How to Isolate Heirloom Plants

Heirloom plants preserve unusual traits and qualities for discriminating gardeners. To be an heirloom, varieties need to have been introduced 50 years ago or before and need to breed true from seed. Heirlooms have often been passed down from family to family, or preserved within an ethnic group, a religious order, or a particular tribe. They contain precious genetic material and they link us with history. Interest in preserving heirloom varieties is popular and knowledge of how to avoid cross-breeding with other varieties is needed to get pure seeds.

Measuring tape
Pedometer (optional)
Odometer (optional)
Wooden stakes
Hammer
Baling wire
Wire screening
Spun polyester covering
Wire snips
Scissors
Twist tie
String
Tweezers
Tulle
Organza

Instructions

- 1
  
  Insect pollination needs to be controlled to achieve pure seeds.
  
  Grow plantings at a distance from other varieties to prevent cross-pollination. Measure 20 to 30 feet with a tape measure between stands of lettuce, tomatoes or beans which have self-fertilizing flowers. Measure a distance, using a pedometer or car odometer, of 1/4 to more than 1 mile between plantings of bee-pollinated plants or wind-pollinated plants.
- 2
  Make staggered plantings of varieties to isolate flowering at different times. Plant one batch of seeds three weeks earlier than the other. Pick off late flowers on the first planting and early flowers on the later planting to prevent cross-pollination.
- 3
  Install wooden and wire frames for a row of plants by pounding wooden stakes along the row sides and attaching pieces of baling wire between the stakes over the tops of the plants. Stretch wire screening (to exclude insects) or spun polyester (to exclude pollen in wind-pollinated plants) over the frame, fastening the material at the bottom by throwing dirt on it. Inspect every few days to make sure the covering is secure.
- 4
  Cage individual plants by cutting wire screening with wire snips or spun polyester using scissors that will cover the entire full-grown plant, placing mulch or soil around the bottom to seal the material. Cage or bag individual flowers with tulle or organza cut to fit the flower or cluster of flowers. Tie it around the flower stem with a twist-tie or a piece of string, depending on flower and stem size.
- 5
  
  Queen Anne's lace will interbreed with carrots.
  
  Remove nearby wild plants such as mustard that could interbreed with heirloom varieties of plants in the mustard family, or Queen Anne's Lace, which will interbreed with carrots. Ask nearby gardeners what they are growing so you can take precautions against cross-pollination with their plants.
- 6
  
  Squash flowers are easy to hand-pollinate.
  
  Hand-pollinate flowers to make absolutely sure you know what cross was made. Detach an anther from one flower with tweezers and touch the pollen to the stigma of another flower. Cover the pollinated flowers with organza or tulle bags cut to fit the flower and fastened at the flower stem.

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