I have only grown tomato plants one time - Sub-Arctic variety in a raised
bed when I lived in Alaska. I don't think that the experience carries over
very well though.

What I have now is two plants in a home-made self-watering planter. One is
a Sweet 100 and the other is a German Queen and they are growing at an
insane rate (over three feet and moving fast) and that is the problem or
will soon be. The planter is sitting up on a brick retaining wall in the
only decently sunny patch I could use on my heavily-wooded lot. I set up a
couple of prefabricated wire plant supports but the plants have both topped
those. Would it be safe to encourage the plants to grown over the top and
back down, draping over the front of the planter and down the wall? Do
tomato indeterminate tomato plants snap off under their own weight? Are the
stems "brittle" or are they even a bit pliable?

I guess that I can try to jury rig some sort of other support if I need to
but given that the planter is made from a Rubbermaid storage tub attaching
anything to it is a real trick and if I allow the water reservoir to get
even a bit empty the whole rig could become quite top-heavy.

Oh BTW: the Sweet 100 has quite a few tomatoes already even so the largest
is still in the grape size range.

--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com