By Bonnie Giddens, Bexar County Master Gardener Intern
October 2023
Urban vegetable gardening is experiencing a resurgence for a variety of reasons, and every gardener faces different challenges when trying to squeeze a vegetable garden into an urban landscape. Sometimes we need to think “outside of the raised bed box” that is the most common approach for planting an urban vegetable garden.
Can you mix a few vegetable plants into your existing flower beds? Or perhaps some well-placed pots among your flowers so the pots can be easily removed when the harvest is complete? How are you using the area outside of your fence? Or that abandoned corner near the trash cans?
To the right is a photo of my vegetable garden after this summer’s horrendous heat, squeezed between the fence and the curb in one direction and the power poles and garage in the other.
Let’s familiarize ourselves with some of the more common terms and/or methods for gardening in small areas.
Double-cropping or Succession Planting focuses on planting multiple crops in a single growing season. Plantings are staggered to ensure a continuous harvest and replanted with a new crop as soon as possible after harvesting. San Antonio has a great climate for using this technique.
Intensive Spacing focuses on growing plants as close together as possible to increase harvest for a given land area, reduce weed pressure and water evaporation, while spacing plants far enough apart to maintain airflow to deter disease.
Intercropping focuses on combining plants in a logical pattern based on certain traits. Traits to consider include plant height and breadth, length of time to maturity, root depth, shade tolerance, and ground cover. Intercropping can even be used to plant crops that benefit from the companion crop and increase the overall yield for the given amount of land, as shown in a TAMU study “Harvest Gains from Intercropping” by Jose G. Franco and Joseph G. Masabni.
The Square Foot Gardening method by Mel Bartholomew incorporates some of the techniques of Intensive Spacing and Intercropping. I use a combination of intercropping, intensive spacing, and succession planting. Following are some examples of ways I’ve maximized yields from my small urban garden.
- Plant crops that root deeply such as parsnips, carrots, and tomatoes next to shallow root vegetables such as broccoli or lettuce. Vining plants can take up too much ground area in a small urban garden, but most do very well on trellises. This makes the ground available for underplanting low-growing plants, or a plant that will thrive in the shade of the vines.
- I use the following two techniques the most. I focus on planting heat-tolerant vegetables (like peppers and eggplant (in between cool-weather vegetables (like lettuces, kale, chard, or mustard greens) that stop producing when temperatures rise in May or June. All the cool-weather vegetables will be harvested by June and the eggplant can grow through July and into August with plenty of space for airflow. I plant okra last in the spring and plan for it to fill some of the areas where I remove the cool-weather vegetables. Okra tolerates the heat the best and some years will produce into the fall. As it gets taller, I cut back the lower leaves to make space for the fall/winter plantings that get established beneath the okra.
- I also think about the length of time to maturity. Lettuce matures quickly and can be harvested by the time long-maturing green beans or peppers take over the space. Radishes can be planted almost anywhere because they mature so quickly. Leeks take a long time to mature, but they don’t mind being in the shade of other plants and take up very little ground area. The nasturtium and lettuces in this photo will be harvested and die back by May or June when the green beans will peak, and then the peppers can take over this space into July and August.
A benefit to intercropping is that you can be selective about what to replant when things come up sporadically. You can plant more of the same seeds and extend your harvest season, or you can plant something new in between. Celebrate the volunteer plants, especially things like arugula and cilantro and just eat them when they get too big for the spot they chose.
One challenge with year-round gardening is the need to manage pests and maintain soil health. The more I focus on soil health, the fewer pests I experience. I learned this the hard way when I started finding nematodes on my okra roots at the end of the harvest. I now plant a little tuft of Elbon Rye seeds each time I pull up a plant. The photo to the left is what it looked like right before I planted it in the spring. I pull the Elbon Rye and mix it with my compost. I also intersperse marigolds throughout my garden. I’ve only had one issue with nematodes since I started this practice, and it was because I left some beets in the ground too long before harvesting. Another benefit to growing a small urban garden is that you can experiment with pushing the boundaries of the growing season. If we get a one-off early freeze or late freeze, it is easy to cover the compact area and protect the plants. This generally enables me to maintain my vegetable garden year-round. The following photos show my garden layout as of March 2023. I wouldn’t say it was the best layout, but each year is different, and I embrace the unexpected.
Additional Intensive Gardening Resources:
Harvest Gains from Intercropping
Intensive Gardening Techniques
All photos by author