What is a rootstock? A fruit tree’s rootstock controls primarily the tree’s size, precocity (how early the tree bears fruit), cold hardiness, and partly its disease resistance (such as fire blight). In order to grow a reliable and high quality fruit tree, growers graft the scion, which is above the ground and responsible for the fruit’s characteristics and disease resistance, onto the rootstock, which is underground. Grafting is a horticultural technique growers use to combine the tissues of two plants so that they continue to grow together with certain desired characteristics. However not all trees are grafted. Seedlings are trees grown from seed and aren’t grafted. Moreover, in general seedlings grow to be larger than grafted trees, stronger, more hardy, and more likely to survive frosts. 

Tree Size

Rootstocks control the tree’s size. Therefore when the tree is fully mature, it can range from being dwarf (6-8′) to standard (20-30’+). However with proper pruning, you can also control trees on semi-dwarfing or semi-standard rootstock to grow to a smaller size.

tree size

Precocity

What is precocity? Precocity measures how early the tree will start to bear fruit from the time the tree is planted. Dwarf rootstocks are usually more precocious than semi-dwarf or standard rootstocks, which means they will bear fruit earlier. However the fruit cultivar can also influence the precocity of the tree. For example the Northern Spy apple tree usually bears fruit late compared to other apple trees such as Honeycrisp.

precocity

Cold Hardiness

Rootstocks can also control the tree’s cold hardiness, or the tree’s ability to tolerate cold temperatures. For example, the Budagovsky series, which was developed in the Soviet Union, is very cold hardy.

what is a rootstock? Cold hardiness

Disease Resistance

Rootstocks can also be resistant to diseases such as fire blight, collar rot, and woolly apple aphids. Many of the rootstocks that researchers have developed in the 20th century, such as the Geneva series for apples and OHxF series for pears, are made to be resistant to common diseases and viruses.

what is a rootstock: disease resistance

What Rootstock Do We Use For Our Trees?

Apple

We use different rootstocks such as dwarf (Bud 9 and G.41), semi-dwarf (EMLA 7, EMLA 111, G.890, Bud 118), and standard (we use Antonovka seedlings). From our experience growing in New York, we have found the Budagovsky (Bud), Geneva (G), and EMLA series to be great options since they are reported to be virus free and produce very healthy trees. Learn more about apple rootstocks in this article.

Apricot

We grow our apricot trees onMyrobalan 29C (standard), Marianna GF 8-1 (standard), Krymsk 1 (semi-dwarf) and St Julien(semi-dwarf) rootstocks.Myrobalan 29C (also known as Cert Myro) is the improved version of Myrobalan (Myro) and an excellent, widely adapted rootstock that has a vigorous root system. Secondly, Marianna GF 8-1 is very robust and adapts to all types of soil. Additionally it not susceptible to root asphyxia. Krymsk 1 is a dwarfing rootstock from Russia which produces trees about 50-70% of the standard tree size. Additionally it improves the fruit size and is more cold hardy than other rootstocks. Lastly, St Julien is a semi-dwarfing rootstock (producing a tree with a height of around 10′-15′). Additionally it is tolerant of most soils.

Cherry

We grow our cherry trees on standard rootstock, Mazzard (standard,16-20ft tall), Mahaleb (standard), and Krymsk 5 (90% of Mazzard size). Mazzard, which is one of the oldest known sweet cherry rootstocks is the most popular rootstock in North America. Additionally, it’s great for wet and heavy soils. Moreover it is It is generally more vigorous than Mahaleb, especially in poorer soils. Mahaleb on the other hand, is great for deep soils with good drainage. Additionally it is cold hardy, precocious, and deep rooted. Lastly, Krymsk 5 is a more precocious rootstock than Mazzard or Colt (bears fruit earlier) and very tolerant of stress conditions.

Pear

We grow our pear trees on Betulaefolia (grow standard trees around 20ft), Calleryana (also known as Call, 90-100% of standard size), OHxF97 (grow trees 70-90% of a standard tree size), OHxF87 and OHxF333 (grow trees around 2/3rd of a standard tree size) rootstocks. For European pears, the OHxF series, especially the OHxF 87 and 97 are great choices. Not only are they resistant to fire blight but they also produce healthy trees. Learn more about pear rootstocks in this article.

Peach

We grow our peach trees on Bailey and Lovell rootstocks which have high survival and make large trees. At full maturity, peach trees range from about 10-15′ tall with proper pruning. In fact without pruning, they can grow up to 25 feet tall. Moreover Bailey rootstock is slightly dwarfing and has yield efficiency as good as or better than Lovell.

Plum

We grow our plum trees on Myrobalan (standard 10-15′ tall), Myrobalan 29C (standard), Marianna GF 8-1(standard), Krymsk 86 (80-90% of standard), and Krymsk 1(semi-dwarf) rootstocks. Myrobalan 29C(also known as Cert Myro) is the improved version of Myrobalan (also known as Myro) and an excellent, widely adapted rootstock that has a vigorous root system and is the most tolerant of wet soils. It also has less suckering than a seedling. Marianna GF 8-1 is very robust and adapts to all types of soil. Additionally it not susceptible to root asphyxia but has a shallow root system.

Interested in growing trees? Discover more about trees in our guides or search our fruit trees.

What is a Rootstock? Video Explanation

6 thoughts on “What is a Rootstock?

  1. Pam Molle says:

    The NY9 Plum says it is grown on Krymsk rootstock but there is no mention of that rootstock on this page. What height will it get to be?

    • Surik Mehrabyan says:

      Hi Pam,

      Krymsk is a Russian rootstock, which has several advantages: the tree size is about 50-70% of the standard tree size, it improves the fruit size, and it is more cold hardy than other rootstocks.

  2. Pam Molle says:

    Help why don’t the rootstocks mentioned on the European plums correspond to the ones mentioned above? How tall does Myro and Cert Myro get?

    • Surik Mehrabyan says:

      Myro (Myrobalan) and Cert Myro (Myrobalan 29C) are very vigorous rootstocks. They are considered standard size trees (bigger than Krymsk), that can reach 10-15′. However the size of any tree can be controlled by doing summer pruning. Hope this helps!

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