Fall is in the air, and all of the colorful, curvy and warty varieties of pumpkins are making an appearance as Halloween grows near. I love growing pumpkins, but I don't love how their long vines take over everything else in my veggie garden. For several years I wished that I had more space so that I didn't have to choose between growing pumpkins and something else in my limited garden space until I figured out the perfect solution! A Hugelkultur raised bed has been just what I needed to add a designated space for growing pumpkins. What is a Hugelkultur you may ask? Hugelkultur is a German word meaning hill culture or mound culture. It is a traditional farming technique used for centuries in Eastern Europe and Germany which utilizes large pieces of wood and plant waste to build a deep, nutrient rich bed requiring minimal irrigation and fertilization. The basic premise of the technique is that as the wood and other biomass decays, it retains moisture and supplies nutrients to the mound. I hope you'll give it a try - I've really been happy with how it's worked for me! Here's a step-by-step guide for adding a Hugelkultur to your garden.
The size of the Hugelkultur can vary depending upon your space. A rectangular bed that is at least three feet wide and six feet long is a good size, or alternatively, you can build a round bed that is six feet in diameter. You will want to find a location that is large enough for constructing a big mound with room around the mound for the plants growing in it to thrive and spread out. As with most gardens, you’ll want to find a sunny location for your Hugelkultur. Hugelkultur beds are well suited for using in areas with compacted or poorly draining soils that can pose a challenge to gardening. I selected a site in full sun in a neglected area of the yard with heavy clay soils.
It takes at least a couple of seasons for a newly built Hugelkultur to begin settling and breaking down the organic materials that is necessary to form the deep, moisture retentive soils that are the key to success of this technique. The end of summer is a good time to assemble a Hugelkultur so that it will be ready for next year’s gardening season. As you are chopping firewood, pruning trees, and trimming the garden you can set some of these materials aside so that you’ll have everything you need to build a Hugelkultur.
The Hugelkultur is constructed in layers using varying sizes of organic materials. The bottom layer is constructed with the largest sized materials, and it should be built with logs or thick branches. This is a great use for odd sizes or shapes of woody debris. Partially rotten wood that may not be ideal for using as firewood is also a good choice for building a Hugelkultur. Avoid using species known to inhibit the growth of other plants through allelopathy such as walnut, and also avoid species that are slow to decompose such as cedar. The second layer is built with smaller diameter branches and twigs. Leaves and wood chips can also be used for the smaller sized materials. The third layer should consist of nitrogen rich materials that will break down quickly to provide nutrients and retain water. A variety of materials can be used in this layer such as manure or compost, kitchen waste, grass clippings, or garden trimmings. Be sure to avoid anything containing weed seeds.
When the Hugelkultur is finished it should be a minimum of three feet tall, so keep this in mind as you are building the bed. The bottom layers should contain a substantial amount of woody material. As you add each layer to the Hugelkultur, try to nestle the materials together and push them down a bit. Water each layer after it is placed on the Hugelkultur to start the decomposition process. The third layer should contain a few inches of top soil or dirt to cover the other materials in the bed. Finally, cover the whole mound with mulch. You can also use straw or wood shavings, whatever you typically use for mulch in your garden will work. Now that you’ve assembled the Hugelkultur, you will leave it to sit over the fall and winter to settle and start decomposing.
In the spring or summer when you are ready to plant, be sure to check that the materials have settled sufficiently so that there are no large gaps or air pockets in the upper portion that could leave your seedlings high and dry. You can use a stick or a trowel to tamp down the planting area before planting, and you may also want to press a little bit of compost in and around your plantings or seeds to ensure good root contact with the soil/compost in the upper layer of the Hugelkultur. Although the ultimate goal of a Hugelkultur is to not have to water it, or only water minimally, I recommend watering it occasionally during its first year because it takes time for the organic materials to break down sufficiently to provide deep moisture-retentive soils.
If deer are a problem in your garden or if you have free range chickens, you may want to protect your Hugelkultur by putting up a fence around it. You can make an easy fence using steel posts and chicken wire. Fasten the two ends of the chicken wire together loosely so that the fence can be easily opened as needed. You'll want to occassionally open the fence to pull any weeds and check the soil to make sure your plants have enough moisture. I also wind my pumpkin vines around the mound to keep them from growing through the fence. My Hugelkultur pumpkin patch has been quite a success. I hope you will find this traditional agricultural technique a welcome addition to your garden!