Anubias nana on driftwood?

I just purchased a couple of larger echinodorus (a paniculatus and a martii x 
osirus which Mike at Delaware Aquatics calls a 'red rubins') and I need to
rearrange my tank a bit.  

I've got several anubias nana which are doing quite well (their rhizomes have 
gone from 1/2" to about 3" since July) with their roots in the substrate.  I've
heard people mention that nana can be attached to rocks and driftwood like 
java fern.  Could anyone who has actually done this tell me:

    o how long does it take nana to attach to driftwood
    o how firmly do they become attached
    o is there any affect on growth rate
    o how does it look; are the white roots from the rhizome noticable
Also, how deep a substrate do I need for ~15" echinodorus?  My gravel depth
is 3", which is working fine for the small/medium plants I have.  Should I
'aquascape' a bit to get deeper substate in the back of the tank for my
two new swordplants?
Steven Hicks,            ILX Systems                  212-720-3148
steveh at ilx_com           111 Fulton Street            212-312-2983 (fax)
                         New York, NY  10038