As mentioned in the last article, when I arrived here in Costa Rica in 2009 I was confronted by an array of problems. I had to come up with a solution for each and every one because each was serious enough to negate my entire effort (with the exception of #1 below). In other words, it was going to be “game over.“
Here is a list of the problems and their solutions:
- Constant heavy rain in September and October – Solution: don’t garden during those months
- African star grass – Solution: smother it with black plastic
- High winds – Solution: construct wind breaks and plant trees
- High annual rainfall – Solution: plant the vegetable garden in raised beds
- Dogs – Solution: build a fence
- Terrible soil (a combination of clay mixed with construction rubble) – Solution: dig up the “soil,” THROW IT AWAY, and start over using (A) good topsoil and (B) begin improving the soil using compost and other material
One thing I’ve learned over the years is the absolute necessity of good soil. I can’t emphasize this enough. If all other conditions are perfect, but you have lousy soil, you might as well pack your bags and go home. And, I’ve discovered, many people really don’t know what good soil is, and couldn’t tell the difference between good and bad soil. To them, dirt is dirt.
High clay content is usually the problem. Plants need loose soil, full of organic material, so they can extend their roots out as far as possible in order to soak up as much water and as many nutrients as possible. Also, plants breathe through their roots. Clay prevents plants from doing both these things. It’s really quite simple; poor nutrition
means a non-productive plant; roots that can’t breathe means a dead plant.
Here are a few tests to check the clay content:
- If the soil has a reddish – orangish color, it probably has a lot of clay in it.
- In the dry season, try pushing a spade into the soil, if it won’t go in, you might have high clay content.
- In the wet season, push a spade into the soil, scoop some up and try to dump it out. If a lot of it sticks to the spade, it probably has lots of clay in it.
- Wet your soil, scoop up some with your hand and squeeze it. When you release it, if it sticks together in a solid mass it’s probably clay. Another way is to roll some of the soil into a ball. If it has high clay content, you can make a pretty good ball. Good, loose soil with high organic content cannot be rolled into a ball.
If you should have high clay content, you don’t have to come up with a solution as radical as mine (i.e., dump it and begin from scratch). You can work with it, incorporating beneficial material and improve it gradually over the years. I did actually keep some of my clay. Clay tends to be fertile, but it’s the structure of it that doesn’t allow plant roots to grow and breathe.
Here is a list of things I incorporated into my soil:
- Topsoil (tierra negra or tierra de cafetal)
- Construction sand (arena fina)
- Rice hulls (granza)
- Compost (compos)
- Horse, cow and chicken manure (estíercol de caballo, vaca, and cuita de gallina)
- Charcoal (carbón)
- Wood ash (ceniza)
- Earth worm castings (compos de lombriz or lombri-suelo)
You can purchase topsoil, rice hulls, and charcoal at good nurseries. EPA and good plant nurseries carry worm castings (you can also make it yourself). I wanted quantities by the truckload, so I had to ask around. Sand, of course, you can get at building supply stores.
I could expand ad infinitum on these recommendations for improving your soil, but let’s just regard this as a crash course on soil improvement.
As for Costa Rica’s wonderful volcanic soil, that is somewhat of a myth. Most of Costa Rica does not have volcanic soil. True, the area around Cartago and Turrialba is famous for its rich volcanic soil. Where we live, on the side of Cerro Chompipe in the Cordillera Central, there hasn’t been a major volcanic eruption for at least 250,000 years. With an average annual rainfall of over 100 inches, you can imagine the effect that has had on the volcanic soil.
In the next article we’ll begin to discuss growing individual types of fruits and vegetables.
- Gardening in Costa Rica with Steve: The Challenges
- From the Peace Corps to Retirement in Costa Rica, by Steve Johnson