Many gardeners have annuals they replant every year, and the majority buy seedlings or seeds from stores. A fun activity that is very cathartic and so easy to do is to collect the seeds from your own plants to re-sow.
Start with dry seed varieties with no mushy pulp, which are the easiest to collect and store. Think of the annuals you replant yearly, marigolds, salvia, pansy, viola, lettuce, parsley, calendula, sunflowers, poppies, zinnia, sweet pea, and nasturtiums, to name a few.
The trickiest part of the process is to know when to collect the flowers to start processing the seeds. Refine your timing so you don’t collect them too early or too late. Too early and they will not develop into viable seeds and too late they will self-scatter or the insects devour them. Wait for the flower to finish, then brown off and start to shrivel. In some flowers, they will develop a bulge, as with pansy and viola, and this is where the seeds develop. Wait till the bulge has ripened to its full potential, it will start to dry out and shrivel, now is the time to pounce. With plants like marigolds, the flower will brown and dry up, before it has gone too far and let the seeds fall, start collection. With other plants like lettuce, the flower goes from a yellow to a brown to a fluffy ball, now is the time to strike.
Paper bags and a pen are vital, as the seeds won’t sweat and spoil if there is excess moisture. Name the bag as a record of which plant it was and the date collected. Pick off the flower stem and place it in the bag. Hang these bags in a cool, dry place out of direct sunlight, as heat and humidity can shorten the life of the seeds. Some hang the stems in bunches in the laundry and wait until just before the seed drop before they bag them. This leads to the chance you forget to keep an eye on the dried flowers, and you have a floor of seeds.
After two to four weeks of storage, empty the paper bag into a sieve. Using the sieve remove the leaves, petals, and any other rubbish, leaving just the seed. If you are using them soon, store them in an airtight glass jar. If you are keeping them for a long period, you may need to put them in the freezer for up to two days to kill any pests that have made the seed their home. After the freezer then, keep the glass jar in a cool, dry place out of direct sunlight and many use the refrigerator for longevity. A little research may be needed as some seed species do not want to be put into the freezer.
Collecting seeds is no guarantee of the colour being the same as the parent plant, as the cross-pollination by insects affects this. You may get a variety of colours from the seeds collected, which is part of the joy. Seeds do not last forever, so sow them in the next planting season and perhaps with a few purchased punnets if new flower colours are available. Use your seeds for succession planting and for longer flowering season in the garden. When sowing your seeds, use Searles Seed Raising Mix as strong composted soil mixes can burn seeds starting to sprout. Seed Raising Mix is designed to provide high germination performance and healthy growth until transplanting. Once they have developed four leaves, they are seedlings and can tolerate being transplanted and fertilised. Consider swapping your seeds amongst friends for more variety or a lovely handmade gift.