If you want to make your gardening mile go farther in Philly, one of your best options is to build a raised garden bed. Raised beds give you more space than using containers. They also eliminate the risk of growing edibles in soil that is contaminated with lead or other heavy metals, which is all too common in Philly. Planting a raised garden bed also lets you get a jump on the growing season, since you don’t have to wait for ground soil to thaw out.
Where you build your raised bed is a source of debate. Some might say that you should only build it on top of soil, since doing so allows water to seep into the ground and prevents the bed’s soil from becoming too soggy. However, a lot of yards in Philadelphia are made of concrete, so you may need to build a raised garden bed on top of a sidewalk or concrete surface. You just have to remember to add rocks or another material below the soil to allow for drainage.
It’s important to make your raised bed narrower than it is long. A garden bed shouldn’t be wider than four feet or you won’t be able to get to the plants in the middle of the bed. In a small city yard, you might want to make a bed that’s even narrower, such as two feet wide, especially if you’ll be putting it against a wall and won’t be able to access it from one side. You can make the bed as long as you want, as long as you have room. To give the roots of the plants enough room to grow, make the bed at least twelve inches deep. The higher the bed is, the easier it will be to get into.
You don’t have to be handy with a drill or have any woodworking skills to make a raised garden bed. If you do decide to build a traditional bed using wood planks, pick wood that hasn’t been pressure treated, as the chemicals in pressure treated wood can leach into the soil.
You can just as easily make a garden bed from a number of other materials. One option is to use concrete cinder blocks. The blocks make an attractive bed and are pretty cheap. Stack the blocks with the holes facing up so that you can also plant in the holes. You can also build a raised bed using bags of sand that are stacked two high.
Inside the Bed
Building the soil mix inside the bed is critical for the health of any plants you grow. If you built the bed on top of concrete, spread a layer of rocks in the bottom of the bed, several inches thick, to promote drainage. Use a mix of garden soil, compost, and perlite or sand for the soil mix. Add each component to the bed in layers. You can get free compost from the city’s recycling center in Fairmount Park year round.
The most exciting part of building a raised garden bed might be picking out plants for it. In Philly, there are a number of places to get plants, from flowers to vegetables and from herbs to shrubs. In Kensington, Greensgrow Farms has an extensive nursery that offers heirloom vegetables and native plants. On Passyunk Avenue in South Philly, Urban Jungle also has a great selection of plants. Plan what you’ll plant based on your tastes and the seasons.