Remember that pollen from corn and cucurbits can easily travel up to 1km!
Plants can cross pollinate with similar varieties of the same species so:
Grow and save seed from one variety of a species each season
Isolate same species by distance or contain them in insect and wind proof enclosures
Plant varieties that will flower at different times
Control pests and diseases during the growing season to avoid the seed borne transfer of viral, fungal and bacterial diseases.
Next year’s plants will only be as good as this year’s seed!
Choose from a large population base. Seed can be saved from individual plants. However, most species are best to have seed saved from a large population base to keep the genetics strong.
Select the best. Always choose the best quality plants, flowers, fruits and vegetables that are true to type. Eliminate any plants that show poor characteristics prior to maturity. Desirable plant qualities to consider are flavour, plant size, harvest time, bolting time, fruiting abundance, yield and pest resistance.
Harvest when the time is right. When the seed pods have dried on the plant or when the fruit or vegetable is fully ripe and well past its edible stage.
CLEANING AND STORING SEED
Remove as much chaff, seed pod and plant material as possible. This can harbour unwanted pests and disease.
Make sure the seed is completely dry or it will rot or get mouldy in storage.
Date and Label all seed packets.
Seed needs heat, light and moisture to germinate so the reverse is best for storage – COOL, DARK and DRY – preferably in an air tight container. Exceptions to this are beans and nasturtiums which prefer to be in breathable bags.
Maintain constant temperature and humidity of seed in storage.
Do not store seed in the freezer. The moisture in stored seed can vary from 1-10%. Higher moisture levels can cause the seed to expand and shatter internally.
Watch out for insects in stored seed. Problem insects include Weevils, Moths, Mites and Trogoderma which are microscopic.
All seed has a shelf life. Seed with a short shelf life should be sown fresh each season including Alliums, Parsnip, Lettuce, Peppers/Chillies (shelf life 1 to 2 years). Other time frames - Carrot 2 years; Beans, Peas and Eggplants 2-3 years; Cucurbits and Tomatoes 3-5 years; Brassica 3-10 years.