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Food Sectors

Seed production

Seed producers grow plants to both supply seed to farmers and crofters, and develop new varieties.

Updated 9 May 2024

Producing seeds

Growing seed crops is similar to growing food crops in terms of both plants needing water and nutrients.

However, you should consider how the crops are pollinated, so their seeds contain the intended genetic material and grow the right kind of plant. Some varieties need multiple growing seasons to grow seed (e.g., biennials like carrots), and it is a good idea to plan ahead how to harvest seeds (see ’Harvesting seeds’).

High rainfall can be challenging for growing seeds in Scotland and you may choose to produce seeds under cover. Read more in the Organic Seed Alliance guide for weather risks in dry-seeded crop production.

There are a variety of online guides on producing different vegetable seeds:

Population size

When planning your seed crops, you plan to sow a large enough population of each variety to retain its complete genetics and prevent inbreeding depression. Plants affected by inbreeding depression lose vigour and fertility due to a small gene pool.

Recommended population sizes vary for each crop, but are a particular consideration for vegetables which usually have less individual plants per land area than, for example, cereals. You should also factor in that some plants may need to be removed due to pests or disease, or not growing true to type (see ’Roguing plants’).

Crop isolation

Before sowing your seed crops, you must ensure that your field layout complies with legal isolation requirements. Isolation distances are a safety measure to decrease cross-pollination, so the seeds grow true to type.

Isolation distances apply to any neighbouring crops of the same or other species that can cross-pollinate, and differ widely depending on the crop species and what category it is certified in (see ’Seed categories’).

To manage isolation, you need to consider sources of pollen – from your own crops, from neighbouring producers’ crops, and from wild plants. You do not need to isolate crops that use the same pollinator.

All crops that can cross-pollinate or otherwise contaminate each other should have at least 2 meters of fallow or a physical barrier between. In addition, some crops have minimum isolation distances for certified seeds:

Beets: 300-1000m, check beet isolation distances.
Cereals: 20-500m, check cereal isolation distances.
Fodder plants: 50-200m, check fodder plant isolation distances.
Oil and fibre plants: 200-1000m, check oil and fibre plant isolation distances.
Vegetables: 300-1000m, check vegetable isolation distances.

SASA can waiver these isolation distances if you have sufficient protections to prevent cross-pollination (see ’Managing crop isolation’), or increase them if deemed necessary.

Managing crop isolation

Following isolation distances might not be practical or possible, particularly if you have a smaller piece of land. There are several techniques to manage this.

Species selection: Selecting only one of two species of crops that do not cross-pollinate with neighbouring plants on/around your land.
Timing: Staggering the planting of crops, so they flower at different times.
Physical barriers: Growing crops inside secured polytunnels or greenhouses, or using isolation cages/tents or blossom bags to restrict the movement of pollen and pollinators.

Sowing seed crops

When sowing seed crops, you must either display the label of the seed lot you use near the field or retain the label and mark it with the field identification number it was sown into, to show to an inspector upon request.

Registering your seed lot

Before sowing your seed crops, you must notify SASA about the seed you are using.

Register your seed lot on MySEEDS or by filling in form SDG 1 and sending it to SASA. You will need your PSO number (see ’registering as a Professional Seed Operator’) and basic information about the seed lot you are using which should be on its label.

You must register your seed lot by the following deadlines, or you cannot get them certified:

	Autumn sown	Spring sown
Cereals	7 November	15 March
Herbage	15 September	15 March
Oil and Fibre	31 August	15 March
Fodder Brassicas	31 August	15 March
Peas and Beans	7 November	15 March

Registering your crops

You must register each crop that you sow, registering each variety sown in a specific field separately.

Register your crops on MySEEDS or by filling in form SDC 2 (cereals only) and sending it to SASA. Fees for crop registrations are paid per each hectare that the crop is farmed.

To register your crop, you need to create a crop identity number (Crop ID) for it. To do this, combine:

The last 2 digits of the harvest year (e.g., 24 if the year was 2024)
Your Professional Seed Operator number
The sheet number of the form

You must register your crops by the following deadlines, otherwise you need to pay a late fee for each hectare or may not get the seeds certified:

	Winter sown	Spring sown
Cereals	31 January	15 April

Field inspections

You must have your seed crops inspected by a licensed crop inspector prior to harvest at least once during the growing season. Inspectors will check whether your varieties are growing true to type, isolation distances and weed contamination.

Certified, C1 and C2 seed crops can be inspected by a licensed inspector or SASA’s official inspector. See the list of licensed crop inspectors in Scotland.
Vegetable crops must be inspected by SASA’s official inspector.

You can make your own arrangements with a licensed inspector and must notify SASA on MySEEDS or by filling in form SDG 2A.

To arrange a field inspection with SASA’s official inspector, request it on MySEEDS or by filling in form SDG 2A. The fee for crop inspections is payable per each hectare inspected.

Crop inspection cards

Once you have registered your crops, SASA will send you crop inspection cards which are given to the inspectors. If you registered crops online, you will print these cards on MySeeds – read guidance on how to print crop inspection cards.

Results

You will receive crop inspection results either from the licensed inspector, if you used one, or directly from SASA. It will tell you if your crops meet the requirements for the certification category (see ’Seed categories’) and give details of any issues, such as lodging.

If your crops do not pass the inspection, they may be downgraded to another category or you may not be able to legally sell seed from them.

You can try to fix the issues identified in the crop inspection report and/or organise a re-inspection, which you will need to pay for again.

Roguing plants

As your seed crop grows, you need to ’rogue’ or remove weeds and individual plants that are not vigorous enough or are not growing true to type.

To get your seeds certified, crops must match the official description of the variety (see ’Certification process’). This is controlled by legally set limits for the number/percentage of plants that are not true to variety within land area/population.

Find limits for varietal purity in the seed marketing regulations (beets, cereals, fodder plants, oil and fibre plants, vegetables) or contact SASA for guidance.

Roguing is done by pulling out unwanted plants before and after flowering, which ensures that their genes do not end up in the final seed lot.

Managing weeds, disease & pests

Your seed lot can be rejected from certification if it has too many weed seeds or disease/pests present. While this can sometimes be fixed after harvest (see ’Harvesting seeds’), you should mitigate the risks during growing and the methods are largely the same as for food crops.

If using herbicides, do not apply glyphosate as this affects seed quality.

Legal limits

Some weeds, pests and disease have been set strict maximum legal limits in certified seed supply, which can be zero:

Beets: none.

Cereals:
- Wild oats and loose smut infection.

Fodder plants:
- Clavibacter michiganensis ssp. insidiosus (bacterial wilt) and Ditylenchus dipsaci (stem and bulb nematode) in alfalfa.

Oil and fibre plants:
- Botryris spp. (gray mould), Ascochyta linicola (foot rot of flax), Colletotrichum lini, Fusarium spp., Sclerotinia sclerotiorum (white mould).
- Pseudomonas syringae pv. glycinea (bacterial blight) and Diaporthe phaseolorum in soy.

Vegetables:
- Leaf blight in celery; leaf and pod spot in peas; lettuce mosaic virus.
- Live mites; bean and pea seed beetles in runner beans, French bean, pea or broad bean.

Notifiable pests and diseases

Some plant pests and diseases are considered a significant risk to Scotland. If you suspect them in your plants, you should contact the Scottish Government’s Horticulture and Marketing Unit for advice.

Pollination

When your crops are flowering, you should ensure they get sufficiently pollinated to produce good-quality seed.

To improve pollination, you must know how the plant breeds (e.g. by self-pollinating or being pollinated from another plant from the same species via an insect or wind). If you have altered these conditions it is necessary to intervene – for example, you need to add pollinators (e.g., blow fly larvae) into isolation cages.

’Pollination and Fertilization’ in Seed Saving Guide, Organic Seed Alliance

Seed production