The Pollination of Rare Apple Trees

Apple Pollination

Some fairly new apple varieties are classified as "self-fruitful," meaning that trees can set fruit with their own pollen. Most types of apples are considered "self-sterile," meaning that they need pollen from another apple tree -- a different tree, but also a different variety of tree -- to produce a good crop. Even self-fruitful apple trees will produce more abundantly with cross-pollination, so backyard growers should always plant at least two compatible cross-pollinating varieties, though even more may be better, because your pollinizers also need cross-pollination.

Rare apple trees don't need other heirloom trees as pollinizers, though some old varieties may be ideal. Any compatible apple tree that produces sufficient viable pollen at the right time will do. Similar or overlapping blooming periods are key, along with consistent heavy blooming and the production of long-lasting pollen. Apple varieties that bloom and produce well one year but lightly the next are not good pollinizer candidates. Flowering crab apple trees, closely related to apples, are often excellent pollinizers. Plant compatible dwarf apple varieties within 20 feet of each other, and compatible semidwarf types within 50 feet. The same distances hold true for crab apples.

Various specialized nurseries, agricultural extension offices and online sources offer helpful charts or checklists to make it easy to identify good pollinizers. For example, Smokehouse can be cross-pollinated by many different apples, including Pink Lady, Honeycrisp and Hampshire Mac. More than 150 possible pollinizers exist for Wolf River apples, but Cripps Pink, Golden Delicious, Granny Smith, Grimes Golden, James Grieve, Roxbury Russet and Spartan are particularly good.

Using flowering crab apples as pollinizers for apple trees is just as effective and often simpler -- particularly if you don't know the name of a rare apple tree you wish to pollinate. It's enough to know when it blooms. Chestnut and Manchurian crab apples are good pollinizers for early to midseason apple bloom, Snowdrift for midseason to late bloom and Indian Summer for late bloom. Washington State University recommends the crab apple cultivars Dolgo, Manchurian, Snowdrift, Whitney and Wickson.