All my Zone 5/6 clues about what good gardening soil looks like are out the window here in Chacala. At my first place in Chacala the soil looked like hard packed red clay to me. And Aurora, my landlady was growing very nice bouganvilleas and hibiscus and other plants right in it. She was trying to grow roses in the dirt, but ended up using pots with river dirt.
Aurora and I did some landscaping in front of her rental units, a small flower bed. We built the walls around it with miscellaneous rocks and bricks and cement blocks, and then headed for a local river bed for sandy-looking soil. The plants grew okay in the dirt, but not vigorously, and I wasn't sure what to do. The soil compacted easily, and water tended to run-off rather that soak in.
In my previous gardening life I would have just added organic matter. At the farm I would have had compost and hay/straw, chicken bedding, cow bedding, all kinds of stuff. In town, I would have gone to the local garden supply and gotten a truckload of nice compost, or topsoil, or whatever I wanted. It's different here, and I think the main problems are not knowing enough garden Spanish, and not understanding the thinking about soil here.
I spend alot of time around in Chacala looking at other people's gardens and flower pots. I have never been able to easily stick my finger into the soil the plants are in. It is always hard, like clay. I am assuming it's lack of organic material. Most people in town rake around their houses daily (mostly raking leaves from fruit and other trees), leaving the ground hard and bare. They burn the leaves they rake up.
Every house has some effort at growing flowers, and there are fruit nears neat most houses.
Most people grow their plants in pots, using sandy soil they have gotten from some river bed.
I have done that, and have also been buying gunny sacks full of "topsoil" at the two plant nurseries in the second town over from here (near La Penita). It's potluck what kind of dirt will be in those sacks. The first few times I bought sacks of dirt it WAS nice rich topsoil, and the plants did well in pots filled with it. But sometimes its almost straight sand and other times it looks good until you get it wet and then it turns to what appears to be straight clay.
I always ask people with nice plants where they got their dirt, and the answers are not clear. I think only a few people (my old landladies mainly) are willing to share their dirt sources. On the other hand, maybe they don't understand what I am asking or I don't understand their answers. My Spanish is improving, but it's still difficult when the person speaks quickly.
A couple of weeks ago I thought my prayers for good soil were answered. The landscapers for the big gated community near where I am living trucked in about 30 large dump truck loads of what looked like good topsoil right in front of the mango orchard next to the house. They said they were making a dirt storage pile for plantings around the newer houses in the development.
I say "looked like" because, after carrying, with permission, 12 bucket fulls of dirt up to the house, I realized it was very claylike, and I guess had no organic matter. I put some in planting pots and watered it. The next day it looked like I had made round bricks. I turned the pots over and tapped the dirt out. Came out in nice hard bricks. Like adobe. Not too great for plants.
I still take may chances buying topsoil from the nursery, but the main problem is getting the sacks home. I usually take a series of collectivos (taxi vans) back and forth from Chacala, to Las Varas (the local "real" town), and then down the highway to La Penita. Both nurseries are outside of town, so I get off the collectivo, do my business with whichever nursery I am going to, and then walk back across the highway with as many plants and pots as I can carry. But the sacks of soil are too heavy for me, and the drivers don't want to fill up the van with non-paying sacks of dirt. Then I reverse my trip back to Chacala, hoping the driver will bring me right to my driveway.
Since I can't get dirt the collectivo way, I am always looking for someone to help me get some sacks of soil, or pick some up for me. It's not easy to find someone wanting to do it. And sometimes it's a little awkward. Either the driver insists I not pay for their help or they want much more than I can afford. Or the person is doing me a big favor that would be hard to repay.
But the quality of the soil is still the main problem. Oh, for the days of sacks and piles of lovely black dirt, smelling good, and full of humus in my old hometow. There for the buying. I know I will figure out the dirt situation here, but it hasn't been easy.