Assess your soil
The first step in building a garden is to assess your soil for possible contaminants.
Gardens can include physical infrastructure, ranging from a simple shed for tools to raised beds, hoop houses, greenhouses, and cold frames. More involved infrastructure might include community gathering places, produce stands, and food preparation areas. Garden design links together this infrastructure to support your garden goals.
As you sketch out your design, think about the physical elements at your site. Consider the direction of sun and wind exposure. Will you have good access to water with your design? Factor in the influence of adjacent buildings and trees, as well as low-lying areas prone to flooding. You should also consider the proximity to the street and entrance.
Most likely, you want to organize everything around your primary goal of food production. But even the production area design will be dictated by your garden structure: Is it a community farm where everybody works the beds together, or do gardener work individual plots? In any case, locate the production beds in an area with good sun, lower wind exposure, and good water access.
beds: to raise or not to raise?
As you design your production area, think about bed layout and whether or not to make raised beds. Raised beds can range from paths between soil mounds to shallow boxes resting on the native soil. They can even be boxes several feet tall physically separated from the native soil.
The type of raised bed you choose will be based on your native soil. If your soil is contaminated, consider raised boxes with imported soils. Or perhaps you have a weedy area in an uncultivated vacant lot. This soil may have a relatively high amount organic matter, and be ready for you to cultivate. Poor quality soil--soil with low organic matter that has been compacted by traffic or other factors and is full of weeds--will need rehabilitation. Think about the energy it will take to fix poor quality soil and the time you’ll be able to work at the site, in comparison to the money and labor it takes to build raised beds.
Here are some pros and cons about raised beds to help you with the decision:
- Appearance. If the appearance of the garden is important (for example, it’s on a busy street corner or located on public property), consider building raised beds. Even if they are full of weeds, they have a more “tidy” look than in-ground gardens.
- Ease of gardening/accessibility. If the soil in the garden is hard to work or several gardeners struggle to bend over, you may want to consider raised beds. Often the soil is easier to work, there are fewer weeds, and you can construct beds to be of a height that’s easier to work for gardeners with limited mobility.
- Cost. The cost of raised beds makes a garden much more expensive to build. If cost is a limiting factor, you may want to consider amending the existing soil rather than bringing in the soil for a raised bed. You could also go with simple mounded beds with high-quality soil.
- Existing soil quality. Sometimes soil in urban areas has been neglected and can take several growing seasons to rehabilitate. Importing soil from elsewhere can be a way to speed up the time to a productive vegetable garden. Make sure you import good quality, uncontaminated topsoil.
- Reduced risk. In some areas of cities, soil contamination can be a factor. If you suspect high levels of heavy metals in your soil, build raised beds and mulch all surrounding soil to reduce your risk. Be sure to test raised bed soil after a few years, since even soil in raised beds can become contaminated by aerial fallout from local industries and chipping house paint.
- Skilled labor. While they are not complicated structures, raised beds do require some construction skills. If your garden does not have volunteers with these skills, either reach out to the community for assistance or build your garden on the ground.
- Water dynamics. Raised beds can dry out faster than native soil. Depending on your climate and local drainage, this can be a pro or a con.
Lay out your garden with pathways to success
Well-designed garden paths invite people into the garden and make moving materials easy. Plan paths and reasonably-sized garden beds so gardeners can access the bed without stepping directly on the soil. Over time, stepping directly on your bed soil compacts the soil. This leads to poor water infiltration, and issues with drainage and air flow–which impedes plant growth. Popular bed designs include three-foot wide rectangular beds, curving beds, and circular beds with keyhole paths for access. Leave plenty of pathway space in between for wheelbarrows, wheelchairs, and groups of people.
Pathways should be covered or mulched to protect from erosion and dust. You’ll need to consider the type of mulching material. If your garden is to be truly accessible, the paths should be paved with paving bricks. Paving bricks allow for good mobility and also keep the soil underneath connected to collect rain and snowmelt. Mulch paths with woodchips (often free from local arborists) to prevent weed growth and keep down dust, especially if the soil is contaminated.
This is also a great time to think about how you will water the garden. Rain with occasional sprinkler use? Drip irrigation? The right garden design can make watering easier, whether that means beds that are all the same size so they all take the same length of drip tape, beds that a sprinkler can easily cover, or a nice wide path for pulling the hose.
Other garden infrastructure
Sheds are indispensable for secure and dry tool storage. Check with your local building permits office to see if you need a permit to build a shed. In many cities, you can build a shed with a roof area less than 120 square feet without a permit.
Fences control access, so think carefully about who you want to feel welcomed to the garden. Fences can help you control when people have access to your garden and may provide some safety. Some research shows that community members feel most ownership over unfenced gardens, while in other areas community members prefer gardens to be fenced and closed overnight. Still, other experience shows that beautiful tomatoes and heads of broccoli might disappear regardless of the presence of fences. There are not always easy answers to these questions, but thinking carefully about your garden goals and how your garden fits into the surrounding community can help. Fencing might require a permit, sometimes depending on height--for example, if it is over five feet tall.
Of course, there are some things you don’t want to welcome in your garden. Controlling access of animals, whether deer, rabbits, gophers, turkeys, or geese, requires specialized fencing and possibly netting. In particular, fencing in poultry and duck areas to prevent predation from raccoons, hawks, and possums can be a bit of an art.
Greenhouses are extremely useful for starting seeds and extending your growing season. Again, check with your building permit office, but you will probably not need a permit for a small structure or a structure that is not considered permanent, like a hoop house or high tunnel over your beds. However, if you’re going to put up a larger hoop house, we suggest checking in with the neighbors first!
Food preparation areas and farm stands are great ways to celebrate the food you produce and share it with others. Produce and handwashing areas can be low-tech and simple to install. Be aware that anything involving food preparation invokes a host of food safety regulations. Check local regulations carefully to make sure you meet food safety and vending requirements. Some cities are enacting progressive regulations to make it easy to prepare and sell food produced in community gardens, but others have codes regulating this activity. It’s best to check with your local officials. Selling produce is often easier to do than selling value-added products, like pickles or jam. However, these value-added products can bring in more income and create more jobs.
Community gathering and education spaces at urban farms can be anything from meeting areas to amphitheaters to outdoor classrooms. Urban agriculture spaces can play an important role in building community, so consider including space for people to gather. This can be a simple picnic table for garden meetings and sharing food or a more developed area for community events.
Restrooms and handwashing stations are a good idea and required by the city as you add in food preparation areas and community gathering spaces. As always, municipal codes apply.
Overall, there are so many great ways to design your garden! You can start small and work up to bigger dreams. You might have noticed a common theme of city permitting in the above descriptions. Working with city regulations is not always easy, but fortunately, many cities are working to make the process easier for urban farmers and gardeners. If your city is not “up to speed,” consider getting involved in helping to write local legislation that works in favor of urban farmers and gardeners. (Read about Montreal's journey in community gardens, here.)
For more information on keeping your raised bed healthy, read this article about raised beds in SSSA's Soils Matter blog.
To watch a video about soil compaction, click here.
Next...Amending the soil