What is a Rootstock?

• Fruit, nut and other trees generally consist of two parts: the rootstock or the lower, underground portion of the tree; and the scion or the tree part above ground. The rootstock controls many tree attributes including size, fruit bearing age and quality. Trees in the same plant family are generally used as rootstocks. This tree production method is centuries old.
  
  

Recommended Rootstocks

• Almond trees are generally grafted on the rootstocks of peach, plum and hybrids of almond and peaches, cite Jules Janick and Robert E. Paull in "The Encyclopedia of Fruit and Nuts." Using these rootstocks is important, as almond rootstocks are prone to fungal disease. The trees also suffer from low oxygen levels in the roots when growing in overly moist or poorly draining ground.
  
  

Peach Rootstock Advantages

• Peach is the preferred rootstock for almond tree for several reasons. When grafted onto peach trees, almonds have a more vigorous growth habit. The trees also produce their fruit sooner. Peach rootstock gives almond trees a higher survivability rate by increasing the resistance to crown rot disease. These trees are more tolerant of high soil moisture and less prone to crown galls.
  
  

Plum Rootstock Characteristics

• Although plum is also used as rootstock, only certain plum species are suitable. These species include Prunus domestica, P. salicina and P. cerasifera. Plum is less preferred than peach, as it is not compatible with all almond varieties. Some combinations of plum and almond grow well but are not very fruitful. However, plum rootstock offers the advantages of having a high level of resistance for wet soil, nematodes and the fatal oak root fungal disease.