IME, your problem isn't poor soil, but a lack of heat during a short growing season. Do your neighbors succeed in growing tomatoes? Ask them what varieties, and if they have any special tricks. Here, everything revolves around extremely short season types, and soil warming tricks. Raised beds are popular not because they contain special soil, but because they warm up early.

Neighbor across the street got plenty, but I'm pretty sure he used a ton of chemicals (he also has a lawn like a golf course). Basically, everything I put in these beds didn't do squat (there was also kale, basil, etc). My kale and basil in other containers did pretty well.

But, I do agree with you. soil is probably not the only issue. Last year was a generally poor growing season for us.

"None reached more than about 2 feet. Frustrated, I looked to the soil, and realized that what we had was really silty bordering on clay. When I pulled the tomatoes in the fall, it was clear that they all had really stunted roots. "

What was your watering like? Roots will follow water, and if the bed was getting frequent but small amounts of water the roots would stay shallow.

Tomatoes like deep watering.

Deep water about once a week. It's not just that the roots stayed shallow, they didn't grow at all from transplant.

It sounds like you need some fertilization.

It sounds like you need some fertilization.

Thanks. That's a thought too.

I was taught that tomatoes will use (here in Texas) 2 gallons of water per plant per day. They really like moisture. Maybe you get rain in the summer though.

Hmmm pkponder, I was told to let the maters dry out between watering here in dry Ca! I usually only do a deep watering one time per week.
Also, before starting new beds, do some research (I didn't). After looking into things, I dug/forked down as deep as possible (during the 2 week window of digging between muck and concrete!) added aged manure (freecycle) and compost (landfill), watered it in, made the boxes with hardware cloth for gophers, added more of the soil from the landfill (organic!)
I've been gardening in theses boxes for almost 15 years! Adding home made compost each year and getting a truckload of the landfill compost every year or so (a big $12-15!) Nancy

You've been doing a lot of great things to improve the soil, but much of it will start having a significant impact after several more years. In the meantime, nitrogen is being locked up in the soil by things like the peat moss and leaves. It's good stuff, but you're going to need some extra nitrogen to grow crops until all you need to add is yearly, well-aged compost.

You need a good reliable soil test so you know what the pH of the soil is and what nutrients are available or might be needed. Your Iowa State University does soil testing. In addition you may want to use these simple soil tests for a more in depth look at the soil you have.
1) Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.
2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains’ too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.
3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.
4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell, to a point. Too much organic matter can be bad as well.
5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

Here is a link that might be useful: ISU soil testing

If you've been gardening and adding amendments for that many years, I'd get a soil test too.

How is the light situation - are there trees shading things? How about roots from distant trees? They can go 50 ft at least. I had these problems with an established garden (15+ years) that was not producing to the level that soil test results suggested. Moved beds into the sun away from tree roots and things really took off.

Just to clarify, the only amendments were made at the end of last growing season, so I haven't grown anything but a cover crop in the soil.

The light is good. Southern exposure, only one big tree that briefly casts a shadow during the day, and the nearest house is pretty far away.

>You need a good reliable soil test so you know what the pH of the soil is and what nutrients are available or might be neededThere it is.

You shouldn't do a lot of amending or fertilizing without having some kind of baseline first. You can poison the soil by applying minerals you already have enough of - many products contain a lot of phosphorus for instance, which effectively doesn't leach out of the soil. So if you produce a phosphorus toxicity through over-application of phosphorus you have to remove and replace the soil to correct it.

Thanks. I'll definitely get it tested, though I was under the impression that compost, vermicompost, and green manure would pretty much never hurt

I think the so called top soil was not very good. Then you did not really dig in and remove the dead grass parts, its like the dead grass can create a problem if it won't decay. I would not use top soil, who knows what that is, and use compost and dig it in as far as the root zone of what you want to plant. You may have to remove some of the bad soil, add lots of compost, I mean a lot, and also give it some time to take effect. Maybe start in just one small test area if that is too much work to do the whole thing and see if you get an improvement? Just adding tiny bits of vermicompost won't really help very much, it will just be lost in the overall soil.

Thanks tropical_thought.

Without a soil analysis, I guess I'm just speculating here, but the soil did come from a farm, and in general, Iowa topsoil is pretty rich. The big issue here (at least pending analysis) struck me as the texture being too fine.

One dimension I left out before is depth. The soil on top of the dead grass is close to a foot deep.

I agree with you on the vermicompost being a small addition at the moment. I'm hoping that It can be used effectively by targeting specific plants, but I agree, mixing it in to the beds wont' do much overall

Organic matter compost, vermicompost, vegetative waste, manures) can help all soils to a point. Without adequate levels of organic matter in the soil the Soil Food Web cannot function well and major parts of how plants evolved would be missing. Too much organic matter in soils can be detrimental as well because then the soil might hold too much water which causes problems for the Soil Food Web as well, excluding the air they need to function.
Rather than attempting to "target" specific plants, unless they are growing in containers, work on getting the soil into balance.

Not sure how I got the idea you had been amending for a long time, sorry bout that. I would not be too concerned about over-fertilizing with compost, at least not at this stage of the game. I used a lot of compost on my clay and after about 20 years it got very high in P and K, but it actually grows a great garden in spite of that. I'm just cutting back on adding high levels of those - i.e. no fert. with P or K and minimal compost additions.

It does sound like texture is something to concentrate on. That peat probably was a great idea, although locally sourced compost and leaf mould will accomplish the same things over time.

You might want to try different soil just an experiment. Residual farm chemicals such as glyphosate or picloram might be at work here.

Of the soil types, clay, sand, and silt, clay is the best. If you can get something that's a mixture of clay, silt and sand, that's supposed to be better, but I would not attempt to create this mixture if you have clay soil.

What is your native soil, the stuff you buried? A soil test would be good, but just to find out what the P, K, and pH are. Forget the Nitrogen, it's transitory.

Yes, I do find spot composing can sort of help one plant at a time. You want the soil to have water go right in it. Even if you only dig down a five inches and put compost there, it helps because otherwise the water could just sits or worse yet runs off before it reaches the roots. The compost acts like a big sponge and sucks up all the water and makes the water stay right where it should be which is near the plant roots.
If it seems too much work, just go it in one small area and you will like the result I hope enough to continue one small area at a time. Like maybe do one small part per month and with in a few years it will all be done, but of then you have keep topping off the compost, but the first time is the hardest. The ground is the hardest to dig in the beginning and it needs the most compost the first time. If the ground is very hard, apply the compost and water then wait a day and then it will be easier to dig.

Also its best to make your own compost in bin but you can also buy compost. Peat is not that great, it helps a bit, someone was mentioning peat. It would be great if you could find some company to bring you a truck load of organic compost with no sand, silt, clay, since you got a lot of that already. I found a company that called it vegetable growing mix. Peat is too expensive anyway, when you need a lot, I like bagged wood, mixed with free starbucks coffee grounds which you can get for free. That mixture can be used as a matrix to add your own kitchen scraps or you can dig it right in now. The coffee has lots of nitrogen so there is no problem with the wood causing nitrogen tie up. If you want to do some moderate feeding, I say good ahead. I use less then they say to use, because less is more and they want to use a lot and buy more from them. I use maybe half of what they say in feeding.

Some people have known for years that the best garden soil is loam, a mixture of ingredients that is roughly 45 percent sand, 25 percent silt, 25 percent clay and 5 percent organic matter. But loam is not very readily available and most of us must to work with what we have, I have also found people that think "topsoil" and loam are the same thing and they are not. "Topsoil" is, quite simply, the top 4 to 6 inches of soil from someplace. "Topsoil" may be something worthwhile or it may be garbage.
It is best, mostly to make the mineral portion of the soil type you have, be it sand or clay, into a good healthy soil by adding adequate quantities of organic matter to it.