Beginning in 2013, I experienced problems growing radishes.  This year, I noticed that the
beets were under-performing.  A little reading revealed that the cause was most likely root
maggots.  The suggested solution was to cover the crop with fabric row cover.  I came up
with the following solution:

First, I built 1′ x 4′ frames  out of strapping  with chicken wire domes covered with fabric
row cover.  I planted beet seeds in  two rows 8″ apart.  I then planted a row of radishes between
the two rows of beets.  Here is what that all looked like.

Beet/Radish enclosures from a distance

Planting beets and radishes

The bed two weeks later

As you can see from the last photo, this method works very well with no insecticides
needed.  Please let me know what is going on in your garden.

All the best,
Greg Garnache