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Seed Saving How-To: Part 1

Seed Security

Think ahead to next year, now

No, that’s not a typo— like social security, seed security is about thinking ahead. Like food security, seed security is about resilience, local control and local availability.

With the huge demands this pandemic has put on the stocks of our country’s seed suppliers, seed stocks may be very low for the next growing season. The majority of the seeds Edible Evanston usually distributes for free at our seed swaps—excess seeds companies packed for the previous year and did not sell—might not exist. Disruptions to the economy, transport and supply chains may shift seed-growers to food growing. Climate change shifts and disrupts seed-crop success. And seeds grown in other climates and other conditions might not thrive here, in Evanston.

So what can we do about all that?

We can plan now to save our own seeds for our use and to share in the community. (Edible Evanston will collect seeds starting in the next few weeks.) But it does take at least a little planning! In this article we will cover some of the basics to get started. In future articles we will go over details of the how and when and storage tips.

The basics

Here’s the summary: avoid F1 hybrids, start with self-pollinators, be aware of isolation requirements, leave a couple of plants to fully mature for seed, and have those be the best ones you have—the individuals that are most delicious, most disease resistant and whatever other characteristics for which you might wish to select. 

If all that makes total sense, refer to this chart:

Crop-Specific Seed Saving Guide from Seed Savers

And skip most of this article. Otherwise, read on!

Kingdom Phylum Family Order Genus Species

I remember this from Junior High, but why do I need to know this as a seed saver? All members within a species can cross with each other, so buttercup squash and banana squash, both members of the maxima species, can freely cross-pollinate. Likewise, summer squash and most pumpkins can cross-pollinate, because they are in the pepo species. This means you can’t predict that the seeds will grow the same vegetable that you just harvested unless you follow some of the steps below.So why do I need to know this as a seed saver? All members within a species can cross with each other, so buttercup squash and banana squash, both members of the maxima species, can freely cross-pollinate. Likewise, summer squash and most pumpkins can cross-pollinate, because they are in the pepo species. 

F1 Hybrids, Open Pollination, and Isolation

Horticultural scientists have created amazing plants with superior characteristics. Sometimes that’s done by creating an F1 hybrid—seed which always has to be carefully crossed between two varieties of a species to create a third type of plant which will—and this is the critical part—NOT breed true in the next generation. (That generation is known as an F2.) If you save seed from an F1 hybrid you will likely be very disappointed with the results when you plant that seed the next year. It might produce something desirable, but it most certainly will not produce the variety—like a Sungold F1 tomato—that you so liked.

Keeping track of what varieties you planted and if they are open pollinated or F1 hybrids is crucial to seed saving success. (And part of the reason saving supermarket seeds is such a crap shoot.)  Write it down!

Another reason saving seeds from what you buy at the supermarket, or the farm stand, or the farmers market can backfire is outcrossing, as mentioned below. While I’m always railing against monocrops, saving seeds from a farm known for the diversity of a single type of vegetable species—like winter squash—is a plan for a voyage into the unknown and sometimes bizarre. Squash are particularly promiscuous—crossing with everyone in their neighborhood as pollen-laden squash bees and bumblebee fly from flower to flower over long distances. And this is true both within your yard and in your suburban neighborhood. (With some plant species, it’s also true that they may cross with the weeds in your neighborhood!) To prevent this, seed savers have come up with isolation distances for varieties of the same species (see the chart linked above). Diversity is fine between species when saving seeds.

You must know if the plants you are growing for seed are likely to cross with other plants nearby. For simplicity, start with those which are usually self-pollinating—beans, tomatoes, peppers, lettuce are great examples. They require very short isolation distances and are most likely to breed true even without isolation. Have a favorite tomato you want to save—perhaps grow that off on its own, instead of cheek-by-jowl in a row with all the other varieties.

How does it pollinate?

Buzzzzzz! There is so much interest in pollinating insects, bats and birds, and rightly so. But not all plants depend upon insects for pollination—some plants, like corn always, and beans often, are wind pollinated—not requiring an insect to dislodge the pollen and move it to the female pistil. How and where is the pollen moving to fertilize the plant lets you know much about the seed.

Self-pollinating pollinating plants are capable of creating viable seed with a single plant fertilizing itself, also known as inbreeding. Those which depend on out-crossing require another plant in the same species.

Just because self-pollinating plants don’t require another plant, that does not mean they will never cross with another plant. So what they might cross with becomes critical.

Annuals and Biennials (and Perennials)

Some plants set seed in their first year (and then die, or at least don’t survive our winters), some set seed only in their second year and then die, and some live indefinitely.

To reliably get seed from chard, beets, kale, parsley and many other garden crops, you need to successfully overwinter the plant and let it flower and go to seed in year two. To get seed from cilantro, arugula, dill, beans and peas and other annuals does not require that much time.

Seed maturity

When is the plant going to produce viable seed? At the same time as the food crop, or later?

Tomatoes and (red) peppers are wonderful for seed saving, since they are generally self-pollinating and they provide seed at the same time as the fruit is ripe for eating. Peas and beans are a little harder—they are only ready at the dry, fully mature stage. So delicate green snap beans won’t have mature seeds, nor will snow peas for the stir-fry or salad. But if you grow for dry beans, then that’s the same stage. We know lettuce is not very palatable when it begins to bolt, but to get seed one needs to let it fully bolt, flower, and then create hundreds (thousands??) of little seeds with fluffy parachutes.

So one lettuce plant, left to fully mature, can provide you and a lot of community members with plenty of seed, but it does require letting it stay in the garden and take space for much longer than if you just wanted it for food. Leaving a few beans to mature—and leaving them early enough that they have time to fully ripen and dry—will give you enough to plant the next year. If you want to share, you need to leave a few dozen. A couple of tomatoes you seed for a recipe anyway can provide enough seed for you and dozens of others to grow that variety next year.

Seed Life and Viability

Properly stored seeds can be viable for a long time, but how long depends on the type of plant they came from. While we will get to storage tips later, seeds should be kept cool, dry and dark. Older seeds are not doomed to failure, but usually have a lower germination rate and a slower germination time. Basically, they get less predictable.

Waterlilies have germinated from seeds more than 1000 years old. Beans have germinated from seeds more than 150 years old. I got 100% germination this year from 8-year old Sungold tomato seed. I have had great luck with 10-year old chard seed. I have had terrible results with onions just two years old. However, the guidelines here are useful guides: Seed Saving Chart is on our website and a more comprehensive option is High Mowing’s Seed Viability Chart

So, if you have excess seeds and they are likely to be viable next year, but you don’t want them, please donate the rest of your packet to Edible Evanston!