How to test seed viability
Like food, seeds have a shelf life. Find out how to test whether yours are 'viable' in our guide.
Sowing seed that is old is a bit of a gamble. It might germinate well, but it might not. Over time, seed viability decreases, and different seeds have different storage times.
To take the guesswork out of sowing old seed, do a simple viability test. It will tell you if the seed is worth sowing at all, and how much to sow. If only a small percentage of seeds germinate, you'll need to sow a greater number to ensure a decent crop.
Follow our 14-day test to check whether your old seed is worth sowing, below.
You Will Need
- Seeds
- Kitchen towel
- Plate
- Cling film
Step 1
Lay a piece of damp kitchen towel on a plate, then sprinkle a sample of your old seed in individual rows to aid identification.
Step 2
Cover the plate with clingfilm and keep it in a warm place indoors. Make sure the towel stays moist and check regularly for signs of germination, noting the date when shoots appear.
Step 3
Germination times vary between veg, but after two weeks most viable seed should have sprouted. Count how many have germinated – if it's about half, then you've got 50 per cent viability. The lower the percentage, the more seed you'll need to sow to get a decent crop.