Learning how to plant radish from seed can give you a head start on the growing season and allow you to enjoy this tasty vegetable year-round.
However, while radishes are easy to grow, slight temperature, water, and even time changes can result in unusually spicy bulbs or no bulbs at all.
In this article, we will look at a simple method to grow radishes at home from seeds and some tips on adjusting this process based on your area.
With that in mind, let’s get started with the first step.
1. Choose The Right Variety
Radishes are cool-weather vegetables whose taste and texture are affected by high temperatures.
As a result, choosing the variety of radishes to grow is essential based on your local climate and the time of year you intend to produce it.
For example, I usually grow Cherry Belle radishes successfully year-round. However, the temperature for several months last year averaged around 90°F resulting in several failed crops.
That said, it’s best to grow radishes in spring, and fall, so long as there isn’t a risk of freezing. You can even grow winter varieties, which can remain in the soil for several weeks after they are ready.
2. Prepare The Planting Area
Radishes grow best in moist, well-drained soil that is rich in well-rotted organic material.
You can achieve this by adding an inch or two of compost to the soil’s surface, or growing the radishes in a quality potting mix. This helps to promote root development and the overall growth of the plant.
Radishes prefer at least 6 hours of direct sunlight daily but can grow in shaded areas, especially during the heat of the summer.
You must remove any weeds or other volunteer plants that may cast a strong shadow on your radishes or compete for resources.
3. Sow Seeds In A Seedling Tray
Radish seeds are tiny and look quite similar to those of cabbages, kale, and other members of the Brassicaceae family, to which they all belong.
You can sow radishes directly in the garden, provided your soil is well-prepared. However, I like to use the multi-sow technique and plant radish seeds in trays. To do so:
- Fill a seedling tray with moist potting mix and tap gently on the table to allow the mixture to settle.
- Next, remove the excess potting mix and make a slight impression in the middle of each cell, about ¼ inch deep.
- Sow 4 to 6 seeds in each hole and cover them with a thin layer of soil.
- Water them gently and place in a warm dark spot until seedlings emerge.
4. Thin Radish Seedlings
Radish seeds usually germinate in about 4 days but can be delayed up to two weeks in colder climates.
Monitor the seedling tray and remove it from the shaded location at the first sign of germination and place them in a cool, well-lit area.
Water seedlings when necessary, and ensure the soil does not dry out.
Thin the seedlings down to 3 or 4 per cell within the first few days of germination. If you fail to do this, you may end up with leggy radish seedlings.
Transplant your seedling to the garden bed or container within 7 days after germination.
Note: You do not have the time to harden off these seedlings, so ensure they receive enough light from the start.
5. Water And Fertilize
Radishes need at least one inch of water per week, but this will vary based on the temperature and actual moisture in the soil.
As a result, you will need to monitor the soil, especially during dry spells, watering more often if the ground feels dry.
Radishes will become pitty, spicy, and possibly split if they have too much heat or inconsistent moisture. So, you’ll need to ensure they receive enough water.
The extra compost should help keep the soil cool, retain moisture, and give the plants enough nutrients to produce a healthy bulb.
Generally, you do not need to add more fertilizer outside of the compost since radish is not a heavy feeder and can be negatively affected by over-fertilizing.
6. Harvest And Store Radishes
Most radishes are ready to harvest within 28 to 60 days after sowing. For the best taste and texture, you must pick radishes within the recommended time frame indicated on the packet.
As a result, you will need to note the date you sow the seeds and be willing to harvest them even if they are not as large as you expected.
Once harvested, you can store radish for up to 6 months, depending on your chosen method. So, do not panic if you have an abundant harvest.
Tips For Direct Sowing Radishes
If you plan to grow radishes in the garden, you can do so quickly, provided you make the necessary preparations.
Firstly, you will need to place an inch or two of compost on the surface of the growing area. This will provide moisture, nutrients, and a suitable growing medium for the tender roots.
Next, you’ll need to ensure that the temperature is between 40 and 95 °F. Remember, radishes are cool-weather plants but can tolerate some heat at the risk of a spicy flavor.
It would help if you kept the area weed-free since radishes do not do well around competition.
Cover seedlings with a fine mesh to protect them from extreme weather conditions and pest damage to the leaves.
Avoid planting radishes where you previously grew other brassicas, especially if they were affected by soil-borne diseases in the past.
Thin radishes as soon as possible to avoid overcrowding plants. Ideally, you should have 1 plant per inch. However, the exact spacing will differ based on variety. See the label on the package for specific instructions.
How Long Does It Take To Grow Radishes From Seed?
Radishes take between 28 and 60 days to grow from seed to harvest, depending on the variety and the temperature in which they are grown.
Should I Soak Radish Seeds Before Planting?
You can soak radish seeds before planting, but it is unnecessary since they germinate quickly. However, consider placing the seed starter tray on a heating mat to encourage faster germination.
What’s The Best Way To Plant Radish Seeds?
The best way to plant radish seeds is to sow seeds directly into compost-rich soil, thinning them as they grow. You can also use a multi-sow technique and transplant seedlings or create short rows and sow seed directly.
How Many Radish Seeds To Plant Per Hole?
Plant 4 to 6 radish seeds per hole if using the multi-sow technique, spacing the hole 6 inches apart. You should aim for 4 radishes per hole, removing the weakest of the batch as they grow.