How To Save Seed - Seed Saving Principles

When Saving Seeds Always Save The Best Seed From The Best Plants At The Best Time.

Table of Contents

Seed Saving Principles- HOW TO SAVE SEED

Why save seed?

There are two reasons to save seeds. The first of the Seed Saving Principles is to preserve seed that is true to type and can be grown year after year with the crops being very similar each year.

The second reason is to breed new varieties that have higher yields, better disease or pest resilience, drought tolerance etc. This requires specialist knowledge and shouldnt be undertaken lightly.

The advice in this article assumes that seed is being saved for the firs treason, to preserve existing seed strains for future use.

Beware genetic drift

Within a batch of plants there will always be a range of characteristics, eg tall peas or short peas. So if we are trying to save seed from a variety we know should be tall we shouldn’t take seed from the short ones. If we do, the chances are that the seed will produce more short peas and if we repeat this for a few generations we will end up with a new variety that is predominately short.

The varieties we save seed from should be open pollinated. That way we will always get seed that will breed true to its parents. Non open pollinated varieties are extremely likely to be cross pollinated and will not breed true.

Genetic drift allows us to slowly select for changing conditions without breeding new varieties. But in most cases we wish to maintain a variety. We can start to select for new characteristics if we wish but it should be part of a planned breeding programme. If it isn’t, we might change several characteristics at once. For example we might decide to select short peas but in doing so we might lose the sweetness or tenderness of the pea. Ending up with something of the right height that is inedible isn’t what we want.

The plants we save seed from must be typical of their variety. Don’t save seeds from those that have different shaped leaves, different colour flowers,different heights etc for that variety as they are not typical.

Any plants that bolt much earlier than the majority should be destroyed. We don’t want seed from early bolters as they are likely to breed more plants that will bolt early.

Seed Saving Principles- the best way to save seed depends on the species.

Hand Roguing

Hand roguing a crop is the process where the plants are regularly checked and any that are atypical, diseased or have pests, are removed.

Only select seed from the best plants in a batch. For example, you might grow 10-20 plants for seed but only select seed from the best few.

Where the seed is from a plant that is normally grown for fruit only take seed from those that have fruit that is typical of the variety.

Beware cross pollination – isolation distances for viable seed production

Ensure that the seed saved has not cross pollinated with unrelated plants. Some plants are self fertile and rarely cross. Eg tomatoes. But others are easily crossed with other varieties and even species. Eg brassicas, are very promiscuous and cross readily. Unless you take precautions you could find your cabbage has been crossed with a kale, oil seed rape or similar and will be a totally different plant when grown. It’ll not be a cabbage, kale or oli seed rape!

Brassica growers usually grow seed crops at least a 1000 yards from other brassica crops. That is really difficult to do in many countries where either brassica crops and related weed species are growing nearby. One way to overcome the problem is to grow the seed crop in a netted area so that pollinators can’t cross fertilise the crops. Other crops may need the flowers to be protected inside “socks” that prevent cross pollination.

In many cases, because of the risk of cross pollination, it makes sense to only grow one plant variety for seed production at a time.

Where crops are wind pollinated the pollen can often travel long distances on the wind. One way to help protect the seed is to grow a large block of the crop and only select seed from those in the middle that have been shielded from the majority of the wind blown pollen.

Where the plant grows a dense head before flowering, e.g. some lettuce and cabbage, it may be necessary to cut away part of the head to allow the flower head to emerge.

Grow enough plants – minimum plant populations

Grow enough plants to allow for hand roguing, wastage and to select enough good plants that are typical of the variety. It’s always tempting to harvest the best crops to eat, but resist this and save seed from the best. How many p;lants are needed to produce seed will vary from species to species. The more the better, because if you only grow 2-3 plants they may not be typical of the variety and/or get a problem which means your seed collecting opportunities are greatly reduced.

Harvest at the correct time

Only mature seed should be harvested. The appropriate time varies from plant type to plant type. For example lettuce should be harvested when the seeds start to develop their little downy parachute and it starts to shed. A few days earlier is often ok but the seed matures over a period of time so if this guide is followed you will always get some seed.

If seed is left too long before harvesting it will shed and be lost. Establishing the right time is something we all learn from experience.

The seed from fruit such as cucumbers, gourds/marrows/courgettes, peppers etc need to be “ripe” before we harvest seed. Immature seed will not germinate and grow into plants.

Daikon is a Traditional Japanese Vegetable

Some fruit need to “cure” a while after harvesting, before we take seed from them. This includes marrows, gourds, squashes and related species.

Experience will show you the correct stage of maturity and/or curing you need to reach before harvesting seed.

Germination testing of fresh seed

New seeds should readily germinate. So it’s a good idea to test germinate a few seeds to ensure we have collected viable seeds.

Take a sample of 10-30 seeds, the exact number depends on the batch size, and germinate them on moist paper towels or similar. Place the towels and seed in a container and germinate at the most suitable temperature and put in a dark place. Start checking for germination after a suitable time depending on the species.

Working in multiples of ten seeds makes it easier to calculate germination percentages.