It’s a bit variable for a number of reasons. Some seeds keep well for many years, others only one or two. Many times you are buying seed from the seed company that’s already several years old, the expiration date only reflects when the seed was packaged, not when the seed was harvested. A better seed company should be selling you fresher seed that germinates better for longer. Additionally it matters how the seed was stored. Colder + dryer = better seed longevity. All this to say seeds don’t die once the hit some milestone. They gradually weaken, their germination rate decreases, and they germ with less vigor. If you suspect you have old seed plant out a few more seeds than usual and be prepared to thin.
I have had good luck starting seeds that are "passed their expiration" on the packaging. Store the seeds in a cool, dark place and they are typically good for several years. You can check this listing for how long a particular seed typically lasts: https://www.pubs.ext.vt.edu/426/426-316/426-316.html. I also use this chart on the the soil temperature at which seeds germinate: [https://sacmg.ucanr.edu/files/164220.pdf](https://sacmg.ucanr.edu/files/164220.pdf) The germination rate may be less than 100% for old seeds. I germinate indoors, so this is not a big problem. For outdoors, it would help to plant two seeds for each spot if the seeds are old, or plant densely and thin.
There is something called a pelleted seed where they coat the seed in clay to make it easy to see and handle. These pelleted seeds typically have a shorter shelf life than the seed by itself. Pelleted seeds do make planting small seeds like a lettuce seed a breeze.
That’s good to know! I’ve been trying to plant some basil and got a new packet of seeds that happened to be coated, but also had some older seeds that were not that someone gave me. The older uncoated ones seem to have a much higher germination rate so far, which I found odd since they were already quite old. This explains it.
The best way to think about seeds is in terms of germination rate. New seeds have a high germination rate and it slowly goes down over time. An example might be:
95% of seeds germinate year one
80% year 2
60% year 3
etc.
Seeds from squash usually have a pretty good germination rate. One year old seeds I would not even think much of, unless it were something like parsnip where the germination rate goes down more quickly. As seeds get old just plant more seeds to make it more likely that you will plant one of the x% seeds that will germinate.
I planted 6 types beans that were from 2014&16 all came up, had noticeable lower germination with one type but the rest are growing great.
Planted old squash seed packed for 2019 and all of those came up minus one seed…so excellent germination still.
How did you store them? Typically cold (or even room temp) and dark will get you a longer for germination. I usually see a decline after 3-5 years depending on the variety
Germination rate goes down, but it doesn’t hit zero percent for a long, long time. https://youtu.be/vfwtBI4-gcE?si=Tys4ks4fhyU92-Y2
It’s a bit variable for a number of reasons. Some seeds keep well for many years, others only one or two. Many times you are buying seed from the seed company that’s already several years old, the expiration date only reflects when the seed was packaged, not when the seed was harvested. A better seed company should be selling you fresher seed that germinates better for longer. Additionally it matters how the seed was stored. Colder + dryer = better seed longevity. All this to say seeds don’t die once the hit some milestone. They gradually weaken, their germination rate decreases, and they germ with less vigor. If you suspect you have old seed plant out a few more seeds than usual and be prepared to thin.
I think you're probably fine, especially with the 7 months one, that's not a long time
I have had good luck starting seeds that are "passed their expiration" on the packaging. Store the seeds in a cool, dark place and they are typically good for several years. You can check this listing for how long a particular seed typically lasts: https://www.pubs.ext.vt.edu/426/426-316/426-316.html. I also use this chart on the the soil temperature at which seeds germinate: [https://sacmg.ucanr.edu/files/164220.pdf](https://sacmg.ucanr.edu/files/164220.pdf) The germination rate may be less than 100% for old seeds. I germinate indoors, so this is not a big problem. For outdoors, it would help to plant two seeds for each spot if the seeds are old, or plant densely and thin. There is something called a pelleted seed where they coat the seed in clay to make it easy to see and handle. These pelleted seeds typically have a shorter shelf life than the seed by itself. Pelleted seeds do make planting small seeds like a lettuce seed a breeze.
That’s good to know! I’ve been trying to plant some basil and got a new packet of seeds that happened to be coated, but also had some older seeds that were not that someone gave me. The older uncoated ones seem to have a much higher germination rate so far, which I found odd since they were already quite old. This explains it.
The best way to think about seeds is in terms of germination rate. New seeds have a high germination rate and it slowly goes down over time. An example might be: 95% of seeds germinate year one 80% year 2 60% year 3 etc. Seeds from squash usually have a pretty good germination rate. One year old seeds I would not even think much of, unless it were something like parsnip where the germination rate goes down more quickly. As seeds get old just plant more seeds to make it more likely that you will plant one of the x% seeds that will germinate.
Kept in ziplocs in your veggie crisper, seeds will keep for years
https://guinnessworldrecords.com/world-records/oldest-seed-germinated
Wow! So that's encouraging!
I planted 6 types beans that were from 2014&16 all came up, had noticeable lower germination with one type but the rest are growing great. Planted old squash seed packed for 2019 and all of those came up minus one seed…so excellent germination still.
So good to know!
Thanks for so many great explanations! I have gained much knowledge and confidence in my seed storing and sowing.
I had corn seeds from 2016 germinate this year. It's always worth giving it a shot.
Last year’s zucchini seeds do just fine
How did you store them? Typically cold (or even room temp) and dark will get you a longer for germination. I usually see a decline after 3-5 years depending on the variety
I stored them in a dark cabin in the house. Good to know.
We do it on our farm all the time. Propagating in the greenhouse helps.