Seeds not germinating?

Seeds lose their vigour over time and, they can deteriorate more quickly than they should if storage temperatures or moisture levels have been unsuitable. If a batch of seed has not germinated well I do a germination test on some of the seed to see if it’s worthwhile trying another crop.
All I need for this is a wide mouthed screw-top jar, a saucer, and some cotton wool.
I place the cotton wool in the centre of the saucer, and add enough water to wet it thoroughly – but not enough to allow it to float in the water. Seeds absorb a lot of water during germination, and inadequate moisture alone can cause germination failure. I then check that the cotton wool is covered by the inverted jar.
Then I sprinkle a sample of the seed from the suspect batch onto the cotton wool. If the seeds are large, such as corn or cucurbit seed, I use the blunt end of a pencil to press the seed firmly onto the surface of the cotton wool, so that they have good access to moisture. This is unnecessary with small seed.
When I place the jar over the cotton wool I have a miniature glasshouse. Most seeds require dark for germination; and I place the mini glasshouse in a dark cupboard that is not opened frequently. I check the jar every three days for signs of activity. To test if the cotton wool is still moist, I lift the jar and check that the cotton wool is still moist. If necessary, I add a few drops before replacing the jar.
Some vegetables such as most lettuces, cape gooseberry, seakale, shiso and tomatillo, and some herbs and gazanias require light for good germination. For these seeds the jar can be kept in a well-lit room out of direct sunlight. Seed packets will indicate the best conditions for that species’ germination.
Most common varieties of vegetable seeds will show activity in a fortnight or so, but some, including capsicum, carrot, celery, eggplant and parsley can require a month for germination to occur.
If the majority of the seeds show signs of germination, the problem is more likely to be the growing mixture, lack of adequate moisture, or unsuitable soil or growing mix temperatures. If germination is poor or the seeds don’t germinate at all, and the seed was purchased recently, the supplier should be contacted to replace the seed.
To reduce problems with seeds, packets should be kept in a cool stable environment where they are protected from moisture and pests. A metal biscuit tin makes a suitable storage container if the tin is kept in a cupboard in the centre of the house where temperature fluctuations are minimal.