A Good Start
Soil conditions, moisture and optimum temperature are extremely important in growing good radishes. Radishes are seedlings for such a short time that this is a critical stage in the life of the plant. You’ll have best results if you pay careful attention to these issues and provide your radish seedlings with what they need.
Seedling to Radish
Radishes are probably the quickest-growing of all vegetable crops. Some varieties mature in about three weeks. That means your radishes can really only qualify as seedlings for about seven days. After that, they are small but developing plants. Varieties with longer maturity dates may remain seedlings for two weeks.
Radishes prefer friable, moisture retentive soil. A sandy loam is ideal. Add humus in the form of well-aged manure, compost or leaf mold to promote these conditions. Soil depth is also important for this root vegetable. Remember the feeder roots may be several inches longer than the depth of the radish seedling and plan accordingly.
With maturity rates of three weeks in some cases, there’s no time to make up for nutritional lacks. Radishes need all the basics in the soil before you plant. Phosphorus is particularly important. Bone meal and rock phosphate are good sources. Be careful not to add too much nitrogen; your radish seedlings may become leafy but not develop roots.
Too much water can make your radish seeds and seedlings rot in the ground. Too little, however, will stunt or even kill your tiny plants. You want the soil to be moist, but not soggy. Check your radishes at least once a day and water if necessary.
Radish seedlings grown in less than optimum conditions won’t do well. Here are potential problems:
- Light – radish seedlings need full sun for best growth.
- Soil Temperature – optimum temperature for germination is 45 to 85 °F (7 to 29°C).
- Air Temperature – optimum temperature is 50 to 65 °F (10 to 18°C).
Seedlings as Food
Radish seedlings can actually be used as food long before they become plants. You can clip them at ground level with fine sharp scissors as soon as the leaves have some green. You can also germinate them in a glass jar and eat the entire seedling.