Polyculture vs Row Culture

Last year I was inspired by reading some permaculture books and decided to experiment with sowing a polyculture planting in part of my backyard raised bed. I based mine on the polyculture sowing described in Toby Hemenway's "Gaia's Garden."

In a broadcast fashion I sowed a couple varieties of lettuce, arugula, spinach, dill, parsnip, radish and a 'brassica mix' which included red russian kale and mizuna.

The idea behind polycultures is that the multiplicity of different plants, especially aromatic ones such as dill, helps to lower susceptibility to pests and disease.

While this may be true, I found my polyculture bed difficult to weed and harvest from. I think this partly stems from the fact that I am a person who likes order. To me, once the polyculture sowing sprouted it represented chaos, and this was difficult for me to get my head around.

The plants grew at different rates and I wasn't able to cut greens as easily as I was used to in the neat linear rows on the farms. What I read about polycultures told me to harvest whole plants instead of cutting, in order to make space for other plants to flourish. I did do this, but there's something I like more about getting 3 cuttings off of my lettuce before pulling it and letting it break down back into the top soil.

I can't help but think: what does this say about me if I didn't enjoy my polyculture experience? Polycultures mimic the diversity, chaos, and beauty of nature and of the forest. Am I dishonouring nature by growing my greens in straight lines this year? My answer is no; through companion plantings, albeit sometimes in straight lines, I maintain the pest and disease resisting characteristics of polyculture plantings. Plus I am producing more greens.

I do grow lots of other crops together; strawberries with onions & spinach, peas with carrots, tomatoes with basil, lettuce, parsley & marigolds. I view my entire backyard as a polyculture. I just choose to grow my salad greens, and some other crops, in rows.

Rows are about efficiency when harvesting, and weeding, and this appeals to the order of my mind. While I may lean towards row culture, especially for some crops, I definitely do not subscribe to monoculture.

Hugelkultur

I learned about hugelkultur, a german word meaning "mound culture", in Toby Hemenway's book "Gaia's Garden: A Guide to Home-scale Permaculture."

Hugelkultur involves burying dampened logs, branches and twigs underneath layers of compostable materials, leaves, finished compost and topsoil. The resulting mound can be planted directly into.

This method offers several benefits. The wood holds a lot of moisture, accessible to plant roots for long periods of time, thus watering will be required less frequently. The logs, branches and layers of compostable materials offer habitat for soil organisms, and the slow decomposition of the wood will create healthy and fertile soil. It is a version of composting in place (like sheet mulch).

It is important to include nitrogen rich materials in the layers on top of the logs, and shoved inbetween them, since the decomposition of the woody materials will use a lot of nitrogen in the process. A good carbon/nitrogen balance can be maintained by including nitrogen rich kitchen scraps, fresh leaves, etc into the mound's layers. Also planting nitrogen fixing legumes (peas, beans) in the hugelkultur bed will also add nitrogen into the soil.

I decided to try it out in a specific area of my backyard garden. I placed the mound in front of a south facing fence. The hugelkultur bed will serve many purposes here. It will allow me to grow climbing varieties of plants up trellises along the fence, some of which prefer to be grown in mounds (winter squash). It will provide long term fertility to the soil in this area of the garden as the logs and branches decompose. It will improve water retention in the soil in this area. It's physical location allows the mound to act as a physical barrier preventing soil and water runoff into my neighbors backyard, due to the existing slope in that direction.

This is a good example of the permaculture principle of stacking functions - getting many yields from one element of the garden system. The hugelkultur mound provides space to grow climbing and mound varieties of vegetables by providing a niche for them, it enhances the main space in my yard where I can garden vertically, it improves water retention, soil quality, and prevents erosion. It will serve multiple functions in my garden.

Wooden debris at the side of my house becomes a resource for a hugelkultur bed

The finished mound. Approx 4 ft x 2 ft, 1.5 ft high.
Layers used include: logs, branches, twigs, sage plant clippings, kitchen scraps, peat moss, leaves, finished compost, and topsoil.

I plan to plant 1 winter squash (Delicata) and scarlet runner beans closer to the fence side of the mound, and 1 or 2 summer squash closer to the front of the mound. The winter squash and runner beans will climb the trellis and fence, the beans will fix nitrogen into the soil, and the large leaves of the summer squash will work as a living mulch to suppress weeds. I am excited to see how the bed evolves over the season and beyond.