Grafting Pears on Quince BA 29 Rootstock: Interstem Techniques and Compatibility

Understanding Quince BA 29 Rootstock

Quince BA 29 is a popular dwarfing rootstock for pears, typically producing trees 10 to 15 feet tall—about half to two-thirds the size of standard pear trees. Despite the smaller stature, this rootstock yields heavily and offers resistance to pear decline, crown gall, nematodes, and root aphids, making it valuable in areas where those pests are prevalent.

Graft Compatibility and the Need for an Interstem

Not all pear varieties are directly compatible with quince BA 29. Varieties such as Bartlett, Bosc, Seckel, and Clapp’s Favorite often fail when grafted directly. To overcome this, growers use an interstem—a short section of a compatible variety grafted between the rootstock and the desired scion. Recommended interstem varieties include ‘Old Home’ and ‘Hardy’, though others may work as well.

Two-Step Grafting Process

The standard approach is a two-year process:

1. Year 1: Graft the interstem variety (e.g., Old Home or Hardy) onto the quince BA 29 rootstock.
2. Year 2: Once the interstem has established, graft the desired pear variety (such as Beurre Hardy) onto the interstem.

This creates a compatible bridge, allowing the scion to thrive. Some sources suggest grafting both the interstem and the final variety in the same year, but the two-step method is more reliable for difficult combinations.

Pollination Considerations

Beurre Hardy and similar dessert pears require cross-pollination. Good pollinizers include Bartlett and Bosc pears. These can be grown as separate trees or grafted onto the same tree. Ensure bloom periods overlap for effective pollination.

Key Takeaways

• Quince BA 29 reduces tree size but increases yield.
• Direct grafting of many pear varieties fails; use an interstem.
• Old Home and Hardy are proven interstem choices.
• Plan for pollinizers—Bartlett or Bosc work well.
• Two-year grafting sequence yields the most reliable results.

With proper technique, quince BA 29 can produce high-quality dessert pears with excellent flavor, often described as having a hint of rosewater.