How to grow Japanese radishes in the Midwest and harvest them.

Good evening folks. I wanna find out how could we grow giant Japanese radishes in the Midwest and produce a good crop of them for fall to provide for ourselves and others. I've never grown radishes before, but I'd like to find out the benefits of growing and eating radish for health reasons. Anybody went to Japan to see the giant white radishes before? The southern part of Japan was too ashy to stay out according to what I've heard. These radishes make world records and stuff like that. Are there any ways to use the radish as a meat or tofu subsitute? If anybody has grown any radishes like that before please reach me and chat so we can share some of your expereinces of growing the crop. Take care.

Hi Blake,
How wonderful you are interested in the long, white radishes. I have grown Daikon Radish seeds from Baker’s Creek Rare Seeds with great success in zone 6b.

Because of their length, I planted the seeds in a raised bed. They grew 2+ feet long! When I harvested them young, they were sweet and mild. If I left them in the ground too long, they turned pithy inside and did not taste as pleasant.

An organic farmer I know in Kentucky grows them as a cover crop and leaves the roots in the ground as soil builders.

The attached photo show where I planted the seeds in rows in August 2020. I learned they were planted too closely, so I had to thin them and ate the sprouted thinning. Yummy!  I apologize that this is my only photo of that experience.

Best wishes on growing!

Very good bed! Is your bed wide enough to have Sakurajima radishes at this time to gain their original form as they had in Japan? The radishes over there were much larger cause of soil conditions. What type of conditions they need for the radishes to grow larger?

Hey. Thanks for the introduction to a new variety to me. The Sakurajima radishes definitely seem worth growing, perhaps more so than the daikon we currently have.

I looked them up and found that they are named after the volcanic area they are from. The soil type is apparently mostly pumice and volcanic ash. I found this which has info on the area as well as some about the radishes.

https://www.env.go.jp/park/kirishima/Phenology%20Calendar%2C%20Sakurajima%20%20%28English%29%20.pdf

In the link it says, "The soil is similar to a wasteland containing pumice. The moderately lean, well-drained earth is excellent for growing radishes as it is easy to control nutrients and water content."

I'm not sure about the specific mineral contents of the volcanic ash, (which may or may not play a significant role in the really large sized radishes,) but it seems somewhat mechanically similar to sand. I imagine, again mechanically bio-char may act in a similar way to the pumice.

If I were to try and replicate the conditions in japan, with what I have on hand, I would use char that has been soaked in compost tea, mixed with sand in a deep bed. I would keep them watered as needed and might include some sea-salt every once in a while.
This is pretty much what I already do but I also add as much organic matter as I can so that I don't have to water/feed as regularly.  Our radishes can get to a decent size, (~20" long, 2 1/2" thick at top,) if sown at the right time, mid-late summer, but they are a long variety. If I find some Sakurajima seeds, I think I'll give them a try and see how they do.  

Anybody growing some of that radish right now? I'm extremely interested in the Japanese radish for my stir fries and soup Asian style. If anybody has seeds of them, please reach me in the Purple Mooseage page so we can talk about my interest in them and go from there.

Sakurajima radishes are super specific to that volcanic soil and environment (it's quite far south, not sure what zone, but it's warm down there), I'm not sure I'd bother trying them outside of it. Other types of large white radish grow easily enough (I have several hundred out in my yard right now, they took zero effort).
But, you can buy the seeds, and Baker Creek has a nice write up about the radishes with some great old pictures. https://www.rareseeds.com/blog/post/sakurajima-radish-the-worlds-largest

Hi Blake, I don’t know much about growing the big radishes. As far as eating them, though, there is a Chinese method of drying strips of radish in salt and sugar that results in a chewy almost “meaty” texture. You can find this preserved radish in Asian grocery stores. I have not made it myself, only bought it, but seems like it would not be difficult.

Here’s a blog about preserving radish in the Chinese style https://thewoksoflife.com/preserved-daikon-radish/

M.K! How you been? Looking forward to seeing you on your online meeting tonight. By the way how are the rest of your crops? And you planted some radishes before? I'm interested in planting some radishes this late summer and what are some health benefits to them?

I grew torpedo radishes as a  cover crop.
They failed to penetrate my hard soil much at all, but they did form giant roots above ground.
They were too hot to eat cooked or fresh, but they were (barely) acceptable as a vinegar and sugar pickle.
The real treat was the foliage and the seed pods.
They were still spicy, but in a good way.
The plants were endemic to my yards for a while but have since died of.

The huge sakurajima radishes take a long time ( five months) to mature in the original location. The seeds Bakercreek are selling are the earlier maturing type of 90 days. Still, it can be tricky to grow in midwest as it doesn't like hot weather (can't be sown too early) and cold temperature down to lower 20s will damage the above ground parts. Sakurajima radish needs loose and fertile soil with plenty of room. It should also be planted in a tall hill as the rosette of leaves tend to bend downwards. Most reviews on the bakercreek site aren't very positive as people have high expectations and it's certainly not as easy to grow as the regular daikon radishes.

Could they be planted in greenhouses to be ensured better climate conditions?

Blake Lenoir wrote:M.K! How you been? Looking forward to seeing you on your online meeting tonight. By the way how are the rest of your crops? And you planted some radishes before? I'm interested in planting some radishes this late summer and what are some health benefits to them?

Hi Blake, I do grow radishes, but just a golf-ball sized white radish, and I really grow them for the leaves and pods more than for the roots.

I prefer sweeter and mild ones to spicy ones. Any sweeter Asian radishes that will withstand Midwest climates in zones 5 and 6?

Blake Lenoir wrote:Could they be planted in greenhouses to be ensured better climate conditions?

I'd say that will help a lot witg season extesion. How about cakling Bakercreek and ask about it. They certtainly are able to grow jumbo size radishes there.

The secret of sweeter radish is the cool weather.
For Kimchi and winter storage, try Korean radish seeds.
Korean radish is shorter than Daikon, but the flesh is denser and crunchier, perfect for making winter kimchi and Fall storage.
You can buy seeds from Kitazawa, Etsy, eBay, or Walmart. Make sure the radish is not Altari radish, a small radish type.
I bought Kitazawa seeds from Walmart at the same price but with free shipping.
In zone 6b, direct sow radish from early August to the end of August. A light frost sweetens the radish, but don't let the roots freeze.
https://en.wikipedia.org/wiki/Korean_radish

Anybody tried some Chinese ones that said to taste like pears? They were green and last into the winter. I've seen that type of radish from Baker Creek.