Garden Soil or Compost?

[ArcherB]

I've dug a trench for new bed. Our "soil" is about four inches of red clay on top of hard, sticky, black clay. This is why I dug it all out. I'm tired of fighting with it and do not want to compromise in this new bed. I plan on growing various greens in this bed, such as collards, kale and spinach. I also plan on using whatever is left over for my tomatoes in the other beds as well as containers. In searching for bulk soils to fill the trench, I have some questions. First, my trench description:

It runs the width of my yard, about two feed down and two feet wide with brick edging that will sticks up about a foot above the surface.

I don't know if that matters, but question is, do I use garden soil or pure compost? The price is the same. Here are the descriptions of each:

Flower And Garden Soil

Blended from organic matter, fungal compost, decomposed granite, our Bed Mix and humates, this soil is rich in iron and sulfur. It comes ready to use. So spread it on your lawn and fill up your flower beds with vibrant, colorful life.

and...

Triple Power Compost

The highest quality compost in the land. Blended from manure, Texas hardwoods and organic matter. Rich in iron and sulfur with a pH of 6, perfect for Central Texas. Great for increasing the vibrance of flower and vegetable beds. Best for lawns when blended with existing soil or our Turf Mix/Topdressing.
...
Vegetable and Flower Gardens – Spread 1″ of Triple Power Compost (approximately 8 bags per 100 sq. ft.) thoroughly work into the top 4 to 6″ of soil prior to planting.

[Worth1]

Use a 50/50 mix of compost and sandy loam with some peatmoss mixed in.

It works and if you can, make the trench 3 feet wide.
Suze who posts here uses this and I dare anyone to say her tomatoes dont grow.

I have also used compost mixed with sandy loam that already existed here at my house.
Straight compost is not the way to go for sure.

You would also be better off to raise the beds a little even 6 inches will help.
If the soil is as you say you will need the seepage/drainage.

I see you have brick edging that sticks up a foot I suppose the dirt will fill this up.

I'm guessing that red clay stuff is from haul in for your yard when the house was being built.
Builders will use any cheap garbage they can find.

That black clay you speak of is a black gumbo, I have planted right in it in Central Austin (Hyde Park 51st Avenue G) with great results.
The red clay is the culprit for the poor growth.
The garden soil would be better for sure.




Worth

[Medbury Gardens]

Well i think if the price is the same you should use garden soil to full the beds and add some compost at the end.
The thing is,fulling only with compost the level will drop as it further decomposes so you'll end up having to buy more,you wont get that with soil.

[ArcherB]

Originally Posted by Worth1

It works and if you can, make the trench 3 feet wide.

It's actually a new extension to an existing bed. I dug the trench next to the bricks of another bed and simply moved the bricks to the other side of the trench. The entire bed will be about six feet with various shrubs along the fence on the back side. Any roots that go beyond the two feet of trench walls will find itself in the gumbo and red clay that was dug out. If they want it, they are welcome to it.

Originally Posted by Worth1

That black clay you speak of is a black gumbo, I have planted right in it in Central Austin (Hyde Park 51st Avenue G) with great results.

You are a bad man! I weigh in at 175 lbs. I've stood on my shovel and jumped up and down like it was a pogo stick and not penetrated that stuff. After a rain, it takes a couple of days for it to absorb water and even longer to dry back out again. I'm told not to work the stuff wet, can't break into it dry. When it is wet and I work it anyway, it's penetrable, but you only get one shot as the stuff sticks to the shovel must be scraped off with large pieces of mulch because it stays stuck to whatever you remove it with. DON'T use your shoes! I've heard that mixing sand it will make it into concrete, but I feel concrete would be an improvement. At least concrete will break up with enough pressure.

So, do you fertilize or does black gumbo have nutritional value?

Alright, here's what I'll do. Since money is tight and my handy yardage calculator tells me I'm gonna need 4+ yards of this stuff, I think I'm gonna fill in with what I already have and whatever I can grab. I'm gonna fill the trench up about half way with my unfinished compost, cardboard, newpapers, coffee grounds... all that good stuff plus some "Zilker Park Christmas Tree Mulch" that I'm gonna pick up in a couple of weeks. I don't think anything I'll plant this year will reach this far down anyway. I'll put about a foot of garden SOIL and then top it all off with my finished home made compost (probably a few inches worth). Yes, I realize that as the bottom stuff breaks down, the level will drop, but that's OK as it will allow me to add fresh stuff next year.

Either way, I spent way too much time digging all that stuff out. I'm not putting it back. I'll have a sunken bed before I do that!


Thanx to both you guys for the advice.

[feldon30]

One thing to realize:

If you have a yard full of sticky heavy poorly draining clay, dig some of it out, and add good soil, you're just creating a "well" effect. Whenever it rains, the part you dug out will fill up with water and stay waterlogged for hours/days, killing everything you plant in it.

Raised Beds allow you to rise above the problem all while slowly improving the underlying and surrounding soil.

[dice]

HarleySilo had poorly draining red clay in Georgia. He dug a trench
like you describe and filled it with mushroom compost plus other stuff,
IIRC. He used roll-roofing for mulch that extended out beyond the sides
of the bed to keep it from becoming a bathtub in the rain.

If you have raised beds, the rain will drain down until it hits the clay, then
seep sideways out around the edges of the raised beds.

[ArcherB]

Thanx guys. I hope to have enough "stuff" to fill the trench above the original ground level. If not, I may just have to keep an eye on it and bail as needed.