Growing guide
How to grow radishes in Ireland
Radishes are best planned in small batches rather than long rows. A modest sowing followed by another a fortnight later is more useful than roots that all become woody before you eat them. Summer salad types and larger winter radishes need different spacing and sowing dates. Quick growth is the attraction, but timely watering and picking still matter.
On this page
At a glance
- Start with
- Seed of a summer salad or winter variety
- Best position
- A fine seedbed where frequent watering and picking are practical
When and where to start
Direct sowing. Sow summer radishes from March to August, and winter types in July or August. Teagasc gives roughly four to eight weeks for summer roots and eight to ten for winter ones. Warmth and conditions affect progress; these are not guaranteed harvest dates.
Planting and spacing
Aim for rows 15 cm apart with summer plants about 3 cm apart. Sow thinly and thin crowded seedlings so neighbouring roots have space.
Winter radishes need about 15 × 15 cm. They are not summer types kept a little longer: use the correct seed and wider layout.
Follow the packet’s sowing-depth instructions. Label each small batch, cover evenly, firm gently and use a fine watering rose when needed.
Routine care
Keep the summer crop well watered during dry spells so it grows without repeated checks. Remove weeds while seedlings are small rather than disturbing mature roots later.
Check developing roots often. A quick crop can move from crisp to woody quickly too; leaving the oldest batch untouched defeats the point of repeat sowing.
What to watch for
Flea beetles, slugs and cabbage root fly are listed pests. Look at the roots as well as leaf holes when checking a struggling patch.
Woodiness is a common practical disappointment when summer roots are left too long. Small sowings every two weeks make it easier to harvest at the right stage. Disease names in a guide are not enough to diagnose every damaged root.
Harvest and storage
Begin lifting summer radishes around 2 cm diameter for the types described by Teagasc. Pick what you need, but do not leave the remaining row indefinitely.
Winter roots are larger and can be eaten raw or cooked like turnip or swede. Use harvested roots promptly; small batches are easier to enjoy while crisp.
Common questions
Are winter radishes just late summer radishes?
No. They are larger types with a different sowing window and wider final spacing.
Why avoid one big sowing?
Summer roots can turn woody before a large batch is used. Short successive rows make timely picking more realistic.
Do all radishes grow at the same speed?
No. Summer and winter types differ, and conditions influence both. Check size and quality, not only elapsed weeks.