Thursday, April 29, 2010

Growing radishes in the desert

Growing plants in the desert isn't easy, but it can be done.  Radishes are grown between tax day and the end of June (ish, this depends on the year's weather which is anything but predictable).  Radishes don't like to grow when it's super hot.  Sometimes in the desert, it's consistently above 100 by the end of June.  Other summers you can go almost the entire summer without getting above 100.  With enough water and shade, you could grow radishes through a cool summer and into fall.
At the ranch, we have lowered beds (as you can see in the picture).  They're also called sunken beds.  These beds are dug deep into the ground, about three feet (I wanted to do four, but got tired lol!).  Then we put composted horse manure back into the pits.  This way, the bed is extremely fertile but it's also light and fluffy and this helps the plant to grow and expand as well as its roots to grow and expand without much effort.  
The deep bed and the fluffiness of the bed also hold water in so that you don't have to water as often.  Since the bed is sunken about 6 inches below ground level, you can flood the beds without worrying about losing the water to run off.  If it rains, the rain goes into the bed instead of pouring off the bed and onto the paths to be wasted.

Of course, this system wouldn't work in areas with decent rainfall because too much water would get to the plants and cause the roots to rot. But we only get three inches of rain annually on average (Imagine, locals were complaining this year about all the rain we were getting because we got double the annual average-a whole 6 inches!!!).
When planting radishes, most directions tell you to plant about a half inch below the surface of the ground.  If you plant anything a half inch below the ground in the desert, it will never grow.  The first couple inches of the ground dry within hours to crumbly dust. You'd have to mist the ground constantly to keep it moist enough for seeds to sprout, especially when the summer heat hits.  Yesterday I was out in the garden at noontime (never a good idea) for about a half hour and got burned and it's not even summer yet!  So plant radish seeds about four inches below the ground.  
What I do is soak the planting area the day before and then plant the next day when the ground has dried out some.  Then I scrape away the ground until you get to the moist soil and plant the seeds about an inch below that level.  I think of the top dry section as mulch rather than soil.  You wouldn't plant your seeds in mulch.  You would move the mulch and plant under it
Another tidbit I learned about growing radishes this year is that they need to be planted about an inch apart, but then they must be thinned when they're a few inches tall to 3-4 inches apart.  The radishes in the picture above are beautiful, but they were on the edge of the radish patch.  The ones in the middle are tiny and didn't develop well because I didn't realize I needed to thin.  I'm hoping they'll still grow now that they've been thinned.  This advice has nothing to do with the desert really, except that it's probably even more important in the desert garden than in a regular garden because the plants have to compete more for water, even with sunken beds.  When the plants are too closer together even for normal gardens, they're WAY too close together for the desert garden.