Cultivating delicious, red radishes is easy. Here is everything you need to know about sowing and harvesting your own!
Radishes are a popular summer vegetable – and no surprise. Their crunchy texture and spice works wonders in salads, on bread and in dip. Radishes are also packed with vitamins, minerals and mustard oils, making them extremely healthy.
The humble radish (Raphanus sativus var. sativus) belongs to the genus Raphanus in the crucifer family (Brassicaceae). Originally from Asia, these delicious tubers have been a staple of European cuisine since the 16th century.
There are plenty of varieties to choose from, each with a different cultivation time, colour, shape and taste. All radishes, however, are easy to grow in the garden or on a balcony. As they grow so fast, because they grow so fast – radishes are normally ready to harvest after about 4 weeks – you can easily rotate them with other crops.
Tip: Avoid planting radish next to crucifers, like horseradish and cabbage, as this can lead to various lant diseases. Otherwise, radishes make perfect companions crops, especially with peas, beans, lettuce and spinach.
How to plant radishes: location and soil
For a successful harvest, it is important to choose the right location and right soil for your radishes. These red tubers normally prefer a sunny to semi-shady location. However, if you plan to sow your radishes in mid-summer, opt for partial shade, otherwise your radish’s roots may spread too much.
Radishes grow well in all normal garden soils, but be sure the soil is loose, humus-rich and well-watered. Importantly, before planting your crop, avoid over-fertilising the soil, especially with mineral fertiliser. If the soil is too nutrient-rich, your radishes will become susceptible to disease and pests. They will grow too many leaves, and too few tubers.
Tip: If you have sandy soil, which stores nutrients poorly, it can be helpful to fertilise radishes organically with our natural Plantura Tomato Food.
Loosen up the soil in your vegetable bed if it is heavy or dense, so that the tubers can move easily grow in the earth. And if you are growing your radishes in a pot, reach for peat-free potting soil, such as our Plantura Organic Tomato & Vegetable Compost.
At some point, you may notice your radish forming flowers, and growing tightly upwards. This is called shooting. If you want to harvest radish seeds, this is great. If you want to eat your tubers, it is not. Radish shooting removes water and energy from the tubers, making them dry and inedible.
- Perfect for tomatoes & other vegetables such as chillies, courgettes & more
- For strong & healthy plant growth as well as an abundant vegetable harvest
- Peat-free & organic soil: CO2-saving composition
Sowing radish seeds is easy and you can do it throughout the growing season. Read on to find out how!
When to sow radishes?
Radishes are one of the earliest vegetable crops of the year. You can sow radishes in February, but it is better to wait until March, when there is less frost. Even then, late frosts can be a problem, so keep a fleece to hand. You can sow radishes every week until September, which will ensure you have a crop well into October.
Note: Not all radish varieties grow well at all times of the year. In warm temperatures, some varieties will shoot without forming any tubers at all. So be sure to pick the right radish variety for the right season!
How to sow radishes?
To sow radish seeds, you will first need to make a shallow furrow in the earth. Leave a 10 to 15cm gap between each furrow and use a stick or the back of a garden rake to ensure each furrow is straight. Now, sow your radish seeds 1cm deep and 3 to 4cm apart in the furrows. Cover the seeds with soil, press down and water. At around 15°C, and with enough water, the seeds should germinate within a few days.
Tip: Do not sow your radish seeds too deep, or they will form elongated, woody tubers!
Another, easier method is to scatter your radish seeds across unprepared soil. However, this can cause dense growth. Shoots that are too close together will need to be pulled-up and replanted, so that each plant has enough space to develop healthy tubers.
Radishes are some of the fastest growing garden plants. As such, they are often used as “marker seeds”. Plant some radishes to the left and right of slow-germinating plants, like carrots, as a reminder that your slow germinators are still growing!
Planting radishes in a pot
Growing radishes on a balcony or terrace is easy. Just ensure that your plant pot is large enough to accommodate 10 to 15cm row spacing, and has a drainage hole at the bottom.
Fill the container with potting soil, to a depth of about 15cm, and sow the radish seeds as you would in a garden.
- Sow from early March to early September
- Rake through your garden bed and make holes for the seeds
- For early sowing, protect the seeds or seedlings from late frost using a garden fleece or plastic cover
- Sow to a depth of 1cm
- Keep a 3-4cm gap between each seed
- Keep a 15cm distance between rows of seeds
- Cover the seeds with a thin layer of soil and press lightly
- Water daily
Radish plant care
For large, crunchy radishes, you will need to water your plants regularly for 4 to 8 weeks. Irregular watering can cause underdeveloped or burst tubers. Be sure to use a watering can rose to prevent freshly sown seeds from washing away!
Want to know even more about the humble radish? Have a read of our article!