By National Gardening Association Editors, June 23, 2008
- Plant short-season or spring varieties in spring or fall, depending on local temperatures. Ideal growing temperature is 60° F to 65° F. Cooler or warmer weather results in harsher-tasting radishes. Plants will mature in 18 to 45 days, depending on variety.
- Plant winter types in the summer or fall, depending on the variety; they mature in 45 to 70 days.
- Spring radishes can be planted right next to rows of larger, slower crops - no need to create a separate radish bed.
- Sow radishes directly in the garden. Plant spring varieties 1 inch apart, 1/2 inch deep.
- To get larger spring radishes, plant seeds 1 1/2 inches deep, 1 1/2 inches apart, in rows 24 inches apart.
- Plant winter radish varieties 1 to 3 inches apart.
- When young radishes are 1 inch tall, thin to 2 to 3 inches apart.
- Provide even watering. Heat and too little or uneven watering can result in tough, pithy, very hot radishes.
- See our article Summer's Bad Guys by Charlie Nardozzi for controls of common radish pests such as root maggots.
- Pick spring varieties as soon as they reach the size you prefer.
- Before they become tough and pithy, pull all the radishes, trim off the tops, and store in plastic bags in the refrigerator.
- Winter varieties will keep adequately in the ground for a few weeks after maturity, in cool weather. Store these radishes through the winter as you would carrots or beets, in sawdust or peat moss.