We had a group of Northwestern University engineering majors tackle the problem of using RFID in a garden setting a couple of years back as a class project. They discovered the capture rate of the RFID tags increased to 20 feet if the reader used a spiral wave pattern instead of the traditional line of sight straight lines. Straight line of sight failed more often than not because of obstructive leaves, branches, etc. I experimented with T-budding a RFID chip under the bark of a spare willow seedling in the nursery but the little 'antennae' that I had left exposed beyond the bark corroded after a couple of years. Contact me at my personal email address for name and make of equipment that they found worked under mulch, couple of feet of snow or buried within one of our boxwood hedges. Boyce Tankersley Director of Living Plant Documentation Chicago Botanic Garden btankers@gmail.com where a week of above freezing temperatures has finally melted most of the snow to the flowering delight of Galanthus, Eranthis, Iris reticulata, Adonis - and gardeners. On Tue, Mar 17, 2015 at 10:45 AM, penstemon <penstemon@q.com> wrote: > > We have so much discussion on various forums over what is sand or grit or > gravel; but rock mulch! How large is that and what shape? or is it just > another name for some of the 3 above. > > > Pea gravel. What I believe is called shingle in the U.K. Years of applying > the “annual approved topdressing” (I read a lot of Graham Stuart Thomas), > the raised beds have become mostly gravel, with some clay. > Here, we mulch with shingle, but only after a hailstorm. > > Bob Nold > Denver, Colorado, USA > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > _______________________________________________ pbs mailing list pbs@lists.ibiblio.org http://pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/