Murrieta, CA Sunken Hugelkulture with fruit tree and garden guild.

Hello friends!

A friend of mine has asked me to design and build her garden. She send me a photo of the Key Hole Garden. See Attached.

Here in zone 9b we deal with desert conditions. So I'm already planning on sinking this key hole ground down into the ground at least half way, if not 3/4 or ALL of the way down into the ground. I read a good report of a permie in the desert who was digging down 3 feet, filling about half wood chips, half compost, and making it nearly through the summer without water. So I want to get super ambitious and see if I can get down deep and thick enough to stabilize throughout the summer here in murrieta without artificial watering.

Please see my drawings. My plan is to go over there this evening to video and survey the space. I will post the video and my survey notes for this project soon. I appreciate your help with this design friends!

PEACE LOVE NATURE AND MUSIC
- ALEX MONK

What do you think about me using a Cherimoya tree at the center of the garden, with a nurse tree planted nearby to offer protection? Cherimoya is not a desert plant, it suffers from the high heat and low humidity, and then it is vulnerable to the frost. So I'm almost thinking I should build something like a huge grape trellis over the tree to provide some shade and humidity, or maybe just put it under a giant grandfather tree if there is space for that. What are your thoughts about the possibility of creating a microclimate for cherimoya in this garden? Or what other varieties would you recommend as a safer bet in this scenario?

Here is a more detailed overhead view. So you can see the berm surrounds the entire garden, then the swale is for walking. THe garden inside of that with compost chimney shutes, and then the tree planted in the middle.

And finally, my pipe dream, a huge geodesic dome trellis thing that is built over the fruit tree, to grow an evergreen fruit over... by trimming the ever green shrub or climber, we can maintain a 50% shade in the summer, and then trim it back even more in the winter to let more sun light through, but its still here to help protect against frost. Also the geodesic dome would be strong enough to climb all over so you can manicure the trim and harvest fruit easily like a big ladder system. What do you think of the geodesic pipe dream design? hahaha It says "grape" in the drawing but then I realized that is deciduous and wont protect the cherimoya from frost if the temps dip really cold so something evergreen and fruiting would probably be best. I expect there will also be a nice warm micro climate developing inside of this thing in the winter because of all the composing goin in there, so maybe citrus tied up to the dome trellis might be cool. Kumquat or something without the spikes would be preferable. Ideas?

I put woodchips into an above ground bed. I call it a semi-hugelkulture bed.... Seems some here cautioned against it, I don't remember... Raised beds take a LOT more watering than regular row crops, looks to me like. Your idea to bury it flush or 3/4 of the way sounds reasonable to me, esp. given your conditions. Have had our raised bed in production one season, seems to work OK. Been experimenting with biochar too. Just getting started with that, but if you're building a new bed, you might give it a look? Best, T

Here is a video of our friends backyard so you can see the space we are working with, lots of info in the video, I hope i shot it well enough to observe everything. Did my best. Ran out of battery on my iphone so video cut short.

http://youtu.be/TsPhcOJprSc

Tim Malacarne wrote:
I put woodchips into an above ground bed. I call it a semi-hugelkulture bed.... Seems some here cautioned against it, I don't remember... Raised beds take a LOT more watering than regular row crops, looks to me like. Your idea to bury it flush or 3/4 of the way sounds reasonable to me, esp. given your conditions. Have had our raised bed in production one season, seems to work OK. Been experimenting with biochar too. Just getting started with that, but if you're building a new bed, you might give it a look? Best, T

Tim, If you put wood chips under your compost, you need to make sure you put them way down under ground with A LOT of compost on top of them. The wood chips becomes a big place for drainage, and once the wood chips get a good soak then they become the sponge that holds moisture through the season If your wood chips are up high where they are not able to absorb the moisture, they will remain dry and so will the compost on top. The idea is to get the wood chis down below to soak up and retain the annual rainfall, then the compost "wicks" that moisture back up a little so the roots of the plants can grow down to this stabilized source of moisture. That's what I understand, correct me if I am wrong.

My challenge now is to understand how deep of a basin I should carve out below my hugel, how much of that should be filled with wood chips, and how much with compost? Based on my hot dry climate, and average annual rainfall of 15".

"Murrieta averages 15 inches (385 mm) of precipitation annually, which mainly occurs during the winter and spring (November through April) with generally light rain showers, but sometimes heavy rainfall and thunderstorms." Temps tip 100-105 in the summer consistently. Blllaaaahhhhhh ;p

One thought is to do a 30" deep pit with 18" of wood chips and 12" of compost. The bed would then be level with the ground and able to absorb any water that passes through the space. Then, to prevent drowning the plants to death after a heavy rain, Build a raised bed over that (MOUND) 6"-12" tall, made of compost.

Can anyone please refer me to a resource that will help me scientifically determine the correct size and shape of my swale + hugel structure for my climate?