Radish Growing Guide

Radishes are one of the most nutritious, easiest, and quickest vegetables to grow in your vegetable garden. This hardy, cool-season root vegetable is ready to harvest in as little as four weeks. Radishes can be grown almost year-round as they are planted in cold temperatures of spring and fall. You can plant them in pots, containers, or in-ground beds, making them perfect for your vegetable garden. You can grow these compact plants in small spaces as excellent gap fillers on vegetable beds. They can be a delightful addition to your vegetable garden as the entire radish plant, including the leaves, is edible. When eaten raw, they are incredibly delicious, providing a spicy burst of flavor to salads.

Want to know how to grow this crunchy vegetable from seeds? In this radish growing guide, you'll learn all about growing delicious radishes from planting to harvesting. Let's begin.

About Radishes

Radishes (Raphanus sativus) is an annual cool-season root vegetable and belongs to the Brassicaceae or cabbage family, which includes collards, broccoli, kale, cauliflower, and cabbage. You can plant these vegetables in spring and grow them as fall vegetables. Radishes can be spherical or carrot-shaped with long roots. They come in a rainbow of colors, including green, pink, white, red, yellow, and purple.

Home garden-grown radishes are crisp and juicy with spicy, peppery flavor. They mature quickly within weeks, so you can plant them anywhere in your garden where there is a space or between rows of other crops. Additionally, radishes make great companion plants to help keep pests away from other vegetables.

Types of Radishes

Radishes come in multiple shapes, colors, and sizes. Some popular radish varieties also differ based on their time to harvest. Here are the main types of radishes grown in gardens.

Spring or Summer Radishes (Salad radishes)

These are the famous and extensively grown radish types. Spring radishes are compact and fast-growing. They can be planted in containers or on the ground. Perfect for eating raw, salad radishes are refreshing and crispy.

Spring radish varieties include:

Champion: This variety is small, having bright scarlet, crisp white flesh, and mild flavor.

Icicle: This late spring variety can tolerate mild heat. It has cylindrical white roots and a mild, peppery taste.

Cherry Belle: This classic early spring variety is red and round with mild flavor and crisp white flesh. It matures around 22 days.

German Giant: It has a sweet, mild flavor, red color, and baseball size.

Scarlet Globe: This is an easy-to-grow, mild-flavored radish variety that is vivid red with crisp white flesh.

Winter Radishes

These are hardy radish varieties sown in late summer to early fall for harvesting in winter through spring. Winter radishes are slow-growing and larger in size. Like turnips, they are mostly used in stews and stir-fries and have a mild flavor.

Winter radish varieties include:

Daikon: This radish variety grows well in cooler climates or at the end of the growing season. It is long and white with a snappy taste and matures in around 60 days.

Watermelon: This is an heirloom Daikon radish variety that resembles a watermelon. It has striking white/green skin and a bright pink interior. It has a mild flavor with a hint of pepper.

Spanish Black: This classic variety has a deep black exterior and a pure-white interior that is crisp and pungent. It is turnip-shaped and grows 3-4 inches. It is an excellent choice for gardeners who like spicy radishes.

Oriental Radishes (Japanese radishes)

These radish types are slow growing, forming long tapering roots that are edible both raw and cooked.

Growing Zones and When to Plant Radishes

Radishes grow best in hardiness zones 2 to 11 as annuals. They thrive in cooler conditions and can tolerate light winter frosts. You can plant radishes in spring and late summer or early fall. Sow seeds in early spring when the ground is workable for spring planting.

For fall crops, direct seeds at least 4-6 weeks before the first fall frost. However, stop planting when warm temperatures arrive (65 degrees or higher). The heat will cause radishes to bolt. Since radishes mature quickly, you can sow seeds weekly for a continuous supply of crops.

Where to Plant Radishes

Radishes thrive in full sun but also grow well in partial shade. In hot and dry climates, they prefer full shade in peak summer. Pick a sunny location for radishes that receive at least six hours of sunlight daily with well-drained soil. If planted in the shade or even where nearby vegetables shade them, they will focus all their energy on forming large leaves instead of roots. Since radishes mature quickly, you can plant them in your vegetable garden between slow-growing plants like carrots.

Soil Needs and Preparation

Radishes thrive in well-drained, loamy, or sandy soil with a pH of slightly acidic to neutral (6 to 7). The soil should not be compacted or heavy; otherwise, the plant roots will not grow well. Prepare the soil for planting and improve drainage by adding compost or well-rotted manure in spring or autumn. Avoid adding fresh manure because it usually contains harmful bacteria.

Till the soil to loosen any compaction and remove the stones. If you keep the soil moist, you will soon be rewarded with clusters of peppery roots. According to the University of Minnesota Extension, don't use a fertilizer containing a weed killer, as it can kill your plant.

Spacing and Depth Needs

Sow seeds one to two inches apart and 1/2 inch deep with 6-8 inches between rows. Plant smaller radish varieties shallowly, about 1/4 to 1/2 inch deep, while larger varieties should be planted deeper, about one inch deep. Thin, closely spaced plants to 1-3 inches to encourage healthy root size. Sow seeds in early spring under row covers or hoop houses. After a week of germination, you can thin seedlings, so they end up an inch or 2 cm apart in the row.

How to Plant Radishes

Radishes are quick and easy to grow from seeds directly outdoors in containers or in-ground beds. Sow radish seeds around half an inch deep and 1-2 inches apart and cover them loosely with soil. After sowing, water the seeds thoroughly. Seeds take only 7-10 days to germinate. Radishes can germinate at low temperatures, such as five degrees Celsius or 41 Fahrenheit, as a cool-weather vegetable. Radish plants don't need any support structure.

Sow a new round of seeds every ten days or so to ensure a constant harvest. You can extend the season by planting radishes in containers, bringing them inside, or protecting them with row covers when the weather turns extra cold.

How to Care for Radish Plants

Here are some plant care steps to ensure healthy growth.

Thinning and Weeding Radishes

Thinning is the crucial step in growing radishes. Make sure your radish plants are spaced apart. Thin seedlings 2 to 3 inches once they are about 2 inches tall. Crowded radishes will produce shriveled, small, and inedible roots.

To thin the plant, cut the plant greens at the soil line. You can use the thinnings in the salad. Moreover, weed regularly by hand around the plant so it does not have to compete for moisture and sunlight.

Fertilizing

Before planting, add organic matter such as compost to improve the soil, but avoid high-nitrogen fertilizers. Extra-rich soil will promote foliage growth more than roots. If you are starting with rich soil, there is no need to fertilize radishes later.

Watering

Consistent and even moisture is a key to growing healthy and productive radishes. Radish plants require one inch of water every week. Don't let the soil dry out, as it will lead to concise, pungent roots. Overly dry soil can ruin the taste, cause the plant to bolt, and make radishes bitter. On the other hand, soil that is too wet can cause the roots to split and rot. A drip irrigation system is an excellent way to provide precise and consistent watering to radish plants without over or under-watering. This system provides water directly to plant roots via drip emitters in controlled amounts, preventing evaporation and water wastage. Irrigate radish plants efficiently with a drip system and apply a layer of mulch around the plants to retain soil moisture.

When and How to Harvest Radishes

Radishes are ready to harvest in 20 to 60 days. Salad or spring radishes are best harvested young, as soon as four weeks after germination. In general, harvest radishes when the roots are about 1 inch in diameter and slightly peppery. To harvest radishes, pull up the plant, cut the tops, and thin the roots. The most common mistake gardeners make when growing spring radishes is leaving them inside the ground after their maturity, which causes them to become tough and starchy.

Winter radishes can be kept in the ground for weeks and dug out as needed. You can harvest them in November and store them in the fridge. Winter radishes don't turn woody when mature.

Different radish varieties have different growth times. We recommend checking your plant seed packet to harvest at optimal time. Some types can be pulled three weeks after planting when roots reach 1 inch. Harvest roots when they reach their final size. Delaying harvest in a few days will turn your radishes from crisp and crunchy to woody and overly spicy.

Storing and Using Radishes

Wash the radishes thoroughly and dry them. Put them in produce bags and store them in the refrigerator. Radish edible greens can be stored separately for two to three days. They can be eaten both fresh and cooked. The edible greens of winter varieties can be stored in the fridge for several weeks. However, the bulbs can be stored for 1-2 weeks. They are perfect for consuming fresh or cooked in soups, sandwiches, salads, and other dishes. The peppery roots of radish are commonly used worldwide in appetizers, tea sandwiches, and salads. They can be sauteed, steamed, or roasted. Try different ways of serving them to enjoy their versatility and use the whole plant.

Common Radish Diseases and Care

Radishes are usually trouble-free and are not susceptible to many problems. However, you may get disappointing outcomes if the growing conditions are not ideal. Here are some diseases that can affect radish plants.

Black Rot is a fungus that causes plants to rot, producing yellow triangles on leaves.

Clubroot attacks plants' roots, causing them to become distorted and swollen. They lead to stunted plants.

White Rust is a fungal disease that causes yellow-green spots or chalk-white blisters on leaf surfaces.

Some pests that can be problematic for radishes include:

Slugs and Snails eat seedlings, particularly in damp environments.

Flea Beetles chew leaves and make tiny, round holes in them. However, the damage doesn't hinder the plant's growth.

Cabbage maggot larvae feed on roots and penetrate radishes. This may lead to wilted or stunted plants.

Control and Prevention Tips

Grow radishes under row covers to prevent pest issues.
Mix wood ash into the soil to deter root maggots.
Practice crop rotation by rotating the planting location from year to year.
Maintain ideal growing conditions such as six hours of daily sunlight, well-draining soil, soil pH of around 7, and consistent moisture.
Plant disease-resistant varieties.
Clean and disinfect garden tools before making contact with plants.
Add native plants to your garden to attract beneficial insects.

The Bottom Line

Radishes are the easiest, ravishing, and most nutritious root vegetables to grow in your vegetable garden if they have well-drained soil and mild cold temperatures. They are flexible, fast, and super yummy. Their rapid growth and ease of cultivation make them the perfect vegetable to use when teaching gardening to children. Grow them in raised garden beds, pots, or in-ground beds and enjoy a generous harvest within weeks. So, grab your garden tools and start planting this versatile vegetable.

If you like to grow some other cool-season vegetables in your garden, you might find the following growing guides useful: