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Jun 15, 2016 8:34 PM CST
Name: Rick Corey
Everett WA 98204 (Zone 8a)
Sunset Zone 5. Koppen Csb. Eco 2f
Frugal Gardener Garden Procrastinator I helped beta test the first seed swap Plant and/or Seed Trader Seed Starter Region: Pacific Northwest
Photo Contest Winner: 2014 Avid Green Pages Reviewer Garden Ideas: Master Level Garden Sages I was one of the first 300 contributors to the plant database! I helped plan and beta test the plant database.
Hi Terry!

I think it comes down to "what's available locally" and "are you rich?"
But when in doubt about what soil needs, add lots and lots of compost. Especially for vegetables which tend to be heavier feeders than many flowers. (Compost adds many things, like water retention AND better drainage, C for soil organisms, and a LITTLE N, P and K for plants.)

If you can scrounge up the makings for compost, make huge amounts of compost. Put a compost heap right in each of your beds, and grow in them while you research what soil would be best. (Look up "lasagna gardening" if you think, like I used to, that "you can't grow directly in 100% compost!" Also, throw some sickly and lagging plants onto a compost heap, some day. If their roots can reach the compost, they will often recover miraculously and take over the heap. )

Whatever soil you have, that plus an equal volume of compost will probably give you pretty good soil.

However you get there, fertile soil needs "some of everything".

Some fine stuff for water retention.
Some coarse stuff for drainage and aeration and "soil structure")
Some (lots) of organic matter to feed the soil organisms you need to have healthy plants.
Some water. (But not too much or your roots will rot. The bed needs drainage, but sandy soil has excessive drainage.)
Some air! (This is crucial. Roots need to breath. Too much water or too many fines = no air = roots drown = dead plant.)

Some soluble minerals. (If you have only sand now, you might need to add measured amounts of chemical fertilizer for a few years, until all the compost you add makes the soil fertile in its own right. But not too much fertilizer! A little too much fertilizer is actually toxic, especially high-N fertilizers. Fertilize weakly, weekly, until your "dirt" has become "soil".

If money is no problem, look up "dirt yards" or "soil" or "mulch" or compost". $20-$30 per cubic yard, maybe, plus $$$ to truck it to your home and dump it. If you have your own truck, that becomes more affordable.

I go for something like "three-way-mix": "topsoil", "compost" and bark or grit. But you are at their mercy when it comes to quality unless you can push your hands into their piles - and hope they take from the part of the pile that customers can see. I bought three cubic yards of soil once. First I checked carefully that the "topsoil" was light and loose and freely-draining. What they brought to my house was typical heavy clay. Thumbs down Even so, it was better than my VERY heavy clay!

I live where there is only clay soil, clay, and heavy clay. So if I pay for "store-bought" soil, I want something that improves drainage and adds organic matter: compost, medium/coarse ground bark, compost, grit, compost, very coarse sand and more compost.

If you have sandy soil yourself, you need to add organic matter and stuff that holds water: compost, I-don't-know-, and more compost. Fine bark holds water and lasts MUCH longer than peat.

But compost is consumed by the soil organisms you are encouraging. You have to add more every year. It would be nice to add 1-2 inches twice a year! But any helps. You can also "top-dress" or mulch your soil with the makings for compost, then call them "mulch". After they decompose and melt into the soil, you were "sheet composting" the whole time.

Some people mulch with a SIX INCH layer of leaves every fall. Depending on the type of leaves, it turns to compiost in 6-18 months (maybe 24 months for oak leaves).

Does anyone actually SELL clay? If so, add no more than 10% clay to your base sand, and see what that does. Go easy, because some say that any soil that has more than 20% clay, acts just like clay. My "soil triangle" would put that number around 35% ... but I would have to move to find out for myself.

When in doubt, just add a LOT of compost to your existing soil and make sure there is some drainage out of the bed. (Don't have plastic walls and plastic floor: that's a bathtub and roots won;t grow in a mud wallow.)

Cultivate that for a few years and give soil organisms and plant roots and ongoing compost additions a chance to improve your soil.

THEN consider spending $$$ on specific soil amendments when you know what you need, and what is just "dirt yard hype".

Oh, yes. Biosolids. The Cadillac of compost.

Depending on how much you believe local governments (hah!) or the engineers who run sewage treatment plants, "bio-solids" are just composted human manure, and as valuable as composted farm-animal manure. The engineers rave about all the tests they do, and HAVE TO pass - salinity, E. coli and other organisms, heavy metals, runoff chemicals - Class A biosolids are healthy like certified-pure rose petals if you believe the engineers.

In the past, there have been unregulated biosolids that were as saline as some farm manure, or had detectable heavy metals. Maybe Class B had detectable bacteria, but there are laws about where you can spread Class B (farms, I think, just not on lettuce and sell it shortly thereafter). Some people are still afraid of the problems that existed in the past.

If it were only the politicians telling me "we test for that!", I would not believe them for one millisecond. But the engineers say the same thing, and I trust them. I talked to a local "Schiessmeister" and he was really proud of his biosolids! But they give them away to Cedar Grove, who mix them with tons of sawdust and sell the result for a lot of money.

If you have a truck and a local sewage treatment plant, you can have the biggest compost heap in the valley for free ... but they do NOT test it to be odorless!

Everyone has a local sewage treatment plant, because everyone defecates. Kind of like North Carolina: where do transgender people go to the bathroom? The same places they've been going for generations. They haven't been "holding it in" all their lives!

Since biosolids are always going to be produced locally, and then spread on farms or given away to Cedar Grove (who charges for them), we might as well eliminate the middleman (so to speak) and use them directly.

Opinions vary, and those who suspect biosolids for various reasons may be righter than I am.
But if I had a truck, my neighbors would be complaining about the smell!

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