The radish is one of the easiest, quickest-growing crops you can grow in your garden. Whether you choose to grow them in a container or in a traditional garden bed, you can expect a harvest about one month after you sow the seeds -- this is as close to instant gratification as gardening gets!
There are two general types of radishes: spring radishes and winter radishes. Spring radishes are the ones that most of us are accustomed to -- small and spicy, crispy and quick growing. These are eaten as soon as possible after harvest. Winter radishes, however, are less common but no less deserving of a spot in your garden. They take longer to mature (closer to two months instead of the one month for spring radishes) and can be stored the way you'd store carrots or other root crops, in a cool, dark spot in damp sand or sawdust.
Where to Grow Radishes
Radishes grow well in all climate zones, though they should be grown as a winter crop in areas that have very hot summers and mild winters. They appreciate full sun, but will also grow well in part shade, and actually prefer a bit of shade during the heat of summer, when excessive heat can cause them to turn woody and bolt.
You can grow radishes in a traditional garden bed (one common practice is to sow radishes and carrots together; the radishes loosen the soil for the carrots, and by the time the carrots need the space, the radishes are ready to harvest!) or in a container. If you decide to grow radishes in containers, just make sure that the pot is filled with good quality organic potting mix and that the container itself is at least six inches deep.
Sow seeds for spring radishes directly in the garden three to five weeks before your last spring frost date, and keep planting every two weeks until one month after your first fall frost to ensure a continuous harvest. Seeds should be planted 1/2 inch deep and 1 to 2 inches apart. If you plant at this spacing, you won't have to worry about thinning.
To make the most of your gardening space, consider sowing radish seeds in areas where longer-growing crops, such as broccoli or Brussels sprouts, are planted. By the time the larger plants are starting to fill in, your radishes will be ready to harvest.
How to Grow Organic Radishes
Radishes require two things to remain healthy and tasty: cool temperatures and plenty of water. Radishes need more water than most other root crops. If they don't get enough water, the roots turn woody and tough, so make sure that they get at least one inch of water per week. Hot weather causes most radishes to turn extremely spicy and/or bitter, and will cause most varieties to bolt almost overnight. To counteract hot weather, mulch your radishes well and consider growing them under a shade cloth.
If they're grown in good soil, radishes don't require any fertilization.
Radish Pests and Problems
Radishes are bothered by very few pests, though the most common one is the flea beetle,, which can riddle the leaves with dozens of tiny holes in no time. A bad infestation may result in too much damage to the leaves to produce a good-sized root. To prevent flea beetle problems, grow your radishes under a floating row cover. You can also use yellow sticky traps to catch the flea beetles.
Recommended Radish Varieties
- 'Cherry Belle'
- 'Easter Egg'
- 'White Icicle'
- 'French Breakfast'
- 'Black Round Spanish'
- 'Misato Rose'