[permaculture-oceania] Arrowroot, tomatoes and tools

[jedd]

 Howdi,

 A few quickies.

 Queensland Arrowroot (Canna indica)     [1]
 .v.  Arrowroot (Maranta arundinacea)     [2]

 Wikipedia suggests both are the source of arrowroot flour, however
 other sources indicate that the Cannas aren't useful for this purpose.
 What's the low-down?

 - - -

 Can other plants (especially eggplant, capsicum/chillis) be planted
 out as seedlings in the same way that tomatoes can - ie, buried maybe
 a foot deep with the top few leaves showing.

 Apart from drought resistance, do we know of any research into any
 changes to productivity or cropping period of plants so planted?

 - - -

 Related - has anyone designed a custom tool for digging a 30cm deep
 by say 8ish cm wide hole, without disturbing neighbouring plants?
 I've been tossing around some ideas involving galv pipe and hinged
 bits at the end .. but if this wheel has already been invented ... ?

 taa,
 Jedd.

 [1]   http://en.wikipedia.org/wiki/Canna_(plant)
 [2]   http://en.wikipedia.org/wiki/Arrowroot