The simplest way of controlled pollination is using distance isolation (Caging is expensive and hand pollination is labor intensive). Definition: isolation distance is the minimum separation required between tow or more verities of the same species (same genus or family) for the purpose of keeping pure seeds.

Some plants are protected from crossings by just small distance, such as lettuce, eggplant, tomato. Others, such as peppers may need a much larger isolation distance.  Corn, a wind pollinated plant can cross at distances up to 7 Km.

Distance varies from species to species do to difference in flower structure and pollination (wind, insects, self). Isolation recommendations are available on line, but many environmental factors can affect how far or effectively wind or insect can transfer pollen. Consider adjusting recommended isolation distance.

Important thing about distance isolation- every time you double the isolation distance between tow crops that can cross, the amount of cross-pollination decreases by 4.

Factors to be considered: get to know your gardening neighbors and aria

Increased isolation required-

  • Plant population size.
  • Grater number of varieties.
  • Large number of pollinators present.

Decreased isolation permitted-

  • Presence of tall barrier crops or pollen bearing crop.
  • Presence of alternate pollen source for pollinators.
  • Plants planted in blocks rather then long rows.
  • Collection of seeds from center of block planting.
  • Staggered blooming times between plants (time isolation).


Leave a Reply