Growing Radishes in Containers

I pulled these Cherry Belle radishes at the end of September, not much more than a month after planting. These were all about 3/4 inches in diameter: just right for cherry belles.

My past attempt at growing radishes in containers on the balcony never worked out for me. Maybe one in every four would actually mature and form a round radish bulb. They usually took too long to grow, din't grow big enough and never tasted that great. But recently I figured out what was wrong.

Radishes require is a constant supply of water. If allowed to dry out they will develop a sharp and woody taste. To grow tasty radishes they need to be grown fast. In hot weather they bolt and after this happens they just don't taste right. By providing them with lots of what they need to grow you'll ensure they reach maturity before they bolt. I've found that this is more of a problem with radishes grown in the spring. In the fall, temperatures drop as the crop matures and you don't have the same problem with bolting.

I picked these white icicle radishes in November, after a bit of snow and a frost or two. The cold weather really slowed their growth.

But something that really improved my success with container grown radishes was the realization that they need to grow under overhead sunlight, or as close to overhead as you can get. This is not a problem in a garden or even a container on a patio. But on a balcony with an overhang, you don't get overhead sunlight. I wasn't able to grow decent radishes until I moved my containers out to the edge of the balcony away from the building wall. Out there they got much more light from above. Not exactly overhead but close enough during part of the day.

A couple of exotic radish varieties, by North American standards: Watermelon and Black Spanish. I grew these together in the same container.

This same lighting principal applies to any root crop, like beets or carrots for example. If the sunlight is always shining from the side, your plants will want to grow tall and lanky in an attempt to get as much sun exposure as possible. This causes the roots to extend out of the soil and also become long and skinny. But with overhead sunlight, the plants remain compact and the root, the part you want to eat, stays in the ground where it will form into a proper vegetable.

There are lots of radish varieties but two of my favorite "different" varieties are Black Spanish and Watermelon. I've also grow French Breakfast, White Icicle, Red Crimson and Cherry Belle - all in containers on my balcony.

Black Spanish radishes are not really black, but more of a dark brown. When wet and viewed in the right light though, they look very black.

The Black Spanish radishes I've grown were the round variety. The largest was close to three inches in diameter. They came out more pear-shaped than round. The skin was rough and not anything like typical North American garden radishes. The bright white flesh inside contrasted nicely with the dark outer skin. Being larger than a typical garden radish, these things need a bit more room to grow. I planted mine about six inches apart which is about twice the spacing I use for the smaller radishes. The tops on these radishes are also quite long. And unlike small varieties, these need more time in the ground: about two months.

Black Spanish radishes are big container vegetables, but not that big. I grew mine in a ten inch deep container. My only problem with the black spanish radish is the heat. I'm used to having small bite sized radishes I can just pop into my mouth. But these had to be sliced and the skins are rough. I found these radishes simply too big and too hot to be enjoyed as a snack.

It's this redish pink interrior that gives the Watermelon Radish it's name.

Watermelon radishes are something of a "gourmet" radish if a radish could ever be considered that way. The skin is suppose to be green and the inside red, hence the name watermelon radish. Like the black spanish radishes, these are much bigger than typical garden radishes. Mine grew to the size of large eggs. And they did not develop green skin - they were smooth and white. I planted them about six inches apart in a ten inch deep container and it took them almost two months to reach a "mature" size. Watermelon radishes are a Fall variety although you could probably attempt growing them in the spring. I suspect the time they require in the ground would mean they'd encounter hot summer weather and bolt before reaching an edible shape and size.

The colour and pattern of the inside of a watermelon radish is very interesting. But more interesting is the taste. These are mild radishes, almost sweet. I was rather impressed. Unlike the black spanish rads, these were quite snackable. Sliced, they would easily liven up any salad. I found a touch of vinegar made the colours even more vibrant and the taste a wee bit sweeter.