I'm going to guess it's your soil which you should have tested (see below). Not only a nutrient problem but a soil tilth issue as well.

Check with your state's Extension Service. Each county should have it's own Cooperative Extension Office which provides free publications and information for the asking. They will have valuable vegetable/gardening tables available specifically for your area determined by universities and horticultural research scientists who have collected data from growing those crops in your state. Your tax dollars are already paying for this service so you may as well get some use out of it.

My suggestion to you silverwind is to get your soil tested. Your Extension Service can provide you with soil testing information. Mine was only $9.00, less than the cost of some strictly pH tests, and far more thorough. No guessing at what might need to be added, no money wasted.

See how detailed these examples are:

{{gwi:4005}}

Vegetable Planting and Planning Calendar for Missouri (download the pdf) complete with spring and fall planting dates (underneath the spring planting dates for appropriate crops), how much to plant per person, etc. They can also tell you the average last frost date for your area and ideal planting times for specific crops and varieties in your area.

Here is an excerpt:
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Next time try a 1x1 or 2x2 raised bed with light, fully, professional growing mix instead of your existing soil.

Here is a link that might be useful: On Soil Tilth

I posted on this once, though about red meat radishes, which are a little different. Planting them in fall, in loamy soil, made a huge difference. Anyway, maybe this discussion will help, if only so you know you're not alone. :)

Here is a link that might be useful: radishes not bulbing

I have best luck in late fall or early spring, in cool, moist conditions with loose, fertile soil. That usually produces crops like {{gwi:57835}} and {{gwi:57836}} which are mild, crisp and tender, without being tough and woody.
Bill P.

I've had this problem too. Last year my first crop of radishes had about a 90% bulb rate. The second crop was only about 50%. The last batch didn't have bulbs at all. The first two batches were in the same place, but the third was different. The second batch had nitrogen worked into the soil. The third didn't have a lot of sun. I didn't water as scrupulously with the second and third batch. On that link, jimster said the main causes of radishes not bulbing was:
1. Excessive nitrogen fertilizer.
2. Not enough hours of sun.
3. Magnesium deficiency.
4. Not a steady supply of moisture.

My soil's been tested and had plenty of magnesium. As for the others, they certainly could have been the problem. I have very sandy soil that drains really fast, even though I work lots of organic matter into the soil. Things grow well enough, but I have to water constantly (this year I'm experimenting with mulch to see if that helps).

My radishes this spring have done really well, with nearly all of them bulbing. I've been watering nearly every day though and they have 6 hours of sunlight. Plus it's been a cool/mild spring here in MN and I hear radishes like that sort of weather.

i have radish seedlings and im worried about bugs, is there a way to stop them? I hate bugs, i guess im just scared of them, ive wanted to get a cherry tree but im terrified of maggots so thats a nono for me, how can you get rid of bugs? --- for radishes

Bill

Can I ask what is the Dawn for and how do you use it? My radishes aren't doing too well either.

Thanks - Val

Hi Val. That is the big bottle of Dawn Dishwash liquid. I had a big ol heavy cast iron double sink left over from remodeling so the idea occurred to run a pvc pipe along the garden fence, build a stand out of scrap lumber for it to set in (or on) and have a place to get a cold drink of water till the water gets too hot, wash my hands and rinse off {{gwi:57837}}, like {{gwi:57838}} and {{gwi:57839}}.

The dishwashing liquid just came in handy for washing my hands after digging in the dirt in the garden. I did however, also find that a couple of squirts of it mixed with water in a hand held spray bottle would turn soft bodied aphids into mush, and it wound up being about the only thing that I had to use for insect control in my garden last year.

We have had an unusually high amount of rain here this spring and that may help boost the insect population. I noticed a couple of pepper plants and one cherry tomato plant in between showers yesterday, that had some leaves with holes eaten in them, so I will have to make a closer inspection today and see what I have to do.

To get back on topic, I did not plant any radishes this spring, ran across a packet of seeds the other day and thought that it might not be too late, but know that hot weather should have already been here, and that decreases radish production and quality dramatically in this area.
Bill P.

Keeping the pH level of your soil at a fairly neutral level (6-7) will greatly improve your success in your radishes producing a good root/bulb. If you have a high nitrogen content in your soil, you will see large green tops, but no bulbs.

When you plant your radish seeds, make sure not to plant them deep. A good practice is to sprinkle the seeds across the top of the loose soil, and then sprinkle a little soil over the top of the seeds. This method ensures your seed is not getting planted too deep. In fact, the seeds can sometimes be slightly visible to the eye, and that is still an acceptable depth.

Crowding can be a big problem as well. Keep your radishes thinned to about 2 inches apart, so that bulb production is encouraged. Avoiding crowding will be a successful practice. Radishes will also become deformed if you allow them to grow too close to the others.

Radishes do best with fresh soil. Adding a little sand to the soil never hurts, either. Make sure the soil drains well, always stays moist, and is fairly loose. As far as the fresh soil is concerned, this basically ensures that there isn't a family of root maggots living in it to eat away at your radish root or leaves, thus producing a good bulb.

Here is a link that might be useful: Radish Garden - Help! My Radishes Aren't Bulbing