Building a raised garden bed using concrete blocks on a slope

[DirtMechanic]

The more I have observed the area that gets the most sunlight has the most slope. It also has the least amount of grass, mainly weed although there is a small amount of grass. So all in all I will probably layout the area with small posts and string and spray the area with round up

I will wait a couple of weeks and use wood. Knowing that it will not last a long time. especially the parts that are below the soil.

I have not decided on the size of the lumber. No sense in spending a lot since it will have to be replaced.

put a bunch of borax laundry powder down the holes.

 

[River]

put a bunch of borax laundry powder down the holes.

What holes?

 

[DirtMechanic]

What holes?

I assume you would be digging some kind of stop on the the bottom side. Are you just going to make wood boxes that lay upon the ground?

 

[River]

I assume you would be digging some kind of stop on the the bottom side. Are you just going to make wood boxes that lay upon the ground?

I am sorting that out. I have watched a number of you tube videos and some just lay them on top. Then drive a post down and secure it on each corner. Others use A pick ax and scrape out the area the frame will lay on and After that build up the lower side with pavers or dirt to get it level.

I would like yalls opinions. If it was on Level ground it would be a piece of cake

I checked out the book at our library by Simon akeroyd raised bed gardening but nothing about building it on a slope

 

[Mr_Yan]

I have put in retaining walls with the castle block style interlocking concrete blocks. Are these actually what you meant or were you thinking mortared together 16" x 8" x 8" dimensional cinder blocks? For some reason my mind went to cinder blocks when you said concrete blocks.

Castle blocks sit on a packed base of crushed stone to level them out as you set them. They're also designed to lock together and work in curves. With these a curve adds strength but a long straight run will be weak and want to lean over to the non-dirt side over time.

I have also put in retaining walls with pressure treated landscaping timbers. The PT differs from standard lumber by only offering a few more years. Construction is the same.

(My opinion) If you're putting in a wooden wall longer than 8 feet or higher than 2 feet you should have fence posts set into the ground on the non-dirt side of the wall then the wall material stacked between the post and the dirt. This way the full strength of the post is holding the wall not just the fastener.

As you don't want modern pressure treated wood there are old school DIY preservatives worth looking into if you go with wood. One I have heard of but not researched is boiled linseed oil mixed with charcoal dust - linseed oil is made from flax seed and charcoal is just burnt wood.

Think about the life time of each material. The biggest cost of this project will be the labor putting it in, not the materials. Trust me it sucks to spend hours rebuilding something in 3 years because I tried to save $100 the first time.

Either material works but both have the limitation that a long straight line will be weak and want to cave over. There were a lot of retaining walls leaning over in the neighborhood I used to live in where everyone had a flatish lawn but the street was on a hill. Then within 10 years everyone spent a lot of money to have someone else replace the walls - most of those houses are 100 years old now.

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For raised beds I prefer setting the garden bed wall a few inches into the soil. I think it gives a cleaner looking line and I don't have soil wash out of voids where the ground dipped a little. Plus it plays into my engineer OCD mind to have the bed set level and square to the other beds but that is a different topic.

 

[River]

I don’t plan on building any higher than 12 inches.
Here are pics to give you an idea of the slope. Our house runs north to south. The pics show the north side of the house. Not sure if you can tell that it is sloped to the west and a bit to the north. In fact, the north stakes measures 9 inches and the other side 8 inches. You can see I am running the 8 ft length from south to north and the 4 ft East to west

 

[MintBasil]

Looking for the solution to same problem u mentioned. If u made the beds would u mind sharing sone pics and details. Did u made the tutorial by any chance. This thread us from last tr hopefully u will see this. Thanks