On September 8th I started my first attempt to germinate lettuce seeds in rockwool.  Reading up on how to prepare rockwool, I soak it in water overnight but I added a bit of vinegar to the soak in order to reduce our city water’s pH from the mid 7’s down to the mid 5’s.  One reason supposedly to do this is to neutralize any base left in the rockwool from sources like limestone, and supposedly a more acidic water helps in germination and growth.

What did we experience?  Nothing.  The lettuce seeds started just a couple of days earlier in soil are germinated and looking great.  Several days after this failed experiment was started, I seeded some new rockwool with two different lettuce seeds and some swiss chard and they have mostly germinated as of this morning.

For this second rockwool germination experiment, I took some of the rockwool from the previous preparation and soaked it several times in plain tap water to help pull out the acidity.  Additionally this set was put into a plastic container that had a lid on it.  Why was this one successful and the previous one was not?  There are two potential variables I have identified.  First, it could be the vinegar.  Second, it could be the humidity dome (aka lid) versus open air.  These will be two things we will keep in mind as we press forward in this adventure.