Growing radishes, 40 days from seed to table

Radishes are the best vegetable choice for the first time gardener or someone who wants to use a window flower box for vegetables. Requiring only 6 inches of soil to grow, radish seeds germinate in four to six days and are ready for harvest in four to six weeks.

How to Plant Radish Seeds

Plant radish seeds in full sun after danger of frost. Push the seeds 1/2 inch into the soil and space the seeds 2 inches apart. If planting more than one row, space the rows 6 inches apart. Another planting option is to toss the radish seeds in the garden, toss about 1/2 inch of soil on top of the seeds, and then when the radishes sprout, thin to 2 inches apart by pulling out weaker sprouts. 

Caring for Radish Plants

Keep the soil moist, which may mean watering the radish plants more than once a week if there is no rain. If planting radish seeds in a window flower box, light watering on a daily basis may be needed since the sides of the box expose the soil to the heat of the sun, which dries the soil.

The leaves of the radish plant are about 2 inches wide and mostly upright. The leaves will droop and shrivel where there is not enough moisture. Watering the radishes will rehydrate the plant and perk up the leaves.

No fertilizer is needed; however, compost or leaf mold can be worked into the soil before planting the seeds if desired.


About four weeks after the radish sprouts show, spread the leaves of the plant and look for the “shoulders” of the radish. The shoulders are the top of the radish and may emerge slightly from the soil, indicating time to harvest. If the radishes are too crowded underground, the radish may mature above ground with its taproot getting nourishment from the soil.

If the shoulders of the radish do not show, push your finger into the soil next to the leafy top and feel for a radish. A radish ready for harvest will be 1/2 to 1 1/2 inches in diameter. Still in doubt as to whether to pull the radish out because you are not sure of its size? Go ahead and pull it out. If the radish is too small, replant it.

The Best Thing about Growing Radishes

You would think that eating the radish is the best thing about growing radishes but this gardener believes the best part is that you can plant more seed after the first harvest. Being able to replant radishes is particularly beneficial if you are planting radishes in a container, like a window flower box.