Unveiling the Secret to Moisture: the Life Of a Seed

By Tom Seest

How Does a Seed Stay Hydrated?

At SeedOilNews, we help people who are curious about seed oil by collating information and news about seed oils.

Most vegetable and flower seeds will last several years with proper storage conditions; however, for maximum longevity they should be dried down to under 8 percent moisture content for best results.
When purchasing seeds, look for heirloom or open-pollinated varieties adapted to your growing zone. Consider saving seeds from healthy plants yourself to save money and ensure a variety of healthy, adapted varieties! Creating your own seed bank could save money and ensure a constant source of healthy, adapted varieties!

How Does a Seed Stay Hydrated?

How Does a Seed Stay Hydrated?

How Does Humidity Affect Seed Moisture?

Seeds require airflow in order to thrive, which is why they must be stored in an ideal climate that’s both cool and dark; this allows them to remain dormant until ready for planting or activation.
Refrigerators offer ideal conditions, with temperatures staying relatively consistent and low. However, opening and closing the fridge door too frequently could lead to moisture build-up inside containers storing seeds; to address this, add silica gel or powdered milk as desiccant to their containers as a preventive measure.
Once the seeds are dry, it’s essential that they remain as moisture-free as possible so mold or mildew won’t form on them. Some experts advise waiting until signs of mold start emerging while others use fruit flies as an indicator. It could take several days up to months before all the chaff that makes up most of your seed has fully dried out.

How Does Humidity Affect Seed Moisture?

How Does Humidity Affect Seed Moisture?

How Does Humidity Impact Seed Germination?

Humidity controls the rate at which moisture evaporates during drying. This is essential, as seeds that haven’t dried completely before storage will deteriorate rapidly and even sprout, rendering replanting impossible and jeopardizing crop quality. To best preserve seed quality and yields for replanting purposes, keep dormant seeds stored somewhere cool, dark and temperature and humidity controlled until ready for sowing; keeping seeds dormant allows time for proper climate and humidity controls to return their vitality and sow when needed – simply keeping dormant until ready. Temperature and humidity must also remain controlled to protect their quality when sowing.
Seeds are hygroscopic, drawing moisture in from their surroundings while simultaneously giving off some. This process determines their moisture content, which in turn influences many other aspects of metabolism such as fungal issues, heating or weakening. Therefore, it is critical that immediately following harvesting you measure its moisture level and dry it to low levels for safe storage.
There are various methods for drying seeds. Natural atmospheric air may be used, while others utilize heated or unheated air forced mechanically through driers, depending on size, operating conditions and seed type/moisture content being dried. Power requirements to run these fans vary widely based on size, operating conditions and kind/moisture content being dried – typically controlled via relay to activate when relative humidity levels fall below a specified level in storage areas.
Vacuum drying is another method used to dry seeds. Similar to dehumidified air, vacuum drying works by lowering vapor pressure in ambient air and drawing off seed moisture more readily into surrounding air for evaporation. Unfortunately, vacuum drying can be slow, expensive, and cause damage to seeds during processing; its effectiveness usually lies only when drying seeds to extremely low moisture content (usually not routine greenhouse production).

How Does Humidity Impact Seed Germination?

How Does Humidity Impact Seed Germination?

How Does Moisture Impact Seed Viability?

Seed coats provide protection for embryonic leaves (cotyledons) and food sources (endosperm). Their purpose is to limit how much moisture the seed absorbs; however, this barrier cannot remain impenetrable forever: in extremely dry environments, it can break down, losing its potential germination rate, while extremely damp environments could see mold growth or even rot development resulting in their destruction.
Prior to planting seeds, they must first be freed of excess moisture; one effective way of doing this is through drying. Seeds should be carefully separated from their pod or fruit sources before being spread out onto fine screens or parchment paper in a warm, dark location for drying. They should be stirred occasionally so as not to stick together; when ready for planting they will crack and snap open, revealing their cotyledons.
Seeds require adequate temperature and humidity levels as well as airflow to dry properly, helping them last longer while avoiding mold or mildew growth. Storing them in a basement or other cool, dry location would be ideal; otherwise a small amount of silica gel or powdered milk added to their storage container will absorb excess moisture to protect the seeds from spoilage.
Seeds should be stored in plastic bags, paper envelopes or glass jars to protect from mold or mildew growth. Refrigerators also offer optimal conditions as their low temperatures and humidity levels help protect seeds from mold or mildew growth. It is wise to store seeds away from areas experiencing drastic temperature variations, like garages or sheds, as this could lead to condensation, which damages seeds. When placing the seeds into your fridge use a fan to circulate airflow over them as this will prevent freezer burn.

How Does Moisture Impact Seed Viability?

How Does Moisture Impact Seed Viability?

How Can Silica Gel Save Seeds from Drying Out?

Have you seen silica gel packets everywhere from shoes and clothing packages, pill packaging and beef jerky packs to your shoes and shipped clothing? These little beads (known as xerogels in technical terms) absorb moisture and act as moisture-absorbing desiccants that prevent mold growth, mildew growth and corrosion within containers and storage areas.
Silica gel can be purchased at most grocery stores or pharmacies as a packet, being an amorphous form of silicon dioxide with nanometer-scale pores and voids that bind water molecules at high levels while remaining virtually insoluble with other liquids; hence it is used to dry items that will be packaged or stored for long periods such as photos, artwork, books, instruments and food products.
Seed drying requires low humidity levels and even temperatures, and adding silica gel packs can help ensure they will be ready to plant come planting season.
If you have a large pile of seeds for next season, using silica gel can speed up their drying time and get them ready sooner. Simply combine equal weights of seed and silica gel in an airtight jar such as Seed Saver Vial or barrier pouch, seal, then cover it with either muslin or reemae for seven days until finished drying.
Silica gel will absorb any excess moisture left behind in a seed. Be wary not to allow too much silica gel into your system as this could starve its energy reserves needed for the growth and development of new plants. You can add additional silica gel if required.
Color-indicating silica gel makes it easier to determine when seeds have completely dried out. Once they’ve absorbed enough moisture, its color will shift from blue to pink indicating it is safe to remove the seed from its storage container.

How Can Silica Gel Save Seeds from Drying Out?

How Can Silica Gel Save Seeds from Drying Out?

Be sure to read our other related stories at SeedOilNews to learn more about seed oils.