Seeds will not germinate in my Earthboxes!

[Azbill]

I saw the question on "can seeds be planted in an EB?" My problem is a little different, I have gardened in a dozen EB for three years now. My success planting seed ( kohlrabi, beans, kale, radishes, spinach...) has declined each season. This fall I have not been able to get anything to germinate.  Boxes have either ProMix or Miracle Grow potting mixture, wick is good, water level maintained, seed all tests fine when germimated in starter pots.  Transplants root fine in these same boxes.
 My location is Phoenix Az, so this is a good time for me to plant my cool weater crops. All ideas are appreciated.

[gardendoc]

How old are your seed? How do you store seed? The dry AZ weather can age seed much faster than than other places.

[Azbill]

My seeds are of various ages.  Except for the beans and peas all have germinated satisfactorily in seedling mix (for transplants). I tried presprouting the beans and peas ( for one attempt) and they presprouted ok.

[Tag]

To germinate seed in a hot or dry environment you may need to add supplemental moisture from the top. The top inch or so may not be moist enough.

[pepperhead212]

Though I have never tried them direct seeded in the EB, so I don't know what they would do for me, I start all of mine in small pots - 72 pots/tray - and transplant them in 3 weeks. 

I have found brassicas to start slowing down after 3 years stored at room temp where I am, and when 4 years old, even  the ones that come up are much slower (coming up and growing) than the rest, so I make sure I replace them after 4 years.  And given how small they are, there are always some left over!  I try to share them, so I don't throw them away at that point, but not everyone wants some of those strange Asian greens I grow!

[gardendoc]

 Some of my old greens seed is tossed around the back fence to grow and allowed to flower. Great for those pollinators on warm spring days in February