The need to preserve genetic diversity came through as a major theme in Joanne Jellett’s presentation at the September meeting of Chester Garden Club. As a master gardener with experience in cross-breeding lilies, Joanne pointed out that seeds from hybrids do not produce the same quality or quantity of seeds as those from the original plants.  Hybrids are cultivars that have been cloned to produce particular traits that create a new plant with hybrid vigor, but the in-breeding tends to render the male plant sterile.  As a result, genetic engineering is required to make it fertile again.

Unlike natural heritage plants, these cultivars lack an adequate supply of seeds and berries to feed birds and insects, so gardeners who rely solely on the hybrids found at most nurseries will inadvertently be reducing the food supply for pollinators and other species that visit their gardens.  Joanne noted that a lack of genetic diversity impoverishes the natural world, and she encouraged members of the club to be aware of the need to grow heritage plants wherever possible, and to begin collecting seeds of those plants so as to preserve them for future generations as their mothers and grandmothers did in years past.

Much of her discussion on seed collections was focused on vegetables. She indicated that self-pollinating plants such as peas, beans, lettuce and tomatoes were good candidates for seed selection because the seeds would produce plants like the original variety. Many other plants are subject to cross-pollination, producing seeds that are therefore not true to the original. The  next generation of plants from those seeds would display variation in colour and other characteristics from that of the original.

It is important to wait until seeds have matured on the plant before harvesting.  As a rule of thumb, seeds turn from white to cream or brown when ripe for picking.  Individual seeds should be allowed to dry, spread out on paper towels laid over a screen. Experienced seed collectors do not place wet seeds on newspaper to dry because the seeds will stick to the paper and are then difficult to lift off.  Seeds that are still attached to a flower stalk should be placed in an open paper bag to dry.  Once seeds are dry they can be stored in a closed paper bag or in a jar along with a few grains of rice that act as a drying agent.  Joanne cautioned against storing seeds in a plastic bag because of the danger that mould and pathogens would grow in such an environment.

Some plants, like Brussels sprouts and other cruciferous vegetables, produce seeds that must be pasteurized before storing.  This can be done by immersing the seeds in water at a temperature of 48º C for about 15 to 25 minutes. That treatment kills all pathogens.

The “wet method” of saving seeds involves a messy method that does in fact produce good results. After scooping out the seeds, place the mushy mix in a glass container with water. Stir it every day and allow the fermentation to kill viruses. The viable seeds descend to the bottom of the jar and the mushy mix on top can then be thrown away.  The seeds can then be rinsed off, dried and stored in the usual way.

When storing any seeds, it is useful to remove any related chaff that could attract fungus or mould. To get rid of the tiny insects that sometimes are found on seeds or seed pods, place the seeds in a freezer for a few days before storing.  Two last tips from Joanne for gardeners to consider next spring:  the need to remember vernalization – the process whereby many seeds need to experience a cold spell before they will germinate, and scarification – the technique of grating or nicking the protective “armour” of the seed coat to enable the living embryo within to emerge.