Perhaps the bane of even the most zealous city dweller is a lack of green space in which to grow plants. But almost all dwellings have balconies, decks, patios, courtyards, or even access to flat rooftops. These areas are ideal for container gardening. Large containers planted with fruits, berries, and herbs provide a beautiful and functional gardening space.
A “food forest” is an edible landscape modeled after the layers of a forest. Trees, shrubs, perennials, groundcovers, and vines grow together in one container, with each plant layer having enough space, above and below ground, to thrive. Fruit trees form the upper canopy, berries grow underneath the trees as the shrub layer, herbaceous perennials grow among groundcover, and vines climb up the tree. A food forest can be created in a backyard with three to five fruit trees or on a parking strip with two trees, surrounded by berries, flowers, and herbs. For those with extremely limited growing room, a wine barrel planted with a variety of edibles makes a wonderful urban food forest.
The Container: A dwarf fruit tree requires a fifteen- to twenty-gallon container. Old wine barrels are excellent because they are wide, not too deep, and drain well. If you plan on moving the container inside in the winter, put it on wheels or a dolly before you plant it, or use a container with handles.
Soil: Light and free-draining (a sand, peat moss, compost, and loamy soil combination) is best, with some nutrients. Bagged potting soil mixed with compost works fine. Avoid heavy garden soil and clay, as they tend to hold too much water.
Planting: Fill the barrel with enough soil to reach the tree roots you are about to plant. Set the plants in the container and back fill with more soil. Larger root balls and bare root plants should go in first, followed by one-gallon and smaller plants. Add soil with each layer of plants until it is approximately three to four inches below the top of the container. Don’t bury the plants—the root crowns should be level with the container’s final soil line.
Maintenance: Don’t crowd too many plants into one container. The average wine barrel can easily grow one dwarf fruit tree, one small berry bush, one herbaceous perennial, and one groundcover, with room left over for annuals or edible flowers. As the plants fill out, annuals will often be crowded out. You may have to thin the herbaceous perennial and perhaps the groundcover as they expand their footprints. Mint, bee balm, and strawberries can quickly colonize the barrel. Raspberries should be maintained at two or three fruiting canes.
Watering and fertilizing: Containers tend to dry out fast, so check the soil’s moisture level often. Daily watering in the summer is not unusual, but be sure not to overwater (the soil should be damp, not saturated). Water running through containers tends to leach nutrients from the soil faster than in traditional garden beds. Use a soil mix that contains compost, and add fertilizer in the form of compost, liquid, or granules once a year.