Can I save the seeds from a pumpkin I purchased from the supermarket?
It’s not a good idea, because cucurbits – think pumpkins, squash, cucumbers and zucchinis – cross-pollinate really easily. This means if your neighbour is growing a different variety than you, they will cross pollinate and the seed you save will almost certainly not grow like its parent. This can occur within a two kilometre radius. There are things you can do to ensure your cucurbits stay true to type, but it means identifying and isolating certain flowers on your plant and carrying out the pollination process yourself. It’s doable, but tricky and you need to know what you’re doing. We’ll look to cover this in more detail in an upcoming issue.
How do I know when to harvest seed?
Peak eating time is generally much earlier than when seeds are ripe to harvest and save. When we deem things like cucumbers and zucchinis ripe to eat, for example, their seeds will be too immature to sometimes even see, let alone germinate. While pumpkins are an exception, more often than not you’ll need to let a plant or fruit pass maturity in order to ripen its seeds. A pea or a bean, for example, you’ll need to let the pod dry on the plant before the seeds are ripe. And for vegetables without obvious seeds like lettuce, spinach and onions, you’ll need to wait for the plant to go to flower which, once dry, will form seeds. When the flowers have matured and are starting to dry out, cut the whole stem off and place it in a paper bag to dry completely.
My mum used to squeeze the seeds of tomatoes she loved onto a piece of power towel. Is this the best way to save tomato seeds?
It’s one way, and it will work, but the preferred way is to squeeze the ripe tomato seeds into a small glass of water and let it sit at room temperature for a few days until a white film forms on top (Pip, Issue 3).
Tomatoes form a coating around their seeds within the fruit which inhibits germination, but by allowing the seeds to ferment a little in the water, you’re breaking down that coating which will improve your germination rate. After a few days, rinse well through a sieve and transfer to a sheet of baking paper until completely dry, before labelling with the variety and date for storage.
Why don’t I see citrus or stone fruit as available seeds to buy? Can I save my own?
The short answer is yes. But the time they will take to develop into a fruiting tree is many years at which point there’s no guarantee that the citrus fruit produced will be as tasty as their parent. Because most stone fruit is selfpollinating, they will generally stay true to type, but you need to remove the seed from inside the shell and subject it to a wintery-like environment in order to stimulate germination. Eight weeks in the fridge will do the trick.
How long will my saved seed remain viable?
Most varieties will remain fresh for up to two years, depending on how well they’ve been stored. But the idea of saving your own seed is to grow or share it for the following year. You’ll get the best results from your saved seed using them from season to season. The other advantage to resowing your saved seeds is they’re already acclimatised to your individual growing conditions, meaning they’ll remember the climate, soil and season in which they matured.
What’s the best way to store my saved seeds?
The three things that will degrade your saved seed are moisture, sunlight and heat. So ensuring your seed is completely dry, and that it’s stored in a cool, dark place is imperative to successful germination the following year. Even when you think your seed is dry, it’s a good idea to store your seed in a paper bag for three or four weeks before moving to a sealed glass jar. To be extra sure, add a handful of uncooked rice to the jar, which will absorb any moisture that may still be present.