Another great aspect of harvest season is that it’s the time of year when most plants go to seed, thus ensuring a strong new crop for the following spring. Those of you with food gardens have probably noticed the metamorphosis that your plants are going through right now, but unless you have experience with harvesting and keeping seeds, you probably don’t quite know how to go about doing so. Good news, then! This is the first in a 2-part piece on how to harvest those little nuggets of potential so you can sow them once springtime rolls around once again.
With so much dirt coming out about Monsanto’s unethical practices and the prevalence of GMO plants, it’s become far more important to save organic and heirloom seeds to preserve diversity and health in our food plants. If you’ve planted organic herbs/veggies in your own garden, it’s great to harvest seeds for the next planting season. But if you’re uncertain whether they’re organic or not, you might want to hold off on doing so—there’s a good chance that any non-organic seeds you harvest won’t be viable, and may have genetic modifications we don’t want to propagate.
We’ll be focusing primarily on small seeds for the intro here: namely herbs, tomatoes, and berries.
If you’ve ever planted herbs from seed (either culinary or medicinal), you’ll remember how teensy those they are: basil seeds are around 0.5mm each, for example, and most other herb seeds are comparable size to that. If you try to pluck the pips from your culinary or medicinal plants while they’re out in the garden, you’re likely to lose half of them to the soil below. The best way to collect these seeds is in a simple brown paper bag.
If you’ve decided to harvest your own seeds, be sure to let a portion of your plant stock go to seed, instead of plucking all the flowers from them; those buds will dry up, and the pips will form inside them as they do. Let these dry out as much as possible on the plant itself out in the sunshine, but keep an eye on weather forecast and feel free to harvest them early in case of major storms brewing.
When the seed heads are dry enough to be plucked, place a small paper lunch bag over the plant and secure it several inches down the stalk with a twist-tie. Cut the plant with a knife or scissors a few inches below that, tie a string around the twist, and hang the bag upside-down in a cool, dry place for about a week; this will give the plant even more time to dry out, and the seed casings tend to pop open as they dry and shrink.
After a week (or two) has passed, take the bag down and shake it fairly vigorously—this will help to free the seeds from their casings, and they’ll collect at the bottom of the paper sack.
Most people who are new to home/urban gardening start out with a couple of tomato plants—whether little cherry tomatoes in pots on a balcony, or several varieties scattered through their garden space. Saving tomato seeds is a slightly more involved process, as they require a bit of fermentation to break down the delicate membrane around each seed so they’re open, fertile, and ready to plant in the spring.
Scrape out the seeds of a ripe tomato, and set them aside in a dish. Try to harvest only one variety of tomato at a time so you don’t accidentally mix your batches. Put the collected seeds into a very fine sieve, and run them under running water, rubbing them very gently to get as much of the pulp off as possible. Once cleaned off, put the seeds in a clean jar, add about a cup of room temperature water, and seal with the jar’s lid. Keep the jar in a cool, dark cupboard for a few days, and just give it a bit of a swirl a couple of times a day. In a little less than a week, you should see frothy bubbles forming in the jar, and most of the seeds settled at the bottom of it: these are the viable ones, so discard any of the floaters, and tip the bottom-dwelling seeds back into that sieve, give them a good rinse, and then spread them out on paper towel or a very fine mesh screen (like an old window screen) to dry for a couple of days.
The method of saving berry seeds is very similar to that of tomatoes, only without the fermentation process. For species like currants, raspberries and blackberries, just mash the overripe fruit around in a metal sieve to loosen it all up, rinse under running water, and allow to dry on paper, paper towel, or a mesh screen. To save the tiny seeds of certain berries (mulberries, blueberries), it’s actually better to freeze or dehydrate some berries whole and then plant them in the spring: as the fruits decompose, they’ll nourish the seeds held within them.
If you’ve decided to go ahead and dry some seeds, you’ll need to store them safely until the next planting season. The two greatest enemies of safe seed-saving are high temperatures and high moisture, so if you store your seeds in a place that tends to get damp, or where the temperature and humidity fluctuate dramatically, it’s more than likely that the seeds will lose their ability to germinate. Ideally, you’ll want to keep your seeds in paper envelopes that have their variety and date harvested written on them, and store those inside closed glass jars. Keep these in a dry place that stays at a pretty even temperature, and you should have viable seeds aplenty next season.
Note: If you can get your friends and neighbors to save seeds from their gardens, you can organize a seed-trading party in the spring. This will give you all a chance to get your plants cross-pollinated with other strains, and you’ll be able to try out different varieties to see what grows best in the space that you have. You’ll also be able to see which varieties you like the most!
Stay-tuned for Seed-Saving part 2, in which we’ll focus on saving larger seeds: gourds, melons, beans, and grains.