INTRODUCTION TO
HEIRLOOM GARDENING AND SEED SAVING
I have realized that there are some things that you need to
be introduced to before you can plan your heirloom gardens and select your
seeds. We will be going into these
concepts in depth in the classes, but I’d like to give you some basic information
now to help you plan your garden and make your seed selection.
Here is a quick guide to the difficulty of saving seeds from
various species.
Easier species:
Peas, tomatoes, beans, lettuce, tomatillos, squash, eggplant and potato(no pollination)
More difficult species: beets, spinach, cucumber,
onion, pepper and turnip.
Most difficult species: watermelon, carrots, melons and
corn. Melons need to be hand pollinated
and it is very difficult to distinguish between the male and female
blossoms. Corn needs to be planted in
volume of at least 100 plants. You need
to collect pollen from 50 plants and use it to pollinate 50 other plants, this
prevents inbreeding depression.
For many plants, you
will not be able to save any pure seeds if you plant multiple varieties of the
same species. If you do, you must be
able to isolate these varieties from each other by one of the methods described
later. If you would like to change your
seed requests, please let me know.
The difference between heirloom and hybrid seeds.
Heirloom seeds have reproduced plants identical to their
parent for many generations, and if properly protected, will continue to do so
indefinitely. Varieties are protected
and reproduced year after year. You can
save and plant these seeds every year and get the same produce.
Hybrid seeds are from plants that experienced cross
pollination either purposely or naturally.
Hybrid seeds will produce plants that are different from their
parent. You can only reproduce the same
hybrid by crossing the same identical original plants. You cannot plant the seeds of hybrids and get
a plant that resembles its parent. Most
commercial hybrid seeds restrict you from saving seeds, or have sterilized the
seeds, so you have to buy seeds every year.
Pollination
Heirloom seed saving requires extra effort in order to
prevent cross pollination. In order to
understand how to prevent this, an understanding of how plant pollination works
is required.
There are three ways that pollination occurs, Wind Pollination,
Insect Pollination and Self Pollination.
Wind Pollination
Pollen is dispersed by the wind. The purpose of the wind is to shake the
pollen from the tassel onto the silk, but pollen is very light and can travel
several miles on the wind, crossing it with other gardens. It is difficult to isolate wind pollinated
plants by distance, and more difficult methods must be used. Corn, Spinach and Beets are in this category.
Insect Pollination
Many plants produce both male and female blossoms on the
same plant. The male blossom is on the end of a long straight stem and has an
Anther that produces pollen ready to be picked up when the blossom opens. The female blossom is on the end of a
miniature fruit and has a Stigma that receives the pollen and the fruit or
vegetable matures. Insects such as bees,
transfer the pollen from the Anther to the Stigma. These varieties must be hand pollinated or
isolated to keep the variety pure.
Squash is familiar insect pollinator.
Self Pollination
These plants have functional male and female blossom parts
within the same blossom. Pollination
occurs within the blossom. Some beans
are pollinated within the blossom and it never opens, eliminating the possibility
for cross pollination. Others, such as
peppers, self pollinate, but then the blossom opens which allows cross
pollination by insects.
METHODS FOR MAINTAINING
PURE VARIETIES
Please note that you do not have to have all of the produce
from a plant pure, only enough of them to save the seeds. The produce that is pure and is for seed
saving must be marked clearly.
There are 4 methods that are used to keep seed pure.
Distance Isolation
The distance isolated must be large enough to prevent
contamination by insect or wind blown pollination. This distance will vary from species to
species and is referred to as the “isolation distance.” You do not want to grow a different variety
of a species in the same spot, seed from the previous variety will have dropped
and will grow and cross with your current variety.
Time Isolation
Annual Varieties that cannot be isolated by distance can
sometimes be isolated by time. This can
be done by planting the first variety as early as possible. Then the first crop begins to flower, sow the
second variety. Time isolation will only
work if the first crop sets all of its seeds before the second crop reaches the
flowering stage.
Mechanical Isolation
This can include bagging, caging or alternate day caging.
Hand Pollination
This technique is used mainly for vegetables that are insect
pollinated but can also be used for some crops that are wind pollinated. This involves transferring uncontaminated
pollen from a male blossom onto the receptive stigma of the female blossom
which has also been protected from contamination. After the female blossom has been pollinated
by hand, it must be protected from contamination.
