Round or long roots, scarlet red tipped with white, ready to pull four to six weeks after the seed goes in: radish (Raphanus sativus) is the quickest crop in the vegetable patch and one of the easiest things to sow. Water regularly and harvest young, before the root splits and turns hollow and fibrous.
Radish at a glance
Name
Raphanus sativus
Family
Brassicaceae
Type
annual
Height
7 to 12 inches (15 to 30 cm) depending on variety
Exposure
full sun, part sun
Soil
ordinary but light
Harvest
4 to 6 weeks after sowing
From seed to harvest, here is everything you need to know to grow your radishes well. Early planting or forcing radishes gives a harvest in 3 to 4 weeks.
Sowing radish can take place all year round, with a preference for the end of winter, in late winter, and summer from early summer to early autumn
Radish are one of the easiest plants to sow. Spread the seeds directly where they are to grow, cover with a little dirt or soil mix, and water regularly to quickly harvest beautiful fresh radishes.
Sowing forced radish
Forced sowings go under a cold frame or tunnel
Sowing in late winter under a cold frame or a tunnel greenhouse.
The first radishes are called “forced” because they are ready earlier than they would have been naturally.
Sowing radishes every month
From late spring until the end of the summer, even ’til early fall, weather permitting.
Sow the seeds directly where they are to grow, no need for cold frames.
Sowing summer and fall radish
Sowing during the whole summer
Sow directly in the plot, again without shelter.
Winter sowing
Sow directly in the ground from Early summer to late autumn depending on the climate.
Sow in rows with a 8 to 12 inch (20 to 30 cm) spacing between rows.
Techniques for sowing radish
The manner in which radish seeds are sown is the same throughout the year.
Seed the entire bed in a matter of seconds with broadcast sowing.
If you prefer rows, sow with 8 to 12 inches (20 to 30 cm) between rows.
Cover with a thin layer of soil mix (around 3/8ths of an inch, or 1 cm)
Lightly compact the soil
Once seeds have sprouted, thin them out. This means to removing the weakest sprouts and only keeping the most vigorous ones, spaced every 1.5 to 2 inches (4 to 5 cm).
Keep the ground clear of weeds by removing them as they appear.
Lightly break the surface crust regularly with a small hoe to let water trickle down to the roots.
Of course, it is also great to sow your radishes in a garden box, with soil mix and regular watering.
Caring for radish
Once sown, radish asks only for regular watering
Radish is very easy to care for. Once sown, the only care it needs is regular watering.
Water frequently in summer to ensure that the soil remains cool.
Lightly break the surface with a small hoe to let water trickle down.
Remove weeds as they appear.
Avoid fresh manure or nitrogen-rich feeds on the bed, which push out lush leaves while the root below stays thin and disappointing.
Tiny shotholes peppering the leaves are flea beetles; a fine mesh or fleece laid over the row from sowing keeps them off.
In hot weather give the row a little afternoon shade, since heat makes radish bolt to flower and the root stops swelling.
Radish belongs to the Brassicaceae, so treat it as a cabbage in your rotation plan and keep it off ground that has just grown turnip, swede or kale.
Scatter a few radish seeds along a row of carrot or parsnip: they sprout fast and mark the line before the slower seed appears.
Flea beetles will go for radish leaves first, which makes a nearby row a useful decoy for young cabbages.
Harvesting radish
Harvesting radish is easy and usually takes place 4 to 6 weeks after sowing.
It is thus a pretty quick crop, and best is to harvest them at the right moment to savor the best taste.
Pull them young, before the root goes hollow
If you delay, it splits inside and becomes hollow and fibrous (less appetizing and slightly more difficult to digest).
Once the first radishes are well-formed, it is best to harvest them regularly.
Do not let them get too big, it is better to harvest them too early than too late.
Once you’ve harvested the root, use the leaves to make a delicious radish leaf soup!
Which radish to sow, and when
Radishes fall into two camps: those forced early under cover, and those sown again and again through the growing season. This table sets the named varieties side by side so you can pick on root shape, sowing slot and reliability.
Which radish to sow, and when
Variety
Root and character
When to sow
‘Atten Dage’ (18-day radish)
Long-standing favourite, very early; sharper than modern rivals
Late winter, under cover
‘Gaudry’
Round root, half scarlet red and half pearly white
Late winter, under cover
‘Orléans’
Long, cylindrical roots
All year round
‘Wurzburger’
Very good heat resistance
Summer
‘National’
Round, bright red with a white tip; stays solid when large
Late spring to late summer
‘French Breakfast’
Medium length, grows anywhere, ideal for beginners
Late spring to late summer
‘5 weeks’
Long pointed roots
Mid-spring to early autumn
Mixing a forcing variety with one or two of the monthly types keeps roots coming from late winter right through to autumn.
Species and varieties of pink radish
This list distinguishes between radishes that can be forced and those to sow month after month.
Radish varieties for forcing
‘Atten Dage‘ (also called 18-day radish) – long-time favorite, outsold today by more modern varieties that are also early planting like ‘Fluo‘, ‘Bamba‘, ‘Kiva‘, ‘Sarda‘ or ‘Flamino‘ – their taste is not as sharp and spicy.
‘Gaudry‘ – a famous reference, round root, half scarlet red and half pearly white.
Varieties of radish for sowing every month
Roots may be round or long and cylindrical
‘Round Scarlet‘ – round root, delicious.
‘Orléans‘ – long roots, cylindrical, can be sown all year round.
‘Wurzburger‘ – sown in the summer, very good heat resistance.
‘Sézanne‘ – spherical bright pink roots with a white collar.
‘National‘ – round roots, bright red with a white tip, doesn’t hollow out as it grows big.
‘Cerise‘ – deep roots, bright red, doesn’t hollow out as it grows big.
‘Easter Pink‘ – soft and tasty roots.
‘Fakir‘ – round, firm flesh, delicate taste.
‘French Breakfast‘ – medium length, grows anywhere, perfect for beginners!
‘5 weeks‘ – long pointed roots, to sow from mid-spring to early autumn.
Other species and types of radish
Radish is a rather all-encompassing term. Spring radish, typically called pink radish, is a group of radish that likely derives from a wild ancestor called Raphanus landra. Black or winter radish is more likely to have been domesticated from another: Raphanus maritimus.
Apart from these, other plants also go by the name radish: horseradish, daikon radish…
Smart tip about radish
To have crunchy radishes all season long, it’s a good idea to sow new seeds every once and a while.
Sow every 2 to 3 weeks to guarantee that you always have ready-to-eat radish at hand.
