Is there any sense in doing the sifting? I mean, I just got constantly annoyed because I wanted fluffy soil without random twigs, wood chips and rocks which I then had to manually pick out so that there is no root obstruction.
But today I went on to move 4 pretty tall (6") peppers from the 2x2 square cells container to the bigger container (regular red plastic drinking cups with 5 large drilled holes) and what a pain! The plants are healthy but their soil is so soggy and the root ball is not intact at all, even though the roots were starting to poke out on the top. Once I carefully moved them to bigger containers and and filled it up with soil, I watered them and then just sat and waited...and waited...AND WAITED - it took 10 minutes for the little water that I added on top to get completely absorbed into the cups.

So does sifting out junk reduces drainage? How do you keep your soil fluffy and stone free? Am I just OCD-ing over nothing? I live in Southern New England, close enough to the ocean, so rocks/gravel are kind of a touchy subject for many of us here.

I just wish I could come up with reasonable ratios for stuff that's still under grow lights (last year I seem to have ruined tons of flowers by doing 33/33/33 of potting mix, cow manure and peatmoss)

Further, rather than trying to "fix" things, understand that potting mix is formulated to do its thing as is. Depends upon what you're growing as to which potting mix will serve you best.

I suggest you stick to one kind/brand, learn how fast it dries or stays wet, then always use the same kind because you know how it reacts.

You suggest sticking with one brand, but they do seem so different in consistency. Even though they are formulated for general purposes/any plant, I've noticed that plants have very different needs - for example, peppers really don't like peat moss, but they love cow manure and I believe that adding worm casting has significantly improved their germination rate this year. Ornamental millet also has poor germination rate, unless it's almost 50/50 starting mix with CM. It would be great to find one universal brand which will remove all the guesswork, that's for sure. Do you have any personal suggestions?

Thank you for assuring me sifting does more harm than good - it will save me lots of time this busy season.

To start seeds, I suggest you use the basic seed starting mix, then move the seedlings to potting mix after they develop a true set of leaves.

I fertilize as soon as the seed leaves open flat out, but I use a dissolve-in-water kind at quarter strength.

Worm castings are fine as fertilizer. But don't get carried away as too much inhibits growth rather than enhance it.

Have fun in your gardening but understand it's a live-and-learn kind of thing.

This illustration explains why you need to start with a large fraction of large particulates if you wish to take advantage of a soil that holds ample air in the root zone:

Use your mind's eye to picture what happens when you mix sand into a jar filled with marbles. You can fill a jar with a quart of marbles, but still pour a pint of sand into the jar ..... so did you ACTUALLY fit 1-1/2 quarts of material in a 1-quart jar? If you envision this arrangement, sand and marbles, what do you think the drainage characteristics of the soil would be? There's a quart of marbles but only a pint of sand, yet the drainage characteristics AND height of the PWT will be exactly that of the sand; the marbles would have no effect. The only thing that changed by mixing them together is the o/a volume of water the mixture CAN hold.

The same thing happens when trying to amend a fine soil or soil ingredient like peat/coir/compost/Hyponex/or other peat-based soil with large particles (like pine bark or perlite). This is precisely why adding a little bark and perlite to peat or bagged soils like Hyponex cannot achieve the (aeration/drainage) results possible when starting with a large % (75%+)of favorable size bark/perlite when building soils, and why adding a lot of peat or other heavy soils to the larger bark fraction doesn't work well either.

I think this is probably the clearest example (I've offered) as to why particle size is so important to how container soils function.

For a better understanding of how soil/water relationships affect growth and vitality, follow the link I left below.

AL

Thank you for your response. It led to many fascinating discoveries, which is always fun!

You're right about the tendency of an originally soggy root mass to remain soggy, even if you put put it in the middle of a mix that drains freely. BUT:

Most people think you shouldn't 'disturb' the roots of plants when you repot or pot up. When I get plants in cell packs or in, say 4" pots, unless the soil is literally falling off the roots when I remove the plant from the cell-pack or it's plastic pot, I unceremoniously rip the bottom half of the roots off & run my fingers up into the center of the roots & comb them outward with my fingers before I plant. Often too, I'll remove the low leaves from plants with stems & plant them very deep so a stronger root system develops all along the stem. If I'm planting in the ground, I sort of lay the plants diagonally in a trench instead of planting them vertically so the roots are better stimulated by the warmer soil at the surface.

I'm not a big fan of coir, especially in containers. It really doesn't bring anything to the table that peat doesn't offer except it's rewetability (some word, huh?), and it often brings salinity issues with it, as well as a very high K content. Also, it almost precludes your ability to use dolomite as a Ca/Mg source because of a pH that is already too high for it to be considered a favorable choice from that perspective. Most commercial ops that DO use coir or CHCs in their media limit their presence to around 10% or less.

2) I'm not really good with physics, honestly, but what you are describing is essentially a container related question. Since my seedlings will likely go to their 4x12' raised in a couple of weeks, I'm wondering if the same formulas work for that. If I fill an empty outside bed with bunch of gritty mix - does that stay relevant?

No - raised beds are essentially just gardens that are designed (usually) to help you manage drainage and/or water retention better. I don't think you'd be happy (almost certain you wouldn't unless growing plants that love arid conditions) with a soil as open (well-aerated) as the gritty mix in a raised bed. Most raised bed soils will perform very well with a 70-85% mineral content & the rest organic. We can talk more about your RB soils if you haven't filled them yet, or amending what you have. There are a lot of considerations to take into account & we haven't yet touched on them.

3) I have a new 4x4x2 beds in the ground for carrots. It's still not filled in. Planning to fill it up over the weekend and plant carrot seeds. Question: my book "Grow Vegetables" says: "Carrots grow best in an open, dry site in light soil that has plenty of rich, well-rotted compost or manure dug into it during previous fall.Importantly, the soil should be as free from stones as possible and not compacted - otherwise roots may fork or suffer from constricted growth." With this in mind - what the heck should I fill the bed with? maybe first foot of gritty mixture like the one you suggest in your original post and then the top foot with sand/soil/half-rotted mush from the composter with some chicken poop?

It's 2' deep? I think I would probably use about 75% screened topsoil or sand, and the rest fine pine or fir bark and/or finished compost - some reed/sedge peat is ok, too. It wouldn't hurt to mix in a little composted manure, and even a good fraction of horticultural (stay away from the stuff used for insulation - fire retardants & hydrophobic treatments so it doesn't absorb water) vermiculite would be a plus. Go light o anything you think will compost quickly because of N immobilization and the carrots won't like the heat it adds during the composting process.

Good luck - does that beget more questions? ;-)

Al

BTW... Your post caught me off-guard, when I first read it, I thought you were sifting to get rid of the "fines" ,not the other way around ;-)

You would have been much better off keeping the "bigger particles" and tossing the fines into your carrot bed ;-)

Al

That being said - how did you guess I'd have more questions?:)))

Speaking of roots, I only "rough around" with toms, eggplants and peps. They seem to get stronger from it. Are you suggesting that one can do this to not just night shades? Are there some plants you wouldn't do that to? (My guess here is that it would be a no-no with my mullein, lupins and borage).

Coir - I'm surprised to hear that you're not a fan. Wikipedia says it's superior alternative to peat because of sustainability issues of peat mining, plus choir has some kind of beneficial bacteria that protects the roots. It also seems less smelly/dusty than peat. I got a block of it yesterday as well as some perlite and put together the following mix:
roughly 35% fine black soil,
20% coir
20% perlite
20% composted wood chips that I sifted out of the commercial potting mixes over the past month
2.5% vermiculite
2% wood ash
0.5% worm castings.
Here's what happens on watering:

Water drains well but the area around the plant stem sinks in about 1". When I fill the hole back up and add a bit of water, the water just sits on top all mushy. I think I'm moving in the right direction, but not quite there yet.

RBs - when you say:"Most raised bed soils will perform very well with a 70-85% mineral content [...]", what do you mean by "mineral content" - any screened soil/sand or that plus specific minerals you add as plant food?
When it comes to my RBs, I have 15 4x12x1' wooden ones and 2 messy lasagnas of the same size for strawberries and potatoes. I've limed them about 1.5 months ago - but apparently not enough, because my pH test showed about 5.8-6.0. Now I worry I wont have a chance to lime them properly, since the plants will be in the ground in a couple of weeks. I do have some ash, though - I'm assuming it'll be safer in such a small time frame.
In terms of other things, K and P are fine, but N was horrendously low - those nightshades ate good last year :)). I wanted to add chicken manure, but it smelled so pungent, I was worried, it'd kill the roots, so I just added 4 cups of blood meal per bed and now the test shows normal N levels
btw, RBs are filled with crappy local soil (clay+sand +gravel+40%actual dirt) about 40-45% and the rest is last years' compost, peat moss, commercial topsoil and cow manure. All have metal window screen on the bottom to prevent gravel from washing up. Some beds look soggy, some have the look of the dessert - large cracks along the soil surface. I think it's a pretty safe bet to assume they are all compacted at this point, heh.

In regards to my carrot question - you actually suggest pretty rugged top layer. Hmmm...I was worried the seeds would have a hard time germinating in that texture but, the more I think about it, the more your advice seems sound.

Thank you so very very much once again.

Nadej

Pot style makes a big difference in what will grow well in it as well as the potting mix. I.E. if you have a plant that likes growing in somewhat "wet feet", plant it in a wide, shallow pot. The shorter the pot, the less total amount of water will drain out of it when irrigated, the opposite is true, a result of gravity and capillary action in the water column.

I wish I could give specific recipes but have been making mixes on the fly by feel for so many years I don't even pay any attention, sorry. In general, I use sifted peat and vermiculite usually for seeding, especially the smaller seeds and sifted peat with mostly perlite vs vermiculite for the cell packs. Pots get about 20% of the peat siftings + peat and perlite, depending on the plant it can also get some claey garden soil for added moisture retention.

I've tried many times(experiments) growing with coir and CHCs as replacements for peat and pine bark respectively with loose controls in place & have never had good results - even when coir was only about 15% of the mix, but YMMV. As far as the sustainability issue, I've done some researching on that, and here is a reply I often leave when that point is raised:

Sorry, but I'm not buying the non-renewable lament. In Canada alone, there are more than 270 million acres of harvestable peat bogs. If we make the conservative guess that the harvestable portions of these bogs are 10 feet deep, that means there are probably more than 900 billion cu. ft. available for harvest, just in Canada! That doesn't even take into consideration what's available in Europe, Asia, or places like New Zealand where they also mine peat, or those bogs that are NOT considered harvestable. Canada currently has mining/harvesting operations underway on approximately 40 thousand acres or about .014% (that reads 14 one thousandths of 1 percent)."

Check the math - it's accurate and conservative. It's more likely that the next ice age will be upon us and glaciers will have covered what's available before we even use a noticeable percentage.

Renewable/non-renewable = moot.

Water drains well but the area around the plant stem sinks in about 1". When I fill the hole back up and add a bit of water, the water just sits on top all mushy. I think I'm moving in the right direction, but not quite there yet.

I'm guessing this is your container soil? From what you said, I'm getting that your soil was 100% saturated - that it was so water retentive that it supported a perched water table at least equal to the depth of the soil. This means that the entire soil mass was probably completely filled with water. To be very direct, I really think you need to take a good look at basing your soil on a very large fraction of larger particulates, instead of the ones that are causing all the water retention. Most soils based on peat/coir/compost will support 3-6" of perched water after you water them a few times, and more as the soil ages. Perched water kills roots, and the more of it you have in the container after watering, the worse it is.

By mineral content in RBs, I meant something that remains stable - like topsoil, sand .... or it could be something like a Turface product - just so it doesn't break down and gas-out.

I wouldn't be too concerned about a pH of 5.8-6.0 in raised beds at all. I think you'll be just fine with that.

Be very careful with the blood meal at soil temperatures below 55* because of ammonium toxicity. I would withhold it until temps are comfortably above that benchmark.

Take care, and good luck!!! There's a container gardening forum too (that's where the link I left took you), where you can join in if you need more help with your containers. I really think you could do yourself a LOT of good and skip a whole growth cycle of heartache if you turned your container soil into your raised beds & started afresh with pine bark as the basis for your container soil. Remember, container soils are almost entirely about structure - you can do without the fine black soil, coir, vermiculite (also water-retentive), ash and w-castings.

Now that the talking is done, if you were here I'd offer you a blueberry or chocolate tea or a Cran-Grape juice (my fav), while I take in what you have to say.

AL

I didn't mean to open such a can of worms with the whole "peat mining" thing. Judging by your response, some people are hardcore against peat. I am not super OCD about the minute items like that. I just try to keep my stuff healthy and organic, to the degree that it is possible.

Just to make sure I understand, you are using unmilled sphagnum moss, correct? I'm asking because my coir is a lot more gritty than peat I've been using.

Thanks for the blood meal info, i will be mindful of that in the future (it ain't like they put this info on packaging, ya know? sheesh. So much to learn).
I'll definitely take your advice on redoing soil in some of my containers...rosemary is definitely not happy in the tall pot with "Nadej's finely sifted soil" after all the rain we had this week. And I will definitely check out the Container forum for more info.

thank you once again.

it has very good water retention, but holds no perched water. It retains its structure, remaining well-aerated for well beyond what a reasonable interval between repots would be, and plants thrive in it, which is attested to by the many using it at this and other forum sites. Rosemary loves it, btw - I have several as bonsai.

For short term plantings, like veggies and the many mixed display containers I have scattered throughout the garden, I use a soil of primarily fine pine bark, that you can see at 3,6 and 9 below. The soil itself (dry) is in the center of the picture.

AL

Other plants in the gritty mix:

..... lots more, but you get the picture. ;-)

Thanks, Jon!

AL

I'm so glad I've discovered this wonderful resource and your plants do look absolutely stunning!