The white stinkwood is Celtis Africana, and despite its common name isn't a stinkwood at all. We planted a 1.8m (total height in bag) one in May 2017 and it is over 2.25m (from ground level up) now, and doing well, despite the drought in the Cape. The tree nursery we bought from agreed with my impression that planting a smaller tree was better as it was less likely to be rootbound, and would get growing sooner. Also, I think transporting and transplanting anything bigger would probably best be left to the professionals. If we haven't had at least 20mm rain in the week in spring/summer, we make sure it gets 20 litres of clean greywater per week, all at once. Just note that there is also a Celtis sinensis which isn't indigenous, but apparently it hybridises with the Africana in Gauteng. I think its leaves are glossy whereas the indigenous one has matt leaves.