By Liz Christy, Horticulturist

A watering harvest technique for sustainable gardening in a Southern California drought.

Many parents wonder how they can get their kids to go outside more. In this age of ever growing technology we go outside less and less. Even I find myself somedays on the floor of my living room watching Netflix and eating pine nuts instead of going for a walk or trying to conquer the ever elusive Mt. Wilson Trail. So here is a fun project, for either school or home, that involves science, biology, water harvesting and some good old fashioned manual labor.

I learned about the hugelkultur at the Los Angeles County Arboretum. Volunteering at their Crescent Farm, a garden space dedicated to drought tolerant gardening techniques, I helped build and plant one of the larger hugelkulturs. The word literally means in German “hill culture” and has been used for hundreds of years in European farming. This technique prolonged the growing season and was created by mirroring the natural decomposition process that takes place on a forest floor, hence imitating things in nature.

In Southern California where water is scarce it is especially difficult for those of us who want a lush garden. Using methods of hugelkultur or swales can increase the retention of ground water in your soil and drastically cut down your water usage while still having a lively colorful garden.

Start by digging out the space where you want the hugel built. I like using a crescent shaped hugel, but really any shape will be fine. For best results face the inside of your crescent towards the west. This will allow coastal moisture to be trapped in your hugel more easily. The base of your hugel should be about a foot deep. The depth and size really depends on how much wood you have. Look for someone in your neighborhood who has recently cut down a tree or contact a local arborist.

Lay the wood in the base you have dug placing the largest logs on the bottom facing upright. Fill in gaps with smaller logs, sticks, woodchips and finally soil. Cover the entire mound with a foot of organic soil. Once plants are installed mulch generously to add an extra layer of protection. The density of the logs will create condensation as temperatures rise and fall over a 24-hour period. This will water your plants from underneath. You will still have to soak in your newly planted things but the hugel will use the wood to retain the moisture. Over time the wood will break down added nutrient rich material to the soil. This will also create small air pockets to oxygenate the soil created beneficial aerobic microorganisms. These organisms will allow your plants to use the nitrogen in the soil.

You may still have to water your plants during the hottest part of the summer, especially if your hugel is not very large. The bigger the hugel the more water it will retain. During winter months there is no need for water at all, just the occasional rain will be enough and in the summer you may only have to water once a month. Each hugel is a little different so your experience will be contingent on how you build.

Good luck on your garden projects!