Radishes grow best in the spring or late summer. They do not like hot weather. For quality yields, radishes should be grown rapidly with plenty of moisture. Approximately 80 seeds/gram.
Hints:

Sow seed 1 cm apart and 1 cm deep in rows 30 cm apart.

Thin to 2 to 4 cm apart.

Sow several times at weekly intervals until early summer for a contiuous fresh supply.

Try sowing with other vegetables to help mark row.

Sparkler [White Tip] - 25 days. Roots almost round, skin bright scarlet red with white tip. Flesh clear white, tender and very crisp. Tops medium. One of the best market varieties. Very popular with the home gardener.