This weekend, I attended the 7^th of an 8-class series on Biodynamic Gardening/Farming at a local college.  The topic for this month’s class was on “Growing Plants and Weed Management.”  With regard to the “growing plants” segment of the class, the instructor (who also farms the land at the college), introduced me to the concept of “pricking out,” which means transferring a newly germinated seedling at the proper time to a larger container (note that "pricking out" is a form of transplanting and is not synonymous with "thinning out").  According to the instructor, “pricking out” is necessary when a plant is grown in tight quarters, say in a tray or pot (see photos), with many other seedlings.  Timing to “prick out” is critical.  “Pricking out” should only be done after the seed leaves and first set of true leaves have emerged and are fully formed.  At that stage, the gardener grasps the seedling gently from its base, leaving as much of the potting mix/compost attached to the root system.  If the true leaves have become too large because the gardener did not “prick out” timely, the gardener will trim the tops of the plant slightly as well as the roots, prior to transplanting the seedling into a larger pot/container (the instructor explained that  trimming the tops of the plants reduces the stress on the plant’s root system because there would be less for the root system to support).  It should be noted that the seedlings should be watered both before and after the transplant. 

I have yet to try this out on my own seedlings, but if the plants on the farm at the college are any indication (they appear to be healthy and strong), this method may well be worth the experimentation.