Radishes (Raphanus sativus) are an edible root vegetable that is part of the Brassicaceae (mustard or cabbage) family. Believed to have originated in China, today radishes are enjoyed around the world.
As a fast-growing crop, it’s easy to grow radishes. They’re ideal for teaching kids how to grow and nurture vegetables or as your first attempt at growing veg.
Radishes are used in a variety of dishes or eaten raw as they are low in calories, a good source of vitamin C and contain small amounts of magnesium, Vitamin B, folic acid and more.
There are also many health benefits to radishes. They can be used to relieve stomach ache, to facilitate digestion and regulate blood pressure.
Interesting radish facts!
First cultivated in China, radish crops spread through the Northern Hemisphere and into Europe in the 1500s.
Because they grow rapidly, radish plants are ideal for children’s gardens.
As a member of the Brassicaceae family; its cousins are broccoli, cabbage, cauliflower, and turnip.
Biggest ever recorded radish (root) was nearly a metre in length and about 45 Kg in weight.
In Mexico, December 23th is the annual Night of the radishes festival.
Ancient Egyptians used radish oil in their diet before olive oil was discovered.
To grow radishes successfully, you’ll want to plant them in a sunny spot. Too much shade and they’ll waste their energy producing larger leaves.
The soil should be rich in organic matter but loose. If you have clay soil, mix in some sand to loosen it and improve drainage. It’s worth adding a few centimetres of aged compost or all-purpose fertilizer to ensure the soil is rich in nutrients.
Another element to consider with soil is crop rotation. Ideally, you’d work on a three-year crop rotation plan. This means you plant radishes every third year in the same spot. Doing so will prevent diseases.
Hundreds of varieties of radishes are available and many grow all year-round. They vary in size, taste, and colour but share nutritional values.
The RHS recommends growing the following varieties of radishes:
‘Ping Pong’ AGM
Produces a very uniform crop of solid, round, white roots that are crunchy, juicy and have a mild flavour.
‘French Breakfast 3’ AGM
A long, cylindrical radish, red with a white tip.
A small-leaved variety with round, small, bright red roots.
Medium-sized roots coloured pink with a white base. Reliable, easy and fast to mature.
It’s best to plant radish seeds directly into the soil so that the roots aren’t disturbed. Ideally, you’d plant a small amount, often. For a summer harvest, start planting from March to mid-August. If you’re after a winter crop, sow in July or August.
Sow seeds around 3 cm into the ground, leaving about 3 cm between seeds. After planting, cover lightly with soil and water. Continue watering on a weekly basis if conditions are dry.
If planting in rows, you’ll want around 30 cm between them. You can plant another row every 10 days or so to extend the harvest.
How to nurture radishes
You shouldn’t need to thin plants out as you’ve sown at a sensible distance from the start. If plants look like they are growing too close, then thin them out quickly.
As rapid growing veg, radishes need moisture and so you’ll want to keep watering. This will keep the roots fleshy and tasty while preventing splitting. If you’re planting in the middle of summer, pay extra attention to how moist the soil is.
Radishes as quick to mature, so you can plant them between rows of slower growing veg such as peas and potatoes. You can even use them as row markers for parsnip and onion or any slow germination crop.
The radishes will germinate quickly establishing where the other crops are planted and can be harvested long before the main crop starts to develop.
One of the benefits of growing radishes is that they’re ready to harvest in as little as 3 to 5 weeks. It’s why kids like to grow radishes!
For most varieties, harvest when roots are around 3 or 4 cm in diameter at the soil surface. Start by pulling one out of the ground. If it looks and tastes good, then harvest the rest!
You don’t want to leave radishes in the ground for too long after they’ve matured as their condition will deteriorate quickly.
How to store fresh radishes
After harvesting, remove the leafy green tops and place in sealed plastic bags. Keep them unwashed in the fridge ready for use. They’ll last between one and two weeks and are excellent braised or sautéed in olive oil.
With the radishes, again place unwashed in sealed plastic bags with a slightly damp paper towel at the bottom. Place each bag in the crisper drawer of the fridge as this will be cool, moist and dark. You should find they last a few weeks.
You can freeze radishes, but you should blanch them first to maintain taste and texture.
Common pests and problems
Part of growing any vegetable involves managing pests and disease. Here are the most common issues to look for when growing radishes.
Slugs and snails
Feeding on young seedlings, slugs and snails are easy to identify as you’ll notice slime trail on the soil around your crop, as well as on the leaves. Luckily, it’s easy to stop slugs and snails in their tracks by using sawdust, eggshell barriers or beer traps.
Seedlings are particularly susceptible to flea beetle. You’ll see small holes on leaves and the damaged areas will turn brown. To deter beetles, grow plants under horticultural fleece and keep the soil moist and topped up with nitrogen-rich fertiliser. These will help the crop outgrow the pest.
Plants may die from club root. You’ll see roots become swollen and distorted. Leaves will become pale and yellow and wilt easily. To avoid club root you need to improve drainage and add lime to make the soil more alkaline. Do not grow in affected soil.
Brassica downy mildew
A common disease of brassicas, as they are not planted for that long. You’ll notice yellow leaves with white, fuzzy patches on the undersides. Also, roots may turn brown.
To solve, you’ll need to remove infected plants quickly and practice crop rotation. Next year, you’ll want to plant them in a different area.