Cracks

The soil in our raised beds is drying with big wide cracks in it.....can you tell me what we've done wrong in our soil content? Thank you for any guidance...Deb

suggestions as to additives. We till it every year, have added peat moss as well as gypsum and compost....just don't understand as this is the 3rd year.....all of our tomatoes are growing but their leaves are twisted & curled....we've had that problem since the first year we grew them....we move them around so they don't grow in the same soil.....Thank you for any offer.....Deb

Deb, It sounds like a heavy clay soil. Is that right? What size are the raised beds? Here in Phoenix there are a number of companies where we can buy bulk garden soil.....by that I mean, we drive our old farm truck to the location and, using a front end loader, dump a large shovel-ful into the bed of the truck. One yard is about the size of a bathtub and is $28. This is how I have been amending the soil in our raised beds.

I also mulch with straw that has been run through our weed blower using the vacuum attachment. This cuts the straw to about 3" or 4" long. When I turn this in at the end of a season, it will decompose faster than if it was left in long sticks.

Hope this helps.

Thank you for responding.....yes, it is very much clay and it is very heavy....your suggestions are great and I hadn't thought of the straw staying in the bed.....we mulch all our beds with straw when we put them to bed before the snow, then I remove it in the spring & put it in the compost.....we're doing something wrong 'cause this is the third year....mainly what I'm worried about is we are putting raised gardens down in our orchard & don't want all this to go for naught......my start is to lasagne the area, let it lay over winter, spring we will til it all up & plant.....that will be the space for any "runner" kinda stuff: berries, squash, maybe some pumpkins.... we are taking our deck apart so will use the old spacers, etc for the new raised beds.....

What about a cover crop - like buckwheat maybe? Dunno. That's what I've got going right now. The buckwheat returns nitrogen to the soil.

The lazagna bed is a good start.

I think it's just going to take longer than you want/hope/expect......keep turning in compost and other organic matter. Maybe get into vermicomposting through the winter and turn that good stuff out to the bed in spring. Dunno. I'm nearly a neophyte myself.

1.
Add more compost. Then, even more. Keep adding more every year. If you don;t have a compost pile, many p[eople advocate dropping shredded leaves or other organic stuff onto the top of a bed and letting it compost in place (once called "sheet composting", now many people have a variation they call a "lasgana bed" with cradboard on top of the clay, and 12" plus of stuff on top of it. To me, that seems like growing IN a shallow compost heap, but many people have great success with it, and it cerrtainly takes much less effort than tilling.

2.
Mulch is good, espeically if it is fine enough that it dissoves into the soil after a few years. (In that case, it is like 'slow-release compost. Compost is what clay needs most)

I like pine bark mulch: either buy fairly fine stuff and just drop it on top of the soil, or screen the fine parts for turning under, and save the big chunks to lay on top of the soil as mulch.

Mulch slows down the rate of drying out, which may reduce cracking.

3.
Add LOTS of compost. As the secret of real estate is "location location location", the only way to make GOOD soil out of clay is compost, compost, and more compost.

Crushed rock (or very coarse sand), bark fines and gypsum are refinements, and may make it more friable or a little better-draining, but they won't cure clay until it has rather a lot of compost mixed well. I believe that, after you have almost enough compost, coarse crushed rock and bark fines do help ... but until you have enough compost mioxed in well, it won't be "soil", it will be "clay"


Heavy clay remains heavy clay until it is diluted a lot with fine compost. 50-50 clay and compost would not be excessive! Or 33%-33%-33% clay, compost and crushed rock ... but add more compost as soon as you can.

Also, compost is organic so it breaks down in the soil - faster in warm climates, and faster once the bed is adequately aerated. You have to add more compost every year. (I like to turn it under to speed up the rate of amending the deeper soil layers.)

Eventually, like after 3-5 years, when the soil has enough added organic matter to be "pretty good" even 12-18 inches down, you can probably just add compost on the top, and let worms and frost heaves mix it under for you.

I think of compost as the food that feeds soil life forms. As it dissolves, it releases "humic acids" that help dissolve needed nutrients out of mineral grains.

Corey

Thank you guys so much....very informative and helpful.....I am doing lasagne beds now down in our orchard so I can plant next spring.....we have lots of compost, nothing that can be composted gets thrown away here down to our napkins & paper towels + lint + all vegie scraps....it has huge nightcrawler type earthworms.....I need to get more peatmoss/coir in it and we get lots of llama poop too....that's why I'm so surprised it is cracking as it is.....we have been so careful about what has gone into these raised beds including gypsom every year....I think this year I will just clear everything out & start from the ground up.....sand, compost, peatmoss, straw + top soil is what I will mix up.....Thank you for answering me with such great guidance.....Deb

I wonder if tilling is causing this problem. I have heard time and again the soil structure is damaged from tilling and when rained on, will wash out the finer particles leaving the clay to turn into hardpan. Anyone have an opinion?

Rick has has it down path, tons of compost and it take years to establish a good garden or a weed free yard.

Belle

Have to agree with as much compost as you can stand.
I used to think i was pretty good but have found it really gets used up fast and it takes a LOT to get above water as it were.

Maybe (re the tilling) next spring when you plant squash etc, you could just shovel for the hill, don't till the rest, leave it covered from lasagne or mulched with something. I have had good results with squash or pumpkins planted right on the previous fall's leaf pile with some dirt on top, and the occasional dose of commercial fertilizer.

Mulch does help some. I like pine bark mulch (fine and coarse) because it "does it all", and lasts much longer than peat:

- protects the surface from wet / dry cycling

- protects the surface from raindrop impact

- arearates the soil with coarse structure when stirred in just a little

- softens the clay itself when mixed in intimately

- decomposes into organic matter over years

Corey

My vegetable garden was five years old this summer and the soil is as soft as one of those very expensive bed toppers you see advertised on TV!

The secret is compost. Keep adding as much of it as you can get your hands on. Mine is mostly fall leaves that have been left to break-down between the rows. Each spring/fall I take them up along with an inch or so of the under lying soil and add it to the beds. By this time the earth worms have broken down the leaves into worm castings.

Under the beds is hard, red Carolina clay which I leave alone.

I don't till my beds, just keep them weeded, and when I need to plant, I make a hole, fill it with water (if it hasn't rained recently), stir in organic fertilizer, add transplants, and pull the soil around the stem. If I'm sowing seeds, I don't make a hole, I dig a shallow trench.

I live in Clay Country but my soil is good. The secret is the TYPE of mulch. For years I used chipped wood from several trees that had been cut in the neighborjhood. The soil was replenished by the decomposing wood. I also supplement with compost from my pit. Almost NO commercial additives. Call a tree service - they'll be happy to dump a load on your property. Good Luck.