Saving seeds from plants you have grown yourself is one of the most satisfying things you can do in the garden, but there are a number of things to take note of before you start collecting. Be aware that many plants will cross-pollinate and therefore will not come true from seed – ie they may have different characteristics from the plant you originally grew and loved.
For example, it is always tempting to save the large seeds from pumpkins and squash, but if you have been growing them alongside courgettes, they are likely to have cross-pollinated and may produce a strange hybrid the following year. In the vegetable garden, the easiest plants to collect from are the likes of peas and tomatoes, which are largely self-pollinating. For all other plants, you should isolate those that you wish to save seeds from by using a mesh cage to exclude pollinating insects. This cannot be done with F1 hybrids, as they are sterile and will not set seed.
In the flower garden, you can experiment more widely (if you do not mind the lottery of flowers not coming true). Even if they do not cross-pollinate, some cultivars may revert to something similar to the original species, so the most reliable flowers to collect from are the species themselves.
In my own garden, I save seed from Digitalis grandiflora, Dianthus carthusianorum, Ammi majus, Cenolophium denudatum, Cerinthe major and Nigella damascena, in addition to poppies and marigolds. I am also collecting seed from several of my dahlias. Some of the simpler, single dahlia species and varieties cross-pollinate readily and it is exciting to see the mixes that arise.
How to save seeds
- Collect seeds on a dry day as soon as the seed heads ripen, usually when the plant turns brown.
- Snip off the seed heads into a paper bag and lay them to dry in a greenhouse or on a warm windowsill.
- Collect seeds from tomatoes and other fruits or berries by mashing them in a fine sieve and then rinsing away the pulp.
After the seeds have dried thoroughly, if you are not sowing immediately, store them in paper packets in an airtight container with silica gel or rice to keep them dry and place them in a fridge to keep cool. If there is any moisture or warmth in the container, the seeds may deteriorate due to fungal disease or rot.
This story originally appears on House & Garden UK.