Growing Root Vegetables… on a Balcony!

Yes, it’s satisfying to grow tomatoes and basil on a city balcony. But there comes a time in life when you’re ready to take your urban farming project a step further. And that’s when our eyes turn to radishes, beets, carrots, turnips and rutabagas. Hey, maybe some parsnips too?

Instinctively, root vegetables aren’t what comes to mind when we think of urban vegetable gardens. However, they are very easy to grow in containers, as the potting soil, with its light and loose properties, allows the roots to grow without constraints. Only parsnips can pose a slight additional challenge, as the roots are very hungry for organic matter and go deep into the soil. The problem to watch out for when growing root vegetables comes mainly from the heat and lack of water, which are more common for potted plants. However, this pitfall can be avoided by choosing shorter or smaller vegetables that mature a little earlier than what would be recommended in the ground.

What Vegetables to Grow?

There’s plenty to choose from. Since all root vegetables are sown directly outdoors, you can choose your varieties and order seeds from just about anywhere. Sowing is done one or two weeks before the end of the frost period, which is around May 10th in the Montreal area.

Indoor sowing doesn’t extend the growing season, as the roots are often damaged during transplanting, and seedlings grown directly in pots quickly outgrow their rivals. In the case of carrots and parsnips, watering shouldn’t be abundant, but very constant to allow the seeds to germinate. These seeds can take two to three weeks to show signs of life. This is not the case for radishes, which germinates in four days and are ready to harvest four weeks later. Beets take 5 to 10 days. Turnips and their close relatives, 5 to 7 days.

The Radish, a Great Favorite

Of all the root vegetables, radishes are undoubtedly the easiest to grow successfully in containers. First, because they can be sown very early. Their cold tolerance is also good for late fall sowing. Second, because of their rapid growth, they don’t need to be tended for long periods of time to achieve results. As mentioned earlier, regular watering is important. Frequent water deficiencies result in fibrous and less sweet vegetables. Oh, and full sun is required for good growth, though smaller varieties will thrive in partial shade.

Most root vegetables can be grown in any type of container. But for carrots, parsnips, and daikon radishes, it’s essential to grow them in a container that’s at least 30 cm (12 inches) deep. That said, dwarf carrots do very well in a simple rectangular plastic planter. For these vegetables that like to be buried, like carrots, keep a handful or two of potting soil aside to add more if the vegetables’ shoulders become bare.

Ready to Eat?

You can’t tell if a root vegetable is ready to harvest by looking at its foliage. You have to carefully dig up the base of the leaves to get an idea of the vegetable’s diameter.

Regarding carrots, they can be left in their pots until very late in the fall. In fact, they even taste better when harvested after the first frost. But you shouldn’t wait too long either, as frozen soil hardens quickly in a container. In fact, if you’re aiming for a very late harvest, it’s best to grow carrots in black felt pots, fabric pots, or plastic containers. Terracotta pots can burst in the frost, and they should be stored in early October. Add to that a small sowing of radishes in the first week of September, and you can safely say that root vegetables are a great way to extend the urban farming season to its fullest.

And while you’re growing vegetables from seed, why not get creative and grow colorful carrots, yellow beets, and white radishes? They look great on the balcony, on the plate, and they taste great!