Why Won't My Pear Tree Pollinate?

Pear trees that flower freely but set little or no fruit are most likely experiencing a pollination failure. Unlike some fruit trees that have a degree of self-fertility, most pear varieties are self-sterile and need a compatible partner tree nearby to produce a crop. Getting pollination right is the foundation of every pear crop.

Pollination groups and compatibility

Pear varieties are grouped into pollination groups numbered roughly 1 to 5 based on their flowering time. Varieties in the same group, or in adjacent groups with overlapping flowering periods, can pollinate each other effectively. A Group 3 variety can pollinate Groups 2, 3 and 4. A Group 1 variety cannot effectively pollinate a Group 5 variety because they flower weeks apart. When choosing a second pear to pollinate your existing tree, check that it is in the same or an adjacent pollination group.

Triploid varieties

Some pear varieties produce pollen that is sterile and cannot be used to pollinate other trees. Beurré Bosc is one example. If your tree is a triploid, it cannot act as a pollinator and you may need three trees — two compatible diploid varieties that cross-pollinate each other, plus the triploid. Check the characteristics of your specific variety before assuming it can contribute to pollination.

Distance and pollinator activity

Bees are the primary pollinators of pear blossom. The standard guidance is that a compatible pollinator pear needs to be within approximately 50 metres, though bees routinely travel further. However, pear blossom opens early in March when bee activity is still relatively low and cold weather can suppress flying entirely. In cold, wet or windy springs, even well-matched trees nearby may fail to set fruit because there are not enough bees active during the blossom period. Hand-pollinating on the few warm, still days during blossom by transferring pollen with a soft brush between two varieties can significantly improve set in difficult years.

Compatible variety combinations

Some well-proven pollination pairings include Conference (Group 3) pollinating Williams (Group 2/3) and vice versa; Beth (Group 3) works well with either; Concorde pollinates Conference. The most reliable approach is to plant two or three compatible varieties rather than relying on a single tree and hoping for suitable neighbours.