Germination test


If you have a stash of seeds from previous years but aren't sure if they're still good, try doing a simple germination test. Some seeds keep well for years while others have a very short shelf life. For example, lettuce, cucumber and endive can keep for 5 - 6 years while parsnips, parsley and some onions barely last a year.

Here's how to do a simple germination test:

  1. Spread 10 or more seeds on a moist (but not soppy) paper towel, fold it over once or twice and then place that in a plastic bag and seal.
  2. Keep in a warm place and check the seeds every few days. Read the seed packet to see how many days it takes to germinate your particular plant.
  3. After the required number of days, count the number of sprouted seeds and divide by the total number of seeds to get a percentage.
Even if you have a low germination percentage, the seeds can be used. Let's say your percentage is 60%. Go ahead and use them but sow the seeds a little more thickly in your garden.  Thin any extras once the seedlings are up. Please know that it is critical to thin the seedlings if you overseed and you want your plants to be robust and healthy in the long term.

If you're testing seeds like tomatoes or peppers and don't want to waste the test sprouts, carefully cut the paper towel around the sprout (avoid snipping the root). Then plant it into a container of potting soil where it can continue to grow.

Another top tip: When buying new seeds, mark the year of purchase on the package.