Radishes are a delicious vegetable, with a spicy, fresh flavor that can enhance any meal. You can add them to a salad, bake them for a tasty snack, or cut one up for a treat all on its own. Despite how versatile radishes are, not everyone adds them to their indoor gardening list, which is a bit strange when you consider how easy these little red roots are to grow in your home. If you’d like to enjoy fresh, home-grown radishes year-round, learning the best way for growing radishes indoors is a good place to start.
Types of Radishes
There are a wide variety of radishes to choose from, so you can pick your favorites or try some new ones. Of course, when growing radishes indoors, you do need to choose the right variety, especially when you have limited space to work with.
Luckily, there are several small varieties of radishes that you can try out, including Cherry Belle, Early Scarlet Globe, Malaga Violet, and White Hailstone. These are all smaller radishes with fast maturity times, so you don’t need to wait too long to enjoy them. You can also choose larger varieties with longer wait times or grow a few types to mix it up a bit.
When choosing a container, be sure it can handle the full growth cycle of the radish since these root vegetables don’t like to be transplanted. Doing so could destroy your entire crop, so pick a container that can handle them from seed to harvest.
Your container can be long or round, as long as it has a depth of at least 6 inches for regular round radishes and up to twice as deep for elongated ones. Radishes also need to have a few inches between each plant as they grow, so be sure to choose your planter carefully.
The container you’ve chosen can be made of almost any material, as long as it is self-draining to avoid overwatering. If the radish roots are left in standing water for long periods, they may begin to rot.
The best soil for radishes is rich in nutrients, plus it should be permeable and well-draining to keep them moist without retaining too much water. You can buy any potting mix that fits these specifications or you can make your own at home to give you the exact amount you need for your radishes. A home recipe also allows you to adjust the mixture as needed if you plan to use it for other veggies as well.
Radishes like a lot of water all at once rather than sporadic sprinklings every couple of days. To water them properly, you may want to try the deep watering method. This requires you to place the radish container in a large sink and pour water over the soil until you see it flowing out of the drain holes in the base of the container. Turn off the water and let the container finish draining before removing it from the sink and replacing it in its usual spot.
This method ensures that the roots are getting the moisture they need to feed the plants and keep them healthy without the risk of damaging overwatering. To know when to water next, push your finger into the dirt next to a plant. Dryness to the first knuckle means it is time to water again using this same method.
You can also water normally, but make sure you thoroughly saturate the soil. You should see water leaking from the drainage holes which is a good sign that the soil is properly soaked.
These root vegetables need a lot of sun, so should be placed somewhere that will get 6 to 8 hours of direct sunlight each day. You can give them partial sun for about 4 to 5 hours if you have no other option available, though this will slow the growth of the radishes.
If you’re having trouble hitting these numbers, grow lights are a great way to supplement. Most commercial grow lights will work. Look out for LED or other high efficiency lights as these will cost less to operate, and reduce the risk of heat damage to your plants.
Despite how much sun these vegetables need to thrive, they are actually cool-season crops that do their best growing on the shorter days of the year. They can germinate in temperatures between 40 and 95 degrees Fahrenheit, though the optimum germination temperature is between 55 and 85 degrees Fahrenheit for the fastest growth.
Keep this in mind as bright locations are typically warmer. Too much heat can damage the plant, so make sure it stays in the above ranges.
How to Plant
Planting radishes is quite simple and easy to do. They do prefer to be sown right into the soil they will be growing in rather than transplanted, so if you’re going to start them indoors, it’s best to leave them there permanently.
Radish seeds are quite small, so it makes it tricky to space them out when planting. Rather than fighting with these little seeds, sprinkle them into the dirt of your container. Then gently pull the soil over the seeds using a garden fork.
After a week or two, the seeds will have begun to sprout. Now is the time to deal with spacing. You can thin them out to leave a space of about 1 to 2 inches between each of the plants, giving them room to expand as needed without crowding them.
If you’re starting with a seedling, sow them directly into their home container with the same 1-2 inches of spacing. Then, continue with your normal care routine.
Though you may think your radishes need the help of fertilizer to grow to their full, healthy size, this isn’t the case. If you do want to add some fertilizer, use only all-purpose, low-nitrogen fertilizer when preparing the soil for planting. Too much nitrogen will encourage lush leafy tops, which will reduce the size of the root, resulting in tiny radishes.
If your radishes aren’t performing well after 2 weeks, you may add another small dose of water-soluble fertilizer, though only do this if absolutely necessary. Radishes usually function just fine without fertilizer of any kind so this is often not needed.
When to harvest your radishes depends on the type that you’ve sown. Some early maturing radishes, like Cherry Belle, are ready to harvest in 23 to 30 days, while some Asian radishes may take up to 70 days to mature.
The best way to tell is to wait for about 30 days, then pluck one or two radishes from the soil. If they are the size you want, you can harvest as many as you need. If not, leave them be for a bit longer, though don’t wait too long to harvest. Radishes that spend too much time in the ground can become brittle and lack the flavor you’re looking for.
Growing Radishes Indoors
Radishes are an excellent, indoor crop that is easy and fun to grow. One of the great aspects of radishes is how fast they mature. This makes them a low time investment, and also a plant that you can reap the benefits of very quickly.
Have you grown radishes indoors? Let us know how it went!