Do you have more seeds at hand than you can grow at one time? It happens to all of us. We can get too avid and buy too many seeds. Don’t worry, they don’t have to end up as waste. If you have more seeds than you have room to grow, storing them properly can make them last longer and your investment will give you your best harvest.
So, how long do microgreen seeds last? If your seeds are stored correctly, they remain viable from one up to three years, or even longer, depending on the type. They need to be stored in a dark and dry condition for them to last long. Factors such as humidity and degrees above 50 degrees (10°c), shorten a seed’s shelf life, so the refrigerator is generally the best place to store them.
Even if you are being careful about storing your seeds, you may end up with some not being able to germinate. Keep reading to find out if you can still grow “out-of-date” seeds, why it is important with proper storage, and how you can maximize shelf time of seeds to make them last longer.
How long are Microgreen seeds viable?
How long microgreen seeds maintain to be viable depends on a few factors and they are all important.
Type – There are numerous variations of microgreens. Depending on the type of seed, that may affect how long they stay viable. You can always check the date on the package as with any other fresh products.
Age – How long you store the seeds will impact the germination rate. All seeds stay viable for at least a year and most will be viable for two to three years.
Storage conditions – How you store your seeds will impact their viability. Even if the type of seed has a long time before they are considered to go “out of date”, if you store them improperly, they may not germinate.
How to store seeds to make them last longer
You can keep your seeds stay viable for longer if you store them under the right conditions. Microgreen seeds must be stored properly to conserve their vigor and vitality. Seeds are sensitive to humidity and must always be kept dry. If they are not conserved well they may be ruined and will not germinate.
Several factors will impact the length of time seeds can be stored. Even the environmental conditions in which the seed was produced and collected has an impact. With a little preparation, some seeds can last several years.
What are the optimal storing conditions?
The most important step is keeping the seeds at a constant temperature and humidity. The ideal storage condition is a temperature below 50 degrees Fahrenheit and less than 50 percent humidity.
Excessive storage temperature and humidity are known to kill seeds. Storing seeds that have not been properly dried may result in mold which destroys the seed. So remember, the key factor for keeping your seeds viable for longer is to keep them dry and cool.
According to US Davis Seed Biotechnology Center, the viability period for seeds decreases by half for every 1% increase in seed moisture content or 10°F (~5°C) increase in temperature. A common rule of thumb is that the temperature (in Fahrenheit) plus the relative humidity in the air (in percent) should total less than 100 for satisfactory seed storage.
Where to store seeds to make them last longer?
The best way to store seeds is to keep them cool, dry, and in a dark place. As the temperature is an important factor, you should consider where you store them depending on your climate conditions.
You can place your seeds in a cupboard, in a fridge, or any other storage place where it is constantly dry and cool.
If you are living in a humid and warmer climate or just have a high indoor temperature, the best place to store your seeds in the fridge. As seeds are sensitive to heat, the fridge ensures they are kept in the right temperature which is below 50 degrees.
When you are ready to plant your seeds, you should take them out from the refrigerator and give them time to get to room temperature. If they are still damp or wet, they can clump together when sprinkling the seeds on your growing medium.
Ensure not to take out the seeds so they get humid and put them back in its container. If they do get damp or wet, you should always make sure to dry them before storing them again.
If you have many different seeds, don’t mix them up in the same container and label them. When you store for a longer time you may forget what you have stored and you’d want to remember what nutritious superfood they will provide you.
What containers can be used for storing?
There are different ways you can store your seeds to make them last longer. For large commercial production, seed banks store seeds in moisture-proof containers. When you are growing for a home purpose only, there are more simple options to ensure your seeds will last you longer. You can find below some different choices.
Paper bag or Envelope
A paper bag or envelope works well for the seeds that will be stored for a short time. You can place the bag in a refrigerator or any other cool and dry area. If you place the paper in the fridge, you must ensure that you have no other products which are standing so close that they transfer humidity or any liquid. If you have a small amount of desiccant such as silica gel, you can place that in the bag. That is a great alternative to absorb any damp.
Food jars and glass containers
If you have food jars lying around or other glass containers, you can use these as well for storing your seeds. The good things with food jars and other sealed glass containers are they prevent circulating air from entering the container. You can also add a small amount of desiccant to these to prevent moisture. The risk with using sealed containers is that if the seeds and the container are not completely dry before closure, any moisture trapped inside the container ruins the seed.
Zip-lock storage bags
Zip-lock bags are another good alternative to store your seeds. You must ensure the bags are completely intact and not sipping air so that humidity can enter the bag. It has been said before, but the importance of it is high, so it is worth mentioning again; the seeds and the container, in this case, the plastic bag, must be completely dry or the seeds may be destroyed and cannot be germinated.
Can I store seeds in the freezer?
You can store seeds in the freezer but we wouldn’t recommend it. When the seeds are frozen and you take them out, water is formed by the thawing and when we are talking about seeds that have not yet sprouted, they should not be wet. Only when it is time for growing, some types of seeds should soak in water pre-planting.
If you are keeping seeds in the freezer, ensure to quickly take out those you need and dry them. Keep the rest dried in the container and not let them thaw. Then put the container back in the freezer.
Can you still use “out of date” seeds?
If you have ended up storing your seeds for a long time and not realized the time they have been laying around, you may wonder if they are still good to plant. Is it a waste of time germinating old seeds?
No, it may not be a waste. It is surely possible to plant seeds that have been stored for a long time. If you think about it, there is no harm in planting old seeds. If they germinate, the same quality plant will come from the seeds as those that were within the right date. The problem is actually not about the quality of the plants or if they are harmless, it’s rather the chances of getting old seeds to germinate. You can always try and if nothing is coming out of the seeds, then what you have lost is time.
What is the difference between dry seed and soaked seed?
You may have heard about dry seeds and soaked seeds. When we talk about seeds requiring soaking before they are planed, this relates to the growing process and not storage. Before you plant seeds, some types require soaking for a certain amount of time before they can grow. This quickens the germination process.
In all cases, when we are talking about storing and making seeds last for longer, they must be dry.
Buy in volume or smaller batches
Now when you have read that seeds can be viable for a long time applying the right storage, you may wonder if you are better off buying in bulk and store or to buy in small batches. Microgreen seeds can be expensive depending on the type. Seeds can be bought in sizes of small packages that give you a handful of microgreens up to sacks with several pounds of weight. You may consider buying a larger volume to stack up and save some money. The decision to buy volume or in smaller batches depends on your circumstances. If you are growing larger volumes you would probably invest in larger volumes of seeds, but if you are growing from time to time, you may go for the smaller batches and even microgreens kits which include seeds.
We prefer to buy in volumes which will last us for a couple of months and then we buy another round. We live in the Meditteranean and with indoor temperatures hitting more than 70 degrees in the summer, we store them in the fridge. With such a humid climate and not having too much indoor space, this makes us better prepared for an all-year growing plan.
How long will microgreens last after harvesting?
Even after your microgreens are harvested you can store them. If you grow more than you can eat, you can preserve them to make them last longer. Most microgreens will last a week or two when they are stored properly in the refrigerator. That means that after the harvest they must be dried and put in a sealed container or plastic bag. They will not last you long if you keep them at room temperature. The same goes for seeds and other types of vegetables.
After you have harvested your microgreens, you must dry them well after rinsing (which you may want to do to get rid of any soil residue if planted with soil). Same as with seeds, you need your readily grown microgreens to be completely dry before you seal them. That will extend their shelf life. A simple tip is to add some paper towels at the bottom of an airtight container to help absorb any moisture. This way you ensure that should there be any remains of damp it will absorb. If they are exposed to too much humidity they will turn into a soggy mash before their quality should degrade.
You can store your seeds for a long time before you use them. If you have ended up with too many seeds and you cannot plant them all at once, there is no need to worry, they have not gone to waste.
Microgreens are an excellent way to keep you equipped with superfoods for a long time. The duration you can keep seeds stored varies depending on the type, but in general, they will last you at least 2 years. The most important thing is to keep them dry and in a dark and cool place.
Getting the best shelf life out of your microgreen seeds ultimately depends on how you treat them. Following the tips we have shared, it should give you comfort that you can invest in seeds, keep them stored, and as such have these amazing superfoods available all year round.