With new plantings underway it is a timely reminder to ensure the bud union, or the bench graft union is 150mm above the soil surface. Consider also that the tree inevitably sinks after planting and irrigating/rainfall. If the bud/graft union is at or below the soil level, adventitious roots will grow from scion. This will negate any dwarfing effect of the rootstock. Your trees will become vigorous, outgrowing their allotted space.
There is no easy way to address the problem once the trees have established, except pulling them out and re-planting again. I would say scion rooting is a serious problem in our orchards, significantly contributing to variability and lowering orchard profitability.
Planting at the right depth, having this attention to detail at the start, will save you a world of pain & $$ later – Do it once, do it right.
Dean Rainham
Agfirst Horticultural Consultant
