How to Collect and Store Heirloom Vegetable Seeds
- In This Quick Guide:
- Before You Begin
- Wet Process
- Dry Process
- Storing Seed
Collecting and storing seeds is the most important aspect of raising your own heirloom vegetables. Whether it’s cucumbers, peas, tomatoes, or carrots, this guide will teach you how to collect and store the seeds you’ll use for next year’s harvest—and the seeds that you can share with friends and family.
Before You Begin
There are a few things to keep in mind when gathering your future crops:
- Only mature seeds will end up viable, so don’t try to collect seeds from young fruits.
- Don’t keep the seeds from a plant that has a disease. Not only could the disease remain on the seed, but the mother plant may be particularly susceptible to it, and you could be planting the same genetics for next year. Saving and planting diseased seed can also weaken the future line of the heirloom variety.
- Save seeds from several plants of the same variety to keep the gene pool strong.
- Seeds don’t keep indefinitely. Every few years (depending on the species), the seeds need to be planted, the crop grown out, and the seeds collected once again.
There are two methods used to collect seeds from vegetables: the wet process and the dry process.
Wet Process
This technique is for collecting seeds from fleshy, pulpy fruits like tomatoes and cucumbers. Here’s how you do it:
- Squeeze or scoop the insides of the vegetable into a container and leave it to ferment. (The process may look unsavory, but fermenting actually encourages seed germination later and kills some diseases.) In three to five days, the mixture will have completely fermented and mold will have formed over the mix. This is just fine.
- Take a large spoon and scoop as much of the mold-fungus off of the top of the seeds as you can. Add a lot of water into the container and swish everything around.
- Let everything settle in the container for a moment; you’ll see that some of the seeds float and some of the seeds sink. It’s the “sinkers” that are the keepers; these are the viable seeds.
- Pour off the rest of the debris and most of the water, being careful to keep the sinkers. Put the sinkers in a small-holed strainer or a screen-type strainer for rinsing. (Make be sure that the holes are smaller than the seeds you’re cleaning!) This eliminates most of the mold and bacteria.
- Once the seeds are thoroughly rinsed, it’s time to dry. Place the seeds in a netted bag and hang them in an airy place to dry. You can also put them on a tray or in a container on the counter or a shady windowsill. Stir the seeds once in a while to give them a chance to dry evenly all over. Don’t use your oven or direct sun to dry your heirloom seeds. The heat from both can damage them. If you’d like to speed up the drying process, try using a ceiling fan.
Note: Seeds collected from the center of vegetables have a lot of moisture in them and need more time for drying than those gathered from pods. Although these seeds should be dried as quickly as possible, be careful not to dry them so fast as within a week, because if you do, they’ll shrink and crack.
Dry Process
This technique is used for those veggies whose seeds are held inside pods, husks, or any other dry casing like peas, beans, and carrots. Here’s how you do it:
- Unless wet weather is in the forecast, these types of seeds can be dried right on the plants. As the seeds begin to look mature, secure paper bags over the seed heads and attach them to the stems of the plants. This will catch any seeds that ripen early. The stuff you’re left with after collecting these seeds is actually a mixture of seeds and what’s called “chaff”—pod or husk coverings and other debris that fall in with the seeds.
- Next, separate the seeds from the coverings and chaff (this is called “threshing”). Put the collected seeds into a bag, pillowcase, or small sack, secure the ends, and roll it around, lightly crushing the contents a bit. Don’t get all macho—you don’t want to damage the seeds. For the tinier ones, you can use a flat board to gently press on the seeds to loosen the chaff.
- Now you need to get the loosened chaff off your seeds (this is called “winnowing”). Place the seeds in a bowl and shake the bowl around a bit. Most of the chaff is lighter than the seeds and it’ll rise to the top. Blow gently into the seeds to remove the lighter-weight chaff. Repeat this process until all (or most) of the chaff is gone. Another option is to use a screen or sifter where the holes are smaller than the chaff. You can simply sift them apart. The size of the sifter holes will depend on the size of the seeds and the chaff.
Tip: You may want to be sure you have a large sheet underneath your workspace so if any seeds are blown with the debris, you can retrieve them. Or work outdoors on a day that’s not too windy. (If you do use a sheet, be sure all previous seeds are removed before you do any winnowing with other varieties.)
Storing Seed
Seeds need to be stored in an atmosphere free of moisture with as little temperature fluctuation as possible. You don’t want the combination of the temperature and the humidity levels to exceed 100. For example, with a storage temperature of 60°F, the humidity should not exceed 40 percent.
The simplest way to store seeds is in individual envelopes, which should be placed as a group inside an airtight container for extra protection.
The best place to store your seed containers is somewhere cool, dark, and dry, such as the refrigerator. If the refrigerator isn’t convenient for you, consider floor-level areas such as an unused room, cellar, or mudroom. Even if you’re using the refrigerator as your seed storage facility, you’ll want to have a backup plan (like a cool garage or cellar) in case of a power failure. If your power is out for an extended period of time, it could mean a total seed loss!
From The Complete Idiot’s Guide to Heirloom Vegetables by Chris McLaughlin
