Have you ever wondered if it's a good idea to stock up on seeds, or how long seeds will last in storage? In this post, I cover how long different varieties of seeds can be stored, the right way to store seeds, expected germination rates after storage, and a simple germination test.
I also share my personal favorite seed sources and why I like their seeds.
These are my favorite seed sources, which have provided me with seeds that have grown well here in northeast Wisconsin.
Fedco Seeds – Fedco is where I buy the bulk of my seeds. Their prices are very affordable, they carry a large number of varieties, and they source from ecologically sound growers – no GMOs here.
Their catalog is not flashy – it's printed on plain newsprint, all black and white – but their variety descriptions are tops. They point out which varieties store best, are best in certain recipes, and are resistant to various garden problems. They also give troubleshooting tips.
Baker Creek Heirloom Seeds – I'm new to Baker Creek, but I'm a fan. One of the best for unusual heirloom and open-pollinated varieties, plus reasonable prices. Gorgeous photos in the print catalog and online.
They've launched a customer review option online, but so far the feedback is minimal. I expect it to grow over time. Forward thinking company, also GMO-free and supporting local farmers, like Fedco.
Pinetree Garden Seeds – Out of my top five, I've been ordering from Pinetree the longest. Their prices are reasonable, and they give smaller quantities of seed in each packet so you don't end up carrying over so much seed from one year to the next if you have a smaller garden.
I typically order from Pinetree for seeds that have a limited storage lifespan, like peppers and parsnips. Again, another company that is GMO-free and supports healthy farms and farmers.
Seed Savers Exchange – I love the idea of Seed Savers Exchange, and they have a beautiful and inspiring catalog – BUT – not all the seeds I've ordered from them have had the quality I expect from a seed company.
Germination rates have been poor, squash that were supposed to store well stored poorly (they were the first to rot in storage our of six varieties), plants have failed to thrive (right next to similar plants from other seeds sources), and tomatoes that were described as crack resistant cracked worse than any others in my garden (and I grow around 20 varieties).
When I emailed with my concerns, I received no response. I am still a member of SSE, support their work and order from them occasionally, but don't rely on them for the bulk of my seeds.
How Long Can You Store Seeds?
So, once you've got your seeds, how long can you expect them to remain viable? The following charts from Seedman.com lists storage and germination times for garden seeds. My results have been somewhat different, generally with a longer shelf life than this list suggests.
I've started keeping records for the seedlings I start inside, listing planting date, variety, number of cells, number of seeds, year of seeds, seed company, date of first seedlings, number of seedlings, final number of seedlings and date of final count.
I pop these titles into Excel, make a grid and print it horizontally on a page. This allows me to keep track of whether or not I need fresh seeds for a variety even if I have a lot of seeds left.
For instance, I've got some tomato seeds left from 2001 (ten years old) that came up great this year, and others that only sprouted one out of ten seeds.
|Crop||Seeds per Ouncea||Relative Longevity under Cool, Dry Condition (Years)bc|
|Bean, Lima||25 – 75||3|
|New Zealand Spinach||350||5|
|Onion||9,000||1 – 2|
|Parsnip||12,000||1 – 2|
|Pea||75 – 90||3|
|Sweetcorn||120 – 180||1 – 2|
|Swiss Chard||1,500||1 – 2|
|Watermelon||200 – 300||5|
aSeeds, The Yearbook of Agriculture. 1961. Stefferud, A., Editor. The United States Government Printing Office.
bHandbook for Vegetable Growers. 1960. Knott, Joe. John Wiley and Sons, Inc.
cVegetable Growing Handbook. 1979. Splittstoesser, W.E. AVI Publishing, Inc.
|Crop||Minimum Percent Germinationab||Germination Temperatureb||Days to Germinate Under Optimum Temperature and Moisture Conditionsc|
|Min °F||Opt. °F||Max. °F|
|New Zealand Spinach||40||70||6|
aMinimum percent germination to federal standards.
bHandbook for Vegetable Growers. 1960. Knott, J.E. John Wiley and Sons, Inc.
cSeeds, The Yearbook of Agriculture. 1961. Stefferud, A., Editor. The United States Government Printing Office.
What's the Right Way to Store Seeds?
According to the article from Seedman.com “The dry seed should be placed in packages and stored in moisture-proof containers. Containers such as sealed cans or jars with air tight caps work satisfactorily. Storage temperatures between 35°F and 50°F are satisfactory when the moisture content of the seed is low.”
I keep my seeds in my cool, dry basement to help extend their lives, but they could be a little cooler. My friend keeps hers in their walk in cooler and has significantly better longevity. I may have to bum some cooler space once most of planting is over.
Don't leave your seeds sitting in a greenhouse or near a heat source, like near a furnace or in your kitchen! This will shorten their lives.
Simple Germination Test
If you want to check if your seeds are likely to grow, try this simple germination test.
- Wet down a paper towel.
- Place ten seeds on the towel, fold to cover the seeds (so they are in contact with the damp towel on both sides and not too close to the edge of the towel).
- Place towel in a plastic bag with the top open, or in a mason jar. You want some air flow, but you don't want the towel to dry out near the seeds.
- Put in a warm area. Check seeds daily. Most seeds should sprout in 3-10 days. (Varieties that take longer to sprout may be noted on the seed package.)
- If they all sprout or most of them sprout, you're good to go. If half or less sprout, you'll need to “Plant them thicker than hair on a dog's back” (as my mom would have said) or buy new seeds.
You can also use your setup for sprouts to check germination rates or presprout a bunch of seeds before planting. This works well for me for early spring peas, which sometimes have trouble getting started in the cool ground but do well once growing.
What are your favorite seed sources and how do you store your seeds? I'm always open to trying something new.
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