Radishes are known as one of the easiest vegetables to grow in British gardens, as they grow quickly with very little effort. However, in summer, they need more attention as hot temperatures can cause them to bolt, which is when certain vegetables start to produce flowers very quickly.
This might sound appealing, but it is actually a sign that the plant is under too much stress and has shifted its energy from growing to producing seeds. As a result, you will not get a fruitful harvest from your radishes as it will become small, tough, and bitter to eat since it is now focusing all its energy on spreading its seeds.
Sandra, a gardener and cofounder of The Quest for Veg has shared she loves growing radishes but has had her entire harvest fail due to bolting.
She said: “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.”
After doing some research, Sandra discovered that her radishes likely failed because they were overcrowded, as too much was growing around them.
She added: “The only things we think that might have been different are that these radishes…were planted next to the first row and with spring onions on their other side, so potentially did not have enough space.”
Bolting is triggered when the plant cannot get enough nutrients or water in hot weather so it begins to produce seeds before it dies as it will completely stop growing.
It is really easy to accidentally plant too many radishes in the same area, and people vastly underestimate how much they expand while they are growing.
Since they are such a simple crop to grow it tends to be best to get rid of the bolting radishes and simply make sure there is more space around your next batch of seeds.
However, summer tends to be the worst time to grow radishes as the high temperatures and long daylight hours makes it more likely for cool seasoned vegetables to bolt.
It is possible to grow radishes in summer as long as they have enough room to grow, but if you want to guarantee to get a harvest then you might want to wait and plant them later.
Radishes prefer cool temperature below 20C and lots of moisture, so waiting until late August to early September will guarantee you get lots of big colourful radishes to put in salads or curries.