out the larger rocks . My compost has a good deal of soil in it because I cap the pile with soil for the winter and may add a layer while building it.

In the past, my container growing hasn't been the most successful but it usually had to do with neglect. I've gotten better!

Using my own compost in potting mixes for larger/older plants has been guided by the National Center for Appropriate Technology.

If you want some potting soil recipes, scroll down past all the source material to Appendix 3:

Potting Mixes for Certified Organic Production

Steve

[imafan26]

Your first mix attempt would be o.k. if you don't get a lot of water and depending on the kinds of containers you have. If you water or it rains a lot, you need more perlite. Hint wet the perlite and the media before you mix them. Perlite is light and floats to the top otherwise. If they are slightly wet to start with, they stay mixed better.
For myself, compost in the garden with soil no more than 20 percent of volume in clay soil. In sandy soil, it can handle more. Clay holds too much water and compost compounds that issue.
For clay soil One part soil, one part compost, one part drainage material (builder's sand or cinders in my neighborhood). It is better to not to sift the soil, soil particles of differrent sizes stay looser longer.
For a potting mix if you are a heavy waterer or in a wet climate. One part peat moss or coir, one part perlite, a handful of vermicast in a five gallon bucket. 50/50 peatlite will drain very well and you can water it every day. If you need it to dry very fast for succulents use a porous pot like terra cotta. If you have plastic pots, it dries slower.
For a potting mix if you want to water less or if you live in a dry climate. One part peat moss or coir, one part coarse compost, one part perlite or vermiculite. Peat moss and coir are hard to wet initially, but hold a lot of water once they are wet. Compost will also hold water well. Again the more porous containers dry faster than solid ones.

More drain holes the better and nix the saucers.

I do not use anything more than a handful of vermicast in my pots, because one compost and especially manures kill most of my plants. It is too alkaline, holds too much water, and makes a very dense soil. Not enough air spaces.
Organics purpose is to feed the soil, potted plants don't do much for the soil unless you recycle them later. Small pots do not contain enough microbes to support plants in pots organically. You have to continuously feed them. If you are feeding the plant and not the soil, it is not really organic, since the soil in the pot cannot support the plant without continuous inputs. Nutrients in organic fertilizers are not readily available to plants and must be converted by soil microbes to a form that the plants can use. There is not a large soil community in a pot and they will feed themselves first. It is not sustainable if you have to continually add fertilizer to support the plants. If you want to be organic, it is best to do that in a raised bed or large enough pots that contain a minimum amount of soil to be self sustaining. Organic does not mean no pesticides are used. Organic pesticides are still toxic, they can be misused, they just don't last as long. Organic byproducts can still be environmentally damaging like manure runoff into waterways and organic fertilizers like manures and animal byproducts may contain pathogens harmful to humans.

[ID jit]

DigitS', Thanks for the link. The mix thing is something I am struggling with because there are so many variables and options. I'm try to make what I need out of what I have readily available and purchasing as little as possible. At least I am past the compound ignorance stage and know how clueless I am about how to concoct the best mix out of what I have.

Imafan26, thanks for another education/spoon feeding.

What I am working toward are strawberries in SIPs, 6 plants to 9 gallons of mix. Very much want to avoid having to swap out 70 gallons of mix yearly because the perlite washed out or the peat decomposed or re-compressed. Also want the mix light enough to avoid bowing out the sides of the plastic totes. The more I research, the more I realize I am sort of trying to find uber-unobtanium.

What I am trying to decide on now is if I need 1/3 peat/coir or if I can get away with a 50/50 mix of mulchy compost and builder's sand with course grain perlite.

Pretty sure either option would work. Am just too much of a novice to figure out which would be better in the long run. The over all plan is to have 2 containers of this years plant not producing fruit and just getting strong, 2 containers of one year old plants, 2 containers of two year old plants and 2 containers of three year old plants. At the end of the season, compost the three year olds and start a new set of rooted-this-year plants. Then just keep cycling through the process. This should give me 36 producing plants with a set of replacement plants growing to full strength to replace the oldest set of plants which will be passing their prime.

Seems like a pretty solid plan to me, but then again I did choose my screen name here with care.

[ID jit]

Thanks for all the advice, insight and links.

Have 3 mix experiments going on right now with the runners I clipped of some sort of forgotten about plants on 31OCT.

Mix 1:
1 part sandy garden soil
1 part muchy compost

This stuff drains well when wet. Top watering takes maybe 2 seconds to pass through the media in the cup. The liquid I have coming out of the holes in the solo cups is a little darker and the same color as that funny tasting hot water stuff some people drink instead of coffee.

Mix 2:
1 part sandy garden soil
1 part muchy compost
1 part (per-saturated) course grain perlite

When wet, water runs through this stuff like it isn't even there. Liquid coming out of the bottom is just a little lighter than mix one, which makes sense – the water is spending less time in less organic matter.

Mix 3:
(the original stuff)
2 parts mulchy compost
1 part sandy garden soil
½ part course grain perlite.

This stuff drains a little slower than Mix 1, and the liquid coming out is darker, which makes sence.

I probably should re-cup some of the plants into

2 parts mulchy compost
1 part sandy garden soil.

Now the waiting to see how they compact begins. I have until mid April before I have to commit myself to a mix. Not the best design for an experiment, but it will show enough for me to make a good guess, I think.

What I would like to end up with is a container mix that is going to be its own little biosphere, with the soil all nice and alive and perpetually releasing nutrients to the plants. I feed the soil; the soil will feed the plants; the plants will produce some really nice berries. (Plan on stopping the cycle BEFORE the berries turn into soil food.)

What I would like to avoid is that halfway step to hydroponics where I am perpetually adding some form of fertilizer to a media concocted to hold some water and liquid nutrient and let the rest of it drain though quickly.

Oh, I should be collecting the probably nutrient bearing liquid coming out as drainage and using it to water the plants next time?

Short term this shouldn't lead to a salts and/or tannic acid build up, right?

[imafan26]

Short term it should be ok. The earthbox instructions say that you can add 3 cups organic fertilizer to the bin and it should be enough to last the entire time. The site did not specify the fertilizer. Unless you have a large container, it cannot be sustainable unless the plants in them have low nutrient requirements. Peas, mustard, greens, bush beans, some of the herbs, and turnips. Heavy feedeers like tomatoes, eggplant, peppers, cabbage, brussels' sprouts, broccoli,squash, corn, watermelon, corn and other large plants will need to be supplemented. Also beware that some plants do not like certain kinds of fertilizer or fertilizer that is not proportionate to their needs. Root crops need nitrogen in the first few weeks, but need a relatively low nitrogen when the roots start to swell or the tops will grow instead of the roots or the roots will fork. Manures can cause roots to scab. It is also important to make sure the soil volume is enough to support the plant. Roots need ample space to grow downward and sideways. Beets and turnips will push out of the soil. If the soil volume is not deep enough or too small to contain the roots, they will go out the drain holes into the ground or fill up the available space and if that is still not enough, the plant will stunt. Too many plants in a container will also be detrimental.