a picture would be worth a thousand words... if i understand your premise.. you want to 'top' a 30 foot plus tree.. to about 18 feet ... i just cant conceptualize such.. w/o a pic ...

and probably get you an ID ... if your ID might be off ... are you sure on it???

you might mention in future posts.. that you are in Australia ...

ken

FWIW, c. capitata is normally an evergreen dogwood and rather tender below zone 8. it has sometimes been "confused" by both taxonomists and nursery people as a form of c. kousa (a deciduous species) and with the usually evergreen but hardier c. kousa ssp. angustata (aka c. angustata OR c. elliptica). in any case, if you have a leggy tree, you MIGHT have the result of trees being planted too close together and the resulting competition for both space and light making the trees tall and sparse and/or not enough summer water causing drought stress (all these plants come from summer wet areas of china and japan). hope this helps. good luck.