#1 Hügelkultur
The practice of gardening with buried logs, or "hügelkultur," has become a popular meme in permaculture. Everybody wants to use hügelkultur beds. They retain moisture, give a home to beneficial fungi, and break down slowly into healthy soil. However, trying to do it just like Holzer did in the below drawing is not so workable in Florida. We have different challenges and issues than he does in the Austrian Alps.
These steep raised beds tend to not work in Florida because they get too hot, dry out more quickly, and degrade in the rain. The most successful way we’ve used hugelkultur is to bury the logs and build beds on top of them. This helps hold moisture in the sandy soil, it creates a great beneficial fungal system, it deepens the organic soil mass. The beds may sink as logs and limbs break down, but that is not something to resist necessarily.
We’ve used hugelkultur most successfully in swales in Florida. Because of the intense drainage of sand, water in swales tends to not spread so far and sink so slowly as it does in clay soils. Water can sink straight down into the sand instead of spreading downslope. By placing logs in the sand, we’re giving water a place to store itself near the surface, where roots can find it. We’re providing a foundation to build soil as well. Our swales start deeper, but as they fill with organic material, become more shallow, though still very absorbent. When they fill up, we can dig out some beautiful compost and throw it on the trees surrounding the swale, and still capture water in it. Another way to use logs is as "nurse" logs. Simply place them around the tree, no need to bury them though the organic matter that builds up around the tree could eventually bury them. By adding logs to your system, buried or not, you are mimicking the moist, protected, biomass rich microclimate of a forest floor.
This is just one way to use hugelkultur and swales in Florida. There are many other ways. The point is, these tools are site specific and your imagination plays a role! Think with the purpose of the tool and modify it to the needs of your project and landscape.
#2 Garden Microclimates
The below is an illustration of several ways to create soil building and water retaining microclimates in a kitchen garden. We’ve used these methods in orchards, food forests and windbreaks as well.
Mollison
We used mulch pits (A) created with a post hole digger for trees at Pine Ridge reservation, a dry plains system, to protect the young trees from wind and capture rain and nutrients. We also dug pits next to trees that we filled with organic material. This was very successful. The winds are very drying and would dry up any rain that managed to fall before it could soak into the clay soils. These pits allowed water to soak in, and water retaining nutrients to build up.
We use something similar to drawing (C) in Florida raised bed gardens, using the sides of beds as a more protected microclimate.
#3 Frost Protection
We sited our nursery between two buildings and large trees. During heavy wind events, like tropical storms, hardly any of the pots are knocked down, showing the effectiveness of buildings and trees as wind protection. This site also gets frost protection because of the overstory and warmth from buildings and trees.
We plant bananas and papayas under large trees which offers more protection from frost and freezing than being out in the open.
We planted a banana circle in a natural suntrap area that is also high on the land and near a driveway for extra thermal mass.
Bamboo, an oak tree and an RV parking spot, plus a compost windrow and driveway on the left provide a U-shaped sun trap for our newest banana circle, protected on the north and open to the south. A downhill slope on the right allows cold air to drain from the area.
Hands On Activity
Go to weatherspark.com and compare average temperatures and rainfall at Crescent City, CA and Yreka, CA. They’re at a similar latitude and less than 200 miles apart. Take a look at both cities on google maps and compare the microclimates. What has contributed to the differences?
Walk around your site and note the microclimates. This is one instance where the sit spot exercise can be very helpful. Use all of your senses to detect microclimates - temperature, humidity, wind, light, etc. Check different microclimates in your yard at different times, to learn more about how they work. Mark these microclimates on your base map.
Recognizing microclimates on different sties is a good exercise to do so you get very comfortable with it.
Also, note where there might be opportunities to create more microclimates with vegetation or water bodies, etc.