Attach movieclip problems

Question

lets say I have a johnny_appleseed_mc and I make some seeds
that over a series of events will grow into apple trees.
the seed_mc is located in my library, and I am loading it
like this:
if(Key.isDown(Key.SPACE)){
this.createEmptyMovieClip("holder" , "100");
holder.attachMovie("seed_mc", "tree_mc",
holder.getNextHighestDepth(), {_x:johnny_appleseed_mc._x,
_y:johnny_appleseed_mc._y -50});
holder.x=johnny_appleseed_mc._x;
holder.y=johnny_appleseed_mc._y;
when i movie the johnny MC, the seed_mc doesn't follow
(good), but when I plant again (another seed) the original seed_mc
in the first position disappears and reappears in the new position
of johnny, as if the first seed was never planted. How do I make
the old seeds stick in place, and still plant new seeds?
(edited for clarity)

Answer 1

Well, I tried making a backup called file 102 (instead of
file 101)
and experimented creating this variation on the code:
i = 1;
k = 2;
onEnterFrame = function(){
itxt.text = Number(i);
ktxt.text = Number(k);
Key.addListener(myListener);
var myListener:Object = new Object();
myListener.onKeyUp = function() {
if (Key.getCode() == Key.SPACE) {
i = i + 0.1;
itxt.text = Number(i);
k = k + 0.1;
ktxt.text = Number(k);
Key.addListener(myListener);
onEnterFrame function() ={
if(Key.isDown(Key.SPACE)){
this.createEmptyMovieClip("holder" , i);
holder.attachMovie("seed_mc", "tree_mc", k,
{_x:Johnny_Appleseed_mc._x, _y:Johnny_Appleseed_mc._y -50});
holder.x=Johnny_Appleseed_mc._x;
holder.y=Johnny_Appleseed_mc._y;
trace("Holder Depth "+holder.getDepth());
//yields 100
trace("Tree Depth "+holder.tree_mc.getDepth());
//yields 101
well it works and it doesn't. For one, the depth jumps a lot
more than I thought it would - instead of +2 per unclick the of the
spacebar, it jumps in some kind of ratio, first 20 or thirty, then
40-50, then later by the thousands. The hold depth stays 1, even
though the seed depth keeps going up.
The seeds "plant", but their's this peculiar pause between
each seed for other actionscript. I put in a "move" actionscript
for the seeds to see if they were interacting, (a +y = 5) and
annihilate (remove clip) when getting to the other side of the
screen. The seeds would load, and wait for the first seed to
travel, annihilate, then move. You could load 20 or thirty seeds in
one spot, they would all wait patiently like divers in line, then
in succession, fly up and disappear.
While this is useful for making incremental "complete the
loop" scripts, it's entirely useless for simultaneous events. If I
set up my seeds to grow over a week period for example, it would
take a year for 52 seeds to work.