Just a warning: I’m going to present a contrarian viewpoint on planting old seed here based on my own experience that I’ll detail below. I’m quite willing to accept that my results are a fluke. But, my results are at least interesting. Do old seeds grow? I’d say yes! (or at least – maybe)
Most (all?) websites I have looked at, whether it be bulletin boards, articles or whatever, strongly indicate that you are wasting your time trying to grow seed that is a couple of years or more beyond its sell-by date. I’ve seen more than one of post suggesting you just put anything over two years past its “sow by” date in the bin.
This may be true for unpackaged seed (by that I mean seeds not in a sealed foil wrapper) but I don’t think it is necessarily true otherwise.
Obviously seed will deteriorate over time. That is a given. But the questions are: “how much deterioration (i.e. germination rate) and how long.
Old Seed: The Experiment
Last year I decided I wanted to start growing herbs. I’ve been growing Chives for quite some time but nothing else. I remembered getting a multipack of herbs seed a while back. In fact it was from these I started growing the Chives. The other three herbs (Sweet Basil, Coariander and Parsley) were still in their little foil wrappers.
I looked on the packet. It said “packed 2008” sow by 2011. I have a penchant for agricultural experimentation (see this post on growing an apple tree from seed!) So I propagated them anyway. When I did this it was 2021. They were ten years out of date! I considered not bothering but on a whim decided to try an experiment and grow a few of each type on kitchen roll. As a control I grew some cress and mustard in the same way.
I placed the seed on kitchen roll then inserted that into a zip lock transparent food bag. Then I added a little water enough to make the kitchen roll in the zip lock bag soggy. Finally I blew into the zip lock bag to inflate it, zipped it up and retired to a safe distance.
As expected the Cress and Mustard loved it in their damp little greenhouse and prospered.
But so did the seed that was ten years past its “use by date”
“Mostly” the seeds grew.
So it looks like may still get a useful batch of seedlings from old seed as long as that seed is in a foil wrapping.
Maybe I was lucky. Or possibly these species are more capable than others of surviving for 13 years from packing.
But, I would suggest that if you have some old (and dare I say) expensive seed, rather than chucking it in the bin, find a seed tray and bit of compost and chuck them in there. Or of course you can get by like me with a zip lock bag and a bit of kitchen roll.
Now what about seed that is not in a foil wrapper? Sadly I haven’t performed an experiment on the many old un-foil wrapped seeds I have so this is a bit anecdotal.
But I did buy a pile of seeds in a closing down sale some years ago. These are not foil wrapped. The ones left still mostly work (Tomatoes and Beetroot). The yield may be lower but frankly I still have more plants than I know what to do with. These seeds have a “plant by” date of 2016.
I also have hoards of seed I take from my own plants. I have chilli pepper seed going back ten years which I have yet to experiment with. But I have successfully grown Chilli’s from seed thats two and three years old. True the yield is down, but when you have 500+ seed and want a maximum of ten plants it’s a no-brainer.
I’m planning to try an experiment on my older seed like the one for the foil wrapped herbs, just to see what happens.
The problem is getting round to it!