CMU blocks (concrete masonry units) are about as inexpensive as you can get. About $1.75 each at Home Depot, etc. But they are also some of the least attractive materials you can use for a raised bed......yet perfectly functional :-) Dimensions are standardized at 8"x8"x16" so you can plot out exactly how many you need to determine cost.

Any material made of concrete (CMU's, wall blocks, concrete pavers or cobbles, etc.) will leach lime but not to the extent where it is considered toxic or that will prohibit plant growth.

Lol yes CMU blocks sure are unattractive! So I know I will have to hire a company— I can’t do the physical work myself.

I just want to have a direction / vision to share with whatever companies I bring by for estimates.

I am guessing the labor will be as much as, if not more than the materials. Also need the old rocks hauled away.

Is the yard always that shady? Vegetables will need at least 6 - 8 hours of direct sunlight. I've used HD retaining wall blocks to make a planter, and I have metal raised beds for vegetables that work quite well. They are open at the bottom.

Top soil can be anything, so isn't the best for a vegetable garden.

They prefer a cement, brick, paver, or cinder block material however I read on some web pages cinderblocks might be toxic— is that true?

Pardon the background info, but you should come up to speed:

In the genre of materials your parents prefer, you have a choice of CMU, brick, or stone. AFAIK, you cannot find "cinder blocks" anymore - those ceased being made in the 1950s or so. The cinders are what is considered toxic (you may find lightweight blocks with fly ash or such, but for outdoor use any "cinder" material would be too soft for weathering). "Cinder block" has unfortunately stuck around as a word mistakenly describing modern CMUs. "Cement" is the glue that holds a CMU together.

- CMU (as mentioned by others) is made from concrete and is the cheapest, they are a standard size but you can find different decorative faces and colors. You can see your fence has smooth face and detailing with a decorative face. These would need to be mortared together and probably have to have a concrete footing for success.

- "Retaining wall blocks" is what all your inspiration pics show. It is still a CMU, however, for a retaining wall they can be installed easily with a gravel footing and some adhesive (either not necessarily required though). They also come in different sizes, decorative faces, colors, and many interlock with each other. In your case, a planter bed would be a "garden wall" only 2 or 3 courses high. These blocks can leach dirt through the joints, so that should be addressed.

- A "paver" is also just a CMU, but a small size and made for horizontal surfaces. You have them for the paito.

- "Brick" is made of kiln-fired clay, smaller in size and need to be mortared together.

- "Natural stone" would need mortared together for a thin wall application, but for drywall (cut stone around 6"-8" high) they can be stacked loose like retaining wall blocks.

For this situation, retaining walls blocks are on point. You should choose something that doesn't compete with what's there - the fence, the paver patio, the concrete slabs - there's a lot goin on. They can be moved or removed easily in the future. The bed itself should have a liner on the walls, and maybe address drip irrigation (even just as an attachment to their garden hose during the day). Soil will have to be amended for your use.

I really appreciate all the feedback!

Igteacher - your retaining wall planter looks great, I like that it is a rounded shape! From the looks of it, it is a nice chill spot for the furry friends. Your metal planter seems to be doing well too with all that green lush vegetation.

The yard is not that shady alll the time. The photos were taken early evening and there are times of the day when there is direct hot sun for several hours (less so against the walls due to the shadow of the trees).

My mom wouldn’t go for metal, but last night I ventured onto the HD and Lowe’s site and saw some decent examples of retaining wall material. We would be requesting the landscape company to skim off some of the old soil and rocks and put in top soil.

Should we have them put in anything else or do the amendments ourselves? I’m not very strong and have a small car and no other help, but can add a few bags of whatever amendments are recommended at a time.

ital mover - I wish I could change my mom’s mind too! The whole project then would be done for thousands of dollars less! My mom isn’t so much for organic gardening but I think I jogged her memory of how fun gardening can be by watching lots of gardening YouTube videos when she visits me. Such a great hobby! I myself have only a tiny patio in my condo.

3onthetree- thank you so much! I very much appreciate the “background” information!

I also feel better knowing that cinder ash isn’t really an issue to be concerned about.

You’re on point with the types of material that can be used. It all makes sense now looking at the Home Depot website and how they’ve categorized into such things as retaining wall blocks, garden wall blocks, pavers, stepping stones, etc.

You also made another good point about picking a material that doesn’t compete so much with all we already have going on there. I’ll try to get my mom to settle for something simpler that can blend in coloring wise to the existing pavers.

See the picture of our neighbor’s front yard planter my mom wants to emulate— I won’t let her though!

For retaining wall material, how do you recommend we deal with the soil leaching dirt thru the joints? Is a liner sufficient? What soil amendments do we need to do to the top soil? Manure? Sand?

Thank you again! You clearly laid out the different options for material and the basics of how the install should work. Now I know to go over that with whoever we end up hiring.

neighbor‘s frontyard garden wall:

My rounded planter made of retaining wall blocks hasn't seemed to leach soil and it's been there for several years. I put some landscape fabric around the sides. I'm over 65 and did the installation myself.

Retaining wall blocks do not leach soil from a retained pile of dirt either!! It is pretty much a non-issue.

lgteacher -- did you do the install of the retaining walls yourself? or just the landscape fabric?

Retaining wall blocks do not leach soil from a retained pile of dirt either!! It is pretty much a non-issue.

As always, YMMV, but maybe you are referring to retaining walls with a gravel plane and fabric behind. Maybe used tons of adhesive like a sealant. Maybe gravel-filled hollow core blocks. Don't know, but if you've ever built some garden wall products (where it's just dirt against the backside), it doesn't hurt to put fabric or polyethylene against the wall. It's not leaching like milk poured from a carton, the water coming through joints is mucky and stains the blocks requiring a periodic washdown.

pressure wash for the staining? I know my parents would never get to doing that so we would need to make sure we cover up the walls with landscape fabric as much as possible.