depends on how tall your tree is---in nature it is not regarded as in the front rank for altitude attainment but under good conditions it can reach over a hundred feet. tiny seeds should be fertile (after they are released from the cup-shaped pods (aka "gum nuts"). the seeds need to fall on a cleared area (not in grass and ground cover)in a sunny, warm, and moist place for germination outdoors. in the PNW they are best germinated indoors under similar conditions. FWIW, my glaucescens is about 50' while my nitens of similar age is about 70' tall.