CactiGuide.com

Almost 28 years ago we built a detached garage and I included an extra foundation on the south side for a mini greenhouse/cold frame. It has been very lonely all these years just collecting water when it rains. But, now that I've retired I got inspired to start the job.

I have a friend that has worked in a few of the local commercial greenhouse's as maintenance/construction for more than 20 years. He is helping me with this project. Here is the drawing I sent over to him back in November 2021. This will not be the final design. Brian has some tweaks he wants to put in. Here's an overall view of the pit and garage to help you understand the drawing:
This is what it looked like at the beginning of August this year. You will notice the joint between the garage and the side wall has moved. It is really worse than this: the front wall has been pushed inward by frost heaving about an inch down between the first and second block. It is still firmly attached to the footing, but it came apart along the joint between the first two layers of block. I had a mason look at it and he advised me to ignore it because to fix it the entire pit would have to have new block laid. I asked about pushing it back and he said my structure will be so light that I won't have to worry about it moving. Especially since I've filled the pit with stone and fill dirt well packed in.
Here's two of the heaved wall:
And here is the first layer of rocks and dirt being added:
This is what the pit looks like after I've added all of the dirt and rocks, and before I add gravel and cement for the top layer. I should say that I soaked the entire pit with the hose to saturate the dirt and turn it into mud. This let the air get out and it packed in the dirt between the rocks. I stomped the rocks down with my boots while it was very much like pudding. I kept adding smaller stones and pushing them in until I had a firm surface to walk on.
I just checked the long range forecast and it looks like we are going to have light rain all the way through into Wednesday, so it looks like construction will be on hold for a bit.

To be continued.

This looks interesting. Looking forward to seeing pics of the progress

Many greenhouses have very serious defect: they are (become soon) very small...

I know it is too small already, but I built the foundation decades ago. It really was to be a place for winter storage of dormant plants. Now I have Carnivorous plants that will need storing. We'll see.

So, with time pressing in and not really thinking it will be possible to get this done before it is needed this season, I am going to plan B.

I will re-think the design and maybe make it bigger! I'll have to go out of the footings prepared. Maybe sink some Sono Tubes for two more footings-but that might run me afoul of zoning ordinances.

I will see if I can store my plants at my friends greenhouse this winter. I have to get out of there in early spring though, so it may be a problem for me. But, it is what I've done before when he was working for others as their Grower.

Well, its been almost a year. Since last year I filled the pit with clay soil and rocks to about a foot below the top and then put it a 3" layer of 3/4" gravel. See photos above for the clay fill. I was going to put cement on top of the gravel but didn't get there. Now I don't think I will use this place at all except for outdoor storage of my winter hardy carnivorous plants. It still floods and is too small as Anntisepp pointed out.

Now I'm thinking of just making a large table that I can cover over to prevent untimely rain from wetting my plants. I can do this in a much sunnier spot and I can also make it big enough for my Carnivorous plants. All plants will get more sun and I can shade those that need it. Any ideas construction wise?