How long before moving plants?
 

When I got my plants a week and a half ago, I placed them in the aquarium in a manner to help them get nutrients, light, etc to help them start roots. Most of them are stem plants and didn't have much in the way of roots when I got them.

As of today, most of the stem plants have at least 3" roots growing above the substrate, enough that I could make new plants from them if I so desired (not yet though). Just about everything is sprouting new leaves that look nice and healthy.
The slowest growing is the Rotala macranda which most have little nodes where the roots would come out. Some have short roots that have made it into the substrate.
I know these are known for being difficult to get established, so it looks like things are going well.

So the plants are not where I want them to be. I wondered, how long do you think I should wait, or what signs do I look for before moving them to their permanent spots?

Stem plants can be moved anytime. Substrate-rooted plants are more exacting about being moved, some like crypts very much so, swords are Ok as long as it is not too often. Swords can actually benefit from occassional re-planting.

Stem plants develop roots all along the stems, this is natural in many of them. As they grow fast, you will probably pull them up regularly, cut off the lower portions (which often lose their leaves or look tatty) and replant the top portions. If you don't do this, some of them will grow across the surface and become a nuisance, unless of course you want them on the surface, but when many of them do this the lower leaves will fall off.

Plants on the surface are almost always a positive for the fish and the lower plants which usually do not need as much light as many think. It all depends upon the fish and plants and how you want the aquarium to look.

Byron.

You can move them with your next w/c. Just see how you'd like to lay the tank out first and them move them to a permant spot (so you don't wind up moving them each week that wouldn't be too good).
The Rotala's I had found produce more roots int he gravel then alongside the Stem like for example the Ludwigia do, so you may find their roots dev in the gravel when you're moving them around.

So if I'm pruning without wanting to replant any cuttings, trimming from the bottom is a better way to go?

Absolutely. It is a feature of almost all stem plants that as they grow the lower portions sort of wither away leaf-wise. Probably every week during the pwc you will want to trim them, or maybe every two weeks, depending upon growth rate in your tank. I do my Pennywort every two weeks, sometimes more, to keep it "fresh". The Wisteria in my 70 I have let go, and it is bare stems along the bottom 2/3 with incredible bushiness at the top and it is floating along the surface. I want that, because I have Chocolate gourami and pygmy sparkling gourami spawning non-stop in that tank, and the thick floating plants (it is very thick, believe me) protects the fry so at least some of them survive. I don't want more or I would take thenm out to a nursery tank. I just like to see nature naturing, as I call it.