Surely that cost doesn't include permit and engineer's stamp, which the 'garden center' should have told you may be required for a structure that high under that much pressure holding back that much weight, esp if it is above your house.

Throughout the 9000 years since agrarian societies began, hillsides have been terraced and cut-filled to grow crops, as water running straight downhill is suboptimal at best and after the first thunderstorm throughout history every time folks became unhappy. So.

Landscape timbers (4x4x8ft) hereabouts are ~US$1.00/ft so for two tiers at 3' each that is

1. ((35*9)*2) [runs] + ((12*2)*6) [posts] = (630) + (144) = $774

just for timbers, then you'll need to drain which is ~150 for gravel & pipe and fabric and concrete should be ~75 and hardware should be ~200 so that's roughly 774+150+75+200 = $1200 just in 2 minutes of thinking about it. You'll need a path between the two so that's ~75 for gravel and 30 for fabric so you're at 1300+ just for that material, and tax at 7.5% is another ~100 so you're at 1400+. Figure 10% contingency for delivery and drill bit breaking and augur and such, and that's a cheap wall that'll hopefully last 10 years if you take your time and do it right and there's a couple dry years in there and slow melting a couple years.

[/old landscaper]

Dan

We have a hillside garden with no retaining wall. I am not sure of the stats on the incline. We did have to do a fence for the deer.

Good luck with your garden project.

At one time we thought a retaining wall would be needed but this works just fine.{{gwi:291630}}

When I moved into my current house, one of the sinkholes in the back yard (about 30 feet deep and over 100 feet across) had eroded to the very edge of our street. The subdivision wanted to dump concrete garbage there which would have looked awful. One of the neighbors was having some trees removed and ground into chips, so I asked the tree people to blow those chips into the edge of my sinkhole and fill in the erosion gully. That was over 20 years ago and I've never had any more erosion there, plus it was free - the tree service has to pay to blow their chips into a landfill so they were happy to oblige me. You might try something like this - wherever you were thinking of putting bricks or ties, just put in chips. It sure worked for me, on a slope that was even greater than 45 degrees.

Use concrete blocks to build a series of terraces. Over time you can fill in behind the blocks with compost and soil. Be sure to run your planted rows across the hill and not up and down the hill. As you fill in the terraces, you can remove every other row of blocks and stack them on top if the row below as you widen each terrace. Don't try to do it all at one time. If you are young, you have lots of years to bring your dream garden to fruition.

Recycled concrete walls not over 18" high is a free way to make a series of terraces.

Dan

Well as far as the cost goes these would be my 3 suggestions.

1. Could do a dry stack wall of reclaimed/recycled concrete slabs. (i.e. broken up sidewalk) I've seen it done before and it tends to look much better than it sounds.

2. Concrete blocks covered in a thin layer of stucco or mortar could would made to look much better especially if you were to use a few "pretty bricks" to lay a cap stone along the wall's upper edge.

3. Try checking around sometimes you can find misc. lots of those retaining wall brick. Keep piling them up until you have enough, using them evenly spaced the difference in colors can often be made to look intentional and good. (we did that with our hardwood floors and it looks awesome.)