Container Vegetable Gardening
Growing vegetables in containers is a rapidly expanding trend here in the US and vegetable hybridizers have taken notice. There are currently varieties of every type of vegetable available that were created for growing in containers, making it easier than ever to try.
The first, and in some ways the most important part, of container gardening is the container itself. Containers can be made from a variety of materials including clay, plastic, cloth, wood, concrete blocks or even wire baskets with sphagnum moss as long as the container has never contained any toxic chemicals. Some of the cheapest options of containers can be storage totes, five-gallon buckets, protein tubs from livestock or even old swimming pools your kids have outgrown. The key is they need to be a minimum of 6 inches deep and they have to have drainage holes, which you can easily add yourself. Avoid dark colored pots because they tend to heat up faster and the heat can damage the roots of your plants. Large vegetables such as tomatoes, squash, watermelon and corn will need containers that are a minimum size of a five-gallon bucket. The bigger the container, the more room for roots and the cooler the roots will stay with more soil to buffer the temperatures. If you are worried about your plants drying out during the hot summer days, there are self-watering containers that can be purchased or similar to the one in the picture down below, they are easy to make.
Once you have a container, the next step is to figure out where you are going to put it. Fruiting vegetables need 8 or more hours of sunlight a day while root and leaf crops need approximately 6 hours minimum of sun. Figure out where you want to put your container so that it will received the maximum amount of light possible. You should figure out where you are putting your containers before you fill them because they get very heavy once filled up. A word of caution, water from the containers can stain decks. To prevent staining, you can use saucers to catch excess water (which can help prevent angering your neighbors if you live in an apartment) but they do need to be emptied after a rain or watering so the plants don’t stand in water.
The next step once you have a container and know where you are going to put it is to fill it up with media of some kind. Whatever media or mix you use it should provide nutrients for the plant, hold moisture, allow for maximum root growth and support the plant so it doesn’t fall over. I will never recommend to use just straight garden dirt or top soil in containers. It tends to turn to a rock as it dries out and become compacted so the roots can’t grow through it. You can use top soil that has been pasteurized as part of a mix but it should never be more than 10% of the mix and only use it in big pots or raised beds. A peat or coco coir based potting mix is your best option for containers in combination with compost. This combination is lighter in weight but will hold adequate water for your vegetables to grow. You can re-use your soil for several years, as long as you didn’t have any major disease issues. I would refresh the soil every couple of years by adding in new compost or potting soils to replace the nutrients used by the plants every year.
The final step is what vegetables can I plant in a container? You can grow any kind of vegetable in a container you would grow in the ground. When looking at varieties find ones that are labeled “dwarf” or “bush” varieties. There is a wide array of varieties that have been developed strictly for containers and they are usually labeled as such. Tomatoes, peas and vining crops will need some support to grow. A tomato cage or trellis can help keep them contained and from sprawling everywhere on your deck. Click here for a list of recommended varieties for containers.
As with all container plants, your vegetables will need watered on a regular basis, especially later in the summer when we get really hot. One way to reduce the amount you have to water is to put a mulch layer down over the top of your soil to reduce evaporation and help keep the soil cooler. Fertilizer will also be necessary to keep the plants producing all summer long. I typically mix a slow release vegetable fertilizer when I put my soil in the containers. This way my vegetables get some fertilizer every time I water. I’ll fertilize every couple of weeks with a water-soluble general fertilizer (10-10-10 or 14-14-14) once the plants start to set blooms and produce fruit. I tend to wait to fertilize my tomatoes till they set blooms because I want them to produce tomatoes, not just grow really impressive tops, which I have had happen. I do try to “flush” the soil periodically by watering it thoroughly till the excess water runs out to prevent the buildup of salts from the fertilizer in the soil. Keep an eye on your plants for disease, insect and nutrient issues. These can usually be corrected but it’s easier to fix if you catch it early.
Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.
Phone: (316) 321-9660
Email: callae@ksu.edu