Monday, March 06, 2017

testing old seed

I like to use old seed as long as I can. My last two plantings, I've seeded single pots of my old seed to see if it's still viable. I'm labeling and keeping track of it. I have Seed from 2009 to 2017. The 2009 seed is 8 years old! No doubt dead. I think this will give me a sense over time of how long I am able to save different types of seed. It's also a plain old test of the old seed. If it doesn't germinate, I toss it.

The seeds I sow early are particularly important to be viable. For seed like celeriac that takes a week or so to germinate, and also onions that germinate faster but still take time to grow, I don't want to find out in April that my seed was too old.

If I have lots of viable old seed then I'll get a bumper crop if seedlings and more to share. And I'll save the seed and give it a try again next year.

5 comments:

Anonymous said...

I have a chart that is pretty accurate about seed life...however for some reason this spring even some of my brand new seed is not germinating...nothing has changed in my process except the seed starting mix...I was not able to find my usual one... has anyone else had this problem?

Anonymous said...

Hi Kathy,

I have seeds that I bought just before Spring 2015. I was hoping to use a lot of those seeds for this year's garden. Do you think they will still be good?

kathy said...

I am wondering if your seed isn't germinating because maybe the seed mix is old or wasn't properly sterilized. If there is fungus in the soil, seeds will rot before they germinate. Do you notice damping off of any seedlings that did sprout? Fungus gnats? If so, you might try putting a thin layer of vermiculite on top and increase air circulation with a fan.

Are the new seeds that aren't germinating ones you've grown before? Some seeds require special conditions (like, peppers need >78F to germinate). Some just take a long time. Every once in a while I get a package that doesn't germinate, so if's just one package, I wouldn't worry about it and I'd buy another.

To figure out if it is the soil mix, maybe you can find a small bag of your usual one and do a comparison test, starting a few of the same seeds side by side in each soil.

The problems I've had like this were from unsterile soil, temperature colder than I realized, and using dirty pots from last year.

kathy said...

Seeds packaged for sale in 2015 are 2 years old now. The onions, carrots, parsnips and parsley will be hit-or-miss, depending on how they've been stored. In fact, how they've been stored is an issue for all of them. Humidity and temperature are important factors, generally the colder and dryer the better.

I've been trying to keep better track of how my seeds germinate for me given the way I store them (just at room temp and NE humidity). On my 2017 planting list (a couple posts below), I've marked the year the seeds were packaged for and if the seeds germinated or not.

For this one year, I find the following viability times:
onion - 3 years
leeks - 4 years
arugula - 5-6 years
cabbage - 7 years

I'm going to keep track of these over a few years and make a chart of my own.

To test viability before planting, you can put seeds in a damp paper towel for a few days to a week and if the seed sprouts.

kathy said...

Another thing about the seed starting soil is to make sure the bag is closed up when you finish using it. If it's left en it can get fungi in it. I bought a big compressed bag of Sunshine mix this year and poured some out into a bucket. I just realized that I can't leave it sitting out for weeks in an open bucket so I poured it into a plastic bag.

I hope some of these thoughts are helpful.