Step-by-step: radishes

Learn how to grow and make the most of these reliable roots in the kitchen garden and spice up summer salads!

Scour the shelves of your local supermarket for salad and you might be led to believe that the red, round-shaped radish is the only type on offer. But, grow your own, and you can experiment with yellow, purple and even white varieties of this versatile salad crop. Unfortunately, it’s all too easy to by-pass this easy-to- grow brassica in favour of tackling more ambitious vegetables such as broccoli, aubergines and cauliflowers and miss out on that distinct peppery, mustard-like taste and crisp crunch. Quick to mature, radishes can also be used as row markers for slower-germinating crops and can be sown successionally to keep harvests coming throughout summer. The best time to get them in the ground or in pots is from February to August.

1) Most varieties of radish can be grown in pots. Choose a container that is 15cm deep as this will give the roots space to spread out and fill with potting compost just below the surface of the container. Space seeds 2.5cm apart and sow at a depth of 1cm. Sprinkle with a fine layer of soil and firm.

2) Radishes need a good amount of sunlight to grow well so place your container in a spot that gets at least six hours a day. Keep your pot well-watered and seedlings should appear within five to seven days. By sowing seeds 2.5cm apart, there should be no need for thinning. However, if your seeds start to get a bit crowded, thin to 5cm apart as soon as possible.

3) If sowing outside, it’s a good idea to choose your spot and prepare the ground beforehand. Radishes prefer to be grown in rich, moist and free-draining soil and in full sun but will tolerate some shade throughout the day. Use a hand trowel to remove weeds and large stones that will obstruct the growth of emerging seedlings.

4) Radishes can be sown straight in the ground from March to mid-August. When ready to sow, make holes 1cm deep, spaced 2.5cm apart, and individually plant one seed per drill. Space rows 15cm apart as this will stop the seeds from having to compete for vital resources.

5) Labelling pots and growing spots is useful as these brassicas are available in both summer and winter cultivators. Winter radishes, such as mooli, are planted later in the season, from July to August, and harvested from August to November. Mooli also need to be spaced 23cm apart, later thinned to 15cm apart, and can be left in the ground much longer, even over winter.

6) Continue regular watering to ensure quick growth, tender roots and to prevent crops from splitting and running to seed. Radishes planted in July and August are at a bigger risk due to the hot and drier weather conditions. However, do not over-water them as this can encourage leaf growth and stunt root development.

7) Sow seeds little and often, usually at two-week intervals, to ensure you have a continuous supply throughout the summer harvesting period. However, make sure not to sow seeds all at once but to reserve and portion them out for use during the busy growing months.

8) Radishes are great to grow in the garden because they’re quick to mature and are therefore ideal to grow as row markers between slower-germinating vegetables. Plant either side of crops such as parsnips, carrots and onions to see exactly where they’ve been sown. Experiment with varieties such as ‘French Breakfast’, ‘Cherry Belle’ and ‘Fire and Ice’.

9) Harvest four to eight weeks after sowing. Picking these roots young preserves that peppery, mustard-like taste and crisp bite. Leaving them in the ground for longer will turn them woody, tough and inedible. Slice raw and toss into salads or top on rye bread for an extra kick. You can also stir-fry, pickle and even roast.

Be prepared for pests
This catch crop might be small but like all fruits and vegetables, it’s still at risk from pests and diseases. Flea beetles, tiny black bugs that feed on the leaves of members of the brassica family, will swoop in fast and wipe- out your radishes. Tell-tale signs of an infestation include a sprinkling of holes and brown patches on seedlings, as these are most likely to be affected.

The best way to protect radishes from flea beetles is to grow them under horticultural fleece to stop the bugs from getting to them. Continued watering and feeding with a nitrogen- rich fertiliser will also give your crops a real boost that will help them to fight off the pest.

Slugs and snails will also feed on radishes, especially during the spring and summer months when an explosion of these slimy creatures seems to occur. Keep slugs and snails away using chemical-free, environmentally-friendly pest-control methods including beer traps, sawdust and eggshells.

The final problem to look out for is brassica downy mildew – yellow leaves and furry, white patches are closely followed by brown roots. This disease is a lot harder to control but digging up infected plants and making sure not to plant brassicas in places where previous brassicas have been planted, but rather sticking to a rotational system, should help to keep this under control. The final problem to look out for is brassica downy mildew – yellow leaves and furry, white patches are closely followed by brown roots. This disease is a lot harder to control but digging up infected plants and making sure not to plant brassicas in places where previous brassicas have been planted, but rather sticking to a rotational system, should help to keep this under control.

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