Wikijunior:The Little Gardener/Radishes
With your Radish seeds and all of your tools ready, it is time to plant and grow some Radishes!
Step 1 
First, you have to separate and count the seeds that you want to plant. Radish seeds are small, but you should be able to separate them with your hands.
Step 2 
Then, either use your hands or a small cup to put your soil into the pot. This can be messy! You might want to do this outside, or over your sink because the soil can clump together and spill. Fill the pot with soil until it is close to the top. Gently push on the soil so it is a little firm, but do not too push too hard.
Step 3 
Dig a small hole, either with your finger or with one of your tools. If you are going to use a tool, the transplanter works well for digging holes. Measure the hole so that it is 1/4" from the top of the soil.
Step 4 
Drop 1 seed in the hole! Then, take a pinch of soil and fill the hole. Again, gently press down on the soil.
Step 5 
Pour a litle water into your pot.
What is next? 
Make sure you water the seed everyday! If you are unsure about watering the seed, remember to use the "lollipop stick test" to check your soil. After the sprout comes out of the soil, which takes about 7-14 days, you have to make sure that it gets good sunlight.
If you are growing it indoors, you have to move it to a larger pot so that the roots can spread out. If you are going to move the seed outside, make sure that each sprout is placed at least 2" apart from eachother so that plants have plenty of room to grow when they get bigger.
How much light, and when can I plant it outside? 
Radishes love to get just a little bit of sunlight, so you need to make sure that they get 5 hours a day of sunlight. If you are trying to grow your Radishes indoors, they will need to get a more light than it would if it were outside in direct sunlight, which would be about 7 hours with the grow light on.
Most plants like to planted during the Spring season, or the time of the year when the days begin to get longer and the temperature gets warmer. Spring happens at different times of the year for different parts of the world. In Australia, Spring begins in the beginning of September, and in the United States, Spring begins at the end of March. You do not want to transfer your seeds outside if it is still cold out at night. Frost will stop your seedling from growing.