A radish growing experiment!

Like onions, radishes are easy to grow. Just sow some in standard soil, water well and in about a month's time you have a tasty addition to your salads. That's the theory anyway...

Just plain old everyday soil that has not been fertilized or heavily amended is supposed to be okey-dokey with most radish plants. According to the experts, too much nitrogen will give you a lot of tops with no root development. The same goes for overcrowding the little guys too! You need to sow them about 2 to three inches apart just below the surface of the soil, water on a regular basis and supposedly that's about all you have to do. Did you know that the tops are also edible (a little known fact) and also make a great 'peppery' addition to spring salads? I've gotta try that one myself!

The problem with some radishes, it seems, is that sometimes the roots just don't develop very well if at all! Or, they might be pithy or hot! I've been given all sorts of reasons why this might be so. The two chief being overcrowding and too much nitrogen in the soil. Other reasons have included very hot weather and under-watering. To find out if these were true, I wanted to do a little experiment to quantify this effect by tracking some of the variables that might affect their growth patterns and ultimate development.

---------------------------The Experiment

For this experiment I chose the Cherry Belle radish variety as it is very popular in my neck of the woods and tastes great! For the growing area, I chose a one foot square are in a raised bed in mid May 2013 (cool temps) where I planted one seed two inches apart from its neighbor – this arrangement allowed me to place 25 seeds inside the foot square area in such a manner that there was no other plants growing any closer than 2 inches (see chart). A situation that satisfied the requirement that many say a radish need to reach its full potential.

The soil I used was the soil that has been in place in the raised bed for a number of years. After digging below the surface, I determined that there were earthworms present (a great indicator that the soil is somewhat fertile as worms will not hang out in poor soil or soil that been over fertilized). So, the requirement that the soil not be nitrogen rich was also checked off.

The test area was watered by hand on the days when it didn't rain and a cover was placed over the area on days when the temperature got above 80°F. So, then, all the variables were covered pretty well. As a part of this experiment, I maintained a log of these factors in a data file, the results of which will be made available as a pdf document.

-------------------------The Variables

On a daily basis, I measured the following factors: 1) the daily hi and low temperatures, 2) the soil temperature at mid day two and a half inches down in the root zone, the condition of the soil (wet, damp, dry) each morning and 3) the general condition of each of the 25 plants whereby any root development was noted.

Recording all this data meant a rather demanding schedule to maintain for a whole month, but it seemed worth it to me to see if I could figure out which radishes developed well and which did not (and if not), why not!

------------------------Day One

As a part of the initial preparation, I assembled a simple planting grid using firing strips, nails and

some string. The grid was set up so that each seed would be at least two inches away from another seed, so as to allow for lots of growing room. This assembly took about thirty minutes.

Next, I lightly dug up a square foot area in a raised be out back. I then used my finger to make 1/8 inch depressions in the soil below each of the grid crossings. Each depression received just one seed and was then covered over lightly with soil. The soil was then patted down to insure a good soil to seed contact and watered the area lightly.

I also constructed a simple data file using FileMaker Pro to help me keep track of the variables I described earlier in the text. Here is a sample of what one entry might look like at left. Clicking on it (or any graphic) will enlarge it for easier viewing. 

Update: Three days later, on May 16, six radish seeds had germinated. 

Update: March the 24th and the radish plants now are developing true leaves! Click on the picture to enlarge it!

I WILL UPDATE THIS ENTRY FROM TIME TO TIME OVER THE NEXT MONTH SO AS TO TRACK THE PROGRESS OF THIS MOST BURNING QUESTION...

Update: June 15 2013 - Well, baring some last minute miracle, I'm sad to report that this experiment was pretty much a failure on just about all counts. Of the 25 onions that were seeded, only one has amounted to any thing. It was 2 cm wide and about  about 3 cm long and weighted in at only 5 grams. I plan to do this experiment over again, but will change two factors; 1) I plant to double the growing space between the radishes by cutting the number planted in half (12 this time around) and 2) I will be using a blend of Miracle Gro potting mix and sand to grow them in!