Have you ever found some old packets of seed and wondered if the plants would still grow? The germination rate of old seed is variable; some vegetable seeds, such as cabbage, beans and onions, can be sown for several years, while parsnips will have poor germination by the second season. And so it is with flowers – cleome and larkspur seed can be kept, while primula and meconopsis seed is best used fresh from the mother plant.
To check if seed is viable, moisten one square of paper towel in warm water. Squeeze out the excess moisture and fold in half. Place seeds on half of the paper towel. If the seeds are large, count out 10 seeds; if small, just sprinkle a few. Fold the other half of the paper towel over the seeds, creating a small package of seeds. Now pop the package into a plastic bag, close it and place it on top of the refrigerator.
Do a daily check for germination from day two onward. Just open the plastic bag and lift one corner of the paper towel and peek inside. When (or if) germination occurs, the little sprouts will be quite visible. Obviously, if none or only the odd seed germinates, the remaining seeds should be discarded. A germination rate of 45 to 50 per cent is okay, but would indicate that more seeds will need to be planted to achieve the required number of plants.
It is possible to lift the germinated seeds from the paper towel with tweezers. Place the sprouted seeds in containers filled with good quality potting soil, already dampened with warm water, then cover lightly with additional soil. The seeds will thrive quite nicely, provided the growing sprout was not damaged during the transfer.