Can I use these seeds?
March 10, 2014 6:38 AM   Subscribe

Despite the several inches of snow still on the ground, it's time to start thinking about gardening. I have some seeds left over from last year - are they going to be any good? How do I make sure that they're still viable?

We started a bunch of vegetables from seed last year, and we had pretty good success with most of them. However, I bought too many and we had a lot of seeds left over. After I planted last spring, I put all the seed packets in a large zip-top bag, sealed it, and stashed it in the (unheated, humid) basement. The seeds also came with a leaflet explaining how to store the extras which I skimmed and promptly threw in the trash. It said something about the refrigerator, I believe.

So, I have all these seeds which may or may not be any good this year. How do I determine if I should keep them? Should I just buy new seeds? Maybe try germinating one or two right now? If they are still good, do I need to do anything special with them when I plant or can they just go right in the ground like last year?
posted by backseatpilot to Home & Garden (10 answers total)
I planted some seeds from last year that I had stored in the freezer and they pretty much all came up here in my much warmer climate. If you want to get a head start go ahead and plant them indoors in small pots or flats. They'll probably be fine.
posted by mareli at 6:43 AM on March 10, 2014

Most seeds, if you keep them fairly cool and fairly dry, will be perfectly viable several years down the line. The fraction that germinate successfully will decrease year on year, at a rate that varies from one type of seed to another.

Best thing you can do is plant them all and see how it goes. My guess is that you'll have no problems. The biggest issue is likely to be the humidity you mentioned - seeds can be quite prone to fungal diseases, although many are treated to prevent this.
posted by pipeski at 6:48 AM on March 10, 2014 [3 favorites]

Most are probably fine. You can try germinating a sampling in damp paper towels, in plastic bags, or you can just plant the seeds more densely and plan on thinning out any extra plants.
posted by jon1270 at 6:49 AM on March 10, 2014 [3 favorites]

You can start them indoors in little trays (ice cube trays.) You can do a little greenhouse in your kitchen, when and if they sprout, you can plant them in your garden.
posted by Ruthless Bunny at 7:12 AM on March 10, 2014

I have successfully started seeds that were 5 years old. It helps if you keep them in a cool, dark place without too much humidity. Hopefully the bag you put them in kept most of the basement humidity out.

Basically with every year that passes, a few more of the seeds won't sprout, but assuming you've stored them well enough, there should be a number of viable seeds still in your packets.
posted by BlueJae at 7:29 AM on March 10, 2014

I think you'll be fine. I'd probably plant them a bit more densely than you did last year, and count on thinning your rows.

If you're not interested in taking the risk that they've gone bad (and losing the weeks it would take for you to figure that out) I see you having these options:

Replicate the archetypical 4th grade science fair project and germinate a statistically relevant sampling in a wet paper towel in plastic baggie. From that determine your germination rate, and plant accordingly.

Option 2: Get some seed starting cubes, and start a full planting of seeds indoors, or in a mini-greenhouse outdoors. You don't need all of the specialty equipment, a clear shower curtain liner as greenhouse cover, some dollar store ice cube trays/ old plastic bins. Bits of scrap wood and a staple gun. And if indoors, crafting/full spectrum UV lamp is better, but a reading lamp or two will do in a pinch.

Keep in mind, if your seeds turn out to be bust, you want your cost outlay for the starting equipment to be under the cost of prophylactically buying all new seeds.

I always had to start seeds in winter to get some spring crops in ahead of the Texas heat, and I didn't have the space required for bigger traditional seedling pots, so seed cubes were great. You can plant them directly as is. You'll want to transplant them up a size, if you don't have your ground temp where it needs to be by the time they get their first mature set of leaves, so factor that in your timing. (Ground temps weren't an issue in Texas, hours of sunlight was.) Plus its fun to watch if you do them inside!
posted by fontophilic at 7:30 AM on March 10, 2014

I've been successfully small-plot-gardening using leftovers for several years.
A new seed packet will have a high (>90%) germination rate
The next year will be pretty decent, ~50-75% or so. Unless it's carrots or parsnips, in which case it's going to be about 10%. Buy new seeds for those.
The third year, you're getting pretty slim, but definitely good enough germination rate that you can make it work.
I've got a small backyard garden, and if I want variety, I can only have a couple plants of each thing. So, for example, I want to have 2 cucumber plants. I buy a packet of seeds (75 or so). The first year, I start 3 seedlings, they all grow, and I set out the two healthiest. The second year, same thing but I might start 4 seedlings to be sure of two plants. The third year, I'd put 2-3 seeds in each of my 4 little seedling-starter dirt pods, and if more than one sprouts, pull out the smallest. Definitely won't have 100% germination, but I'm confident about getting my 2 plants.

If you're talking about planting a big garden, where you're not paying close attention to each seedling, this method is may start being too finicky.

Some vegetables stay good for a while; others really don't germinate well at all the second year. Carrots and parsnips are the ones I can think of, and I think lettuce is about a 2-year max. Fruiting plants (beans, peas, cucumber, tomato, pepper) are generally more robust seeds. If you're interested in a particular vegetable it should be pretty easy to look up.
posted by aimedwander at 7:50 AM on March 10, 2014

As others have said, you are probably fine with most of them. I put out bush beans and peas that were four years old last year and managed to get a good crop but had to replant twice to fill the gaps that didn't come up the first time. This just meant things matured at slightly different times, which can actually be a plus. Beets, arugula and cucumber have been planted for three years with no problems. In my experience leaf lettuce doesn't work well after the first year and spinach isn't great either. I also store my seeds in the basement.
posted by Cuke at 8:35 AM on March 10, 2014

The seeds don't go bad in a toxic way - they go bad in a dead way. You may have a lower germination rate, but for stuff you'd start in a small pot/egg carton/whathaveyou anyway, like tomatoes.
posted by maryr at 6:03 PM on March 10, 2014

Here's an article with a viability chart and some advice.
posted by lettuce dance at 7:33 PM on March 10, 2014

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