Help! Our radishes have bolted!

We were just getting over the shock of discovering that we really like radishes when our plants stopped producing the tasty and colourful edible roots that had become a regular feature on our dinner plates.

When we first sowed the aptly named Scarlet Globe back at the beginning of April, neither of us liked radishes. I’m not quite sure why we planted so many. We had new raised beds to fill and had somehow acquired the seeds, so thought we’d give them a go.  And thank goodness we did: they are delicious! We’ve had them in salads, roasted them and even added them to curries.

Scarlet Globe

Having harvested all of our first crop, we were looking forward to the second, a packet called Bright and Spicy mix that included Amethyst, Scarlet Globe, Sparkler, White Turnip and Zlata.

But rather than create a small rosette of leaves, they sent out long, leggy stems. And below the soil, the root either failed to swell or produced a very small and woody offering. In short, they bolted.

What is bolting?

The dictionary definition says: Bolting in vegetable plants is premature flowering due to environmental and cultivation factors.

So what does that mean?

Plants often have growth stages, where they will grow into a certain form when juvenile and then change form to produce flowers and seed. One non-vegetable example is Foxglove (Digitalis purpurea) where the plant forms a rosette of leaves during the first (juvenile) stage of growth, which usually lasts from late summer to early spring. Then the plant sends up a spike with flowers followed by seed.

Radishes are members of the cabbage family. Like most of that family, they have distinct stages of growth. But like any plant, subject it to any sort of stress and it will try to reproduce, moving on to the mature stage where it produces flowers and seed too early for the production of nice edible swollen roots.

Had we stressed our radishes?

Why have they bolted?

We searched in a selection of books and asked for advice on online forums. We got a confusing range of possible causes:

• irregular watering/lack of watering (one person suggested they need the water to swell them)
• not sowing thinly enough (“they don’t have room to expand”)
• the weather
• sowing too late (one person said that despite what it says on the seed packet, radishes should be sown between early February and March, then not again until September)
• planting too deeply
• the soil was too compact
• the soil was too rich

The variety of suggestions seems to suggest that there’s no simple and direct cause and effect.

We were puzzled because we had just finished picking such a fantastic crop and had, so far as we knew, not treated the second row any differently. The only things we think that might have been different are that these radishes:

• were sown later, when the temperatures were higher and daylight hours longer
• were planted next to the first row and with spring onions on their other side, so potentially did not have enough space.

So, we’re trying again. We’ve cleared the raised bed to give them enough space to grow, and sown another row of Bright and Spicy mix. In this video Andrew shows you’ve what we’ve done.

If you have any thoughts to add about growing radishes or why they might bolt, please let us know.