Grafted Trees

Riversun offers an extensive range of certified fruiting and pollenizer avocado trees grafted onto a choice of clonal or seedling rootstocks. 


Avocado fruiting varieties are grafted onto Zutano rootstocks which are selected from a given mother tree to produce similarly performing seedlings. 

Up until 10 years ago seedling trees are what the NZ Avocado industry has been based on and although they require management due to their genetic variability, they produce satisfactory yields in virgin, free draining soils where there are no signs of Phytopthora root rot. We do not recommend seedling trees as replants in an existing Avocado orchard.

With no barriers to entry (ie. no PPIN required from the NZ Avocado Industry Council), anyone can purchase avocado seedling trees.


A clonal rootstock is a vegetatively propagated or cloned rootstock as opposed to a germinated seedling rootstock. Clonal rootstocks are genetically identical to their ‘mother tree’ with their strengths predictably repetitive throughout the orchard. Providing uniformity they are particularly important for high-density plantings and they also provide high-tolerance to Phytophthora root rot. The two main rootstocks (selected from South Africa) for large scale commercial production are Dusa and Bounty.

The procedures involved to produce clonal rootstocks are daunting: a small shoot of a rootstock cultivar is forced to produce roots in the nursery by a complicated procedure using plant hormones, grafting to a nurse seedling and etiolation (growing in the dark). The timeline required to produce such a tree is at least 18 months from germination to a nursery plant ready for delivery – adding significantly to the cost of the end product.

Clonal trees offer the following benefits over trees on seedling rootstocks:

  • Bred for higher tolerance to Phytophthora root rot
  • Clonal rootstocks eliminate the extreme genetic variability often found in seedling rootstocks
  • The uniform growth of trees grafted onto clonal rootstocks helps standardise orchard management
  • This uniformity makes clonals well suited to high density plantings
  • They are the ONLY option when replanting an old avocado orchard
  • May allow planting of more challenging soils (especially Bounty)

    NB: No avocado rootstock will tolerate waterlogged soils.

Hass on Bounty Tree