Here is one more photo from above.

Bumping this one to see if it got lost over the weekend. I hope to start this project soon and am worried by the silence if this is just totally the wrong thing to do and there wasn't room for constructive comments :>) I promise I have broad shoulders.

I think it's a really good idea! A part-time green house kind of thing, right?
I would enlarge the wall, I think your concerns are valid. Maybe use the wall to the left as one side and extend the other three walls out the same distance. If all goes well your tree will almost fill this area, and you will still have some room to move around it for maintenence, etc.

It would be a lot easier to just buy four prefabbed concrete post hole foundations with a 4 by 4 bracket you could bury without mortar to hold the scaffolding support base for the temporary winter frost blanket. Use short four by four fir lengths with holes drilled thru them using 3/8' 5" stainless lag bolts with thumb screws so it would be easy to remove them when it isn't cold. You could attach the pvc pipe with brackets to the 4 X 4 lengths.

If those air conditioner units are heat pumps they will kill your tree if you use them to heat your house on a cold night. If they are just air conditioners you will be safe. Otherwise I would go with Joncha's idea. Much easier.

Steve

Thanks for the input. Yes, it will be an easy up/easy down greenhouse. We sometimes go from sub-freezing at night to hot the next day so I have to pull tarps off before I leave for work to keep plants from getting too hot during the day. In addition, I need the low wall to hold the sand I mounded up for the tree. Might be hard to see in the photo but the soil at the tree is about 14" higher than surrounding soil. Sizing for the dimensions is the hard part since I have no idea if this tree will reach published proportions in my area.

I'll try to post an update later.

I guess i am not understanding why you want to build a raised bed in that location. Is it too much drainage or not enough.

Brick retainer walls are at best semi permanent. You could just use wood to create a large box which is easier to remove if need be.

Did not apply to this situation. Best of luck to you.

Steve

This post was edited by poncirusguy on Wed, Jun 18, 14 at 14:56

My purpose for the retaining wall is two-fold. Primarily to keep our 60inches of annual rain from washing dirt off the mound I planted the tree on and into the low area around the tree that needs to stay low enough to drain water from around my house. I want the low wall to be visually appealing so I plan to match it with the rock wall (part of an outdoor shower). The bonus for the sturdy wall is that I can use it to help support a freeze cover during cold winter nights. My main purpose for posting was to get input from folks with mature Dancys to see how big they get. I'm guessing mine won't get as big as some since my winters will be a little rough on my tree. I'm in Zone II, it's recommended for Zone I.

I finished the rock work for the retaining wall this past weekend so here is an update. I ultimately opted to make it 10' X 10' and used the existing structure as one of the walls as Barb suggested. I lack a little dirt work around the outside but it's essentially finished. I used about 30 bags of sacrete to form an underground footer for the wall. To allow for drainage, I didn't grout between the ledge stones on the close end. I think I'll bury PVC posts inside the wall at the four corners to provide a foundation for a wintertime cover framework. It will have to be easy-on/easy-off since our winters are usually mixed with sunny days when the plants have to be uncovered.

Fantastic job. Great looking tree. I hope your tree does very well.

Steve

LOL! Yes, I hope so too. I have less invested in the tree than in the surround. Lesseee, about $25 for the tree, $150 for concrete, $30 for mortar, $100 for stone, and $60 for soil ammendments. All that and the butterfly worms, leaf miners, and whiteflies are all trying to gang up on my poor tree. It is putting on its third growth flush and has three tangerines so it's looking pretty good thus far.