Seed viability, part 2: Potting up the sprouts

I began the germination test on my hollyhock seeds on January 7. Yesterday, I opened up the bag to find ‘The Watchman’ ready for duty.

germinated hollyhock seed

From your test, gently unfold the paper towel and see what’s happening. The photo above shows an excellent germination rate, and indicates the seed is still quite viable. In fact, of the 17 seeds I tested, 15 sprouted (88% germination rate, or 15/17). I’ve opened up towels to find the seeds exactly as I left them, which is depressing until you remember that that means you must purchase fresh seed.

What to do with them now? Keep them going. And here is a tip: They don’t care to grow on in paper towels. Pot them up!

Potting up bag-germinated seedlings

The seedlings at this stage have only their cotyledons, or seed leaves. Any handling of these seedlings must be done by grasping (gently!) the leaves, not the stem (more properly, the hypocotyl). And to slightly complicate matters, some of the roots have grown through the layer of paper towel.

seedlings embedded in towel

1.  Prepare a seed flat as you would if you were sowing fresh seed (which, clearly, you are).  Use a clean container and fill it with sterile seed-starting mix. Moisten the mix and tamp it down well.

seed pan ready

A clean seed pan filled with moistened, sterile seed-starting mix.

2. Grasp the seed leaves and pull slowly, firmly, but gently. Some of the seedlings may be just beginning to penetrate the paper towel, in which case you may be able to free them entirely. They’ll look a bit like bean sprouts you might find on a salad bar.

bare hollyhock seedlings

3. Make a slit or trench in the seed flat using a spoon or knife. Your finger will work just as well. Lay the seedling into the trench up to where the leaves fork from the stem.

seedling entrenched

4. Gently firm the soil back over the stem and root. Follow the same procedure for additional seedlings, but don’t overcrowd the flat. I’ve allowed six seedlings to a flat 3 inches wide by 6 inches long. None of the roots overlap.

seedlings potted up into the seed flat

5. Keep the flat warm (65-70 degrees) and well lit, either in a sunny windowsill or under a grow light. A fine dusting of sand, vermiculite, or even chicken grit can help to fend off damping-off.

In one more post, I’ll show you how to pot up those seedlings that refuse to release their security paper towel.


9 thoughts on “Seed viability, part 2: Potting up the sprouts

  1. You seem like my kind of plant in the enthusiast. I had a greenhouse business for seven years and I love growing from seed or cuttings. I have a new plant called a blackberry willow that I intend to grow from seed this year.

      • Is that Belamcanda chinensis? (though I think it has a more up to date name, now.) I am growing some of those from seed this year as well. I had one plant that did sweet nothing for about five years, and last spring I obtained some additional ones from a friend. Well, all last year my old-timer struggled to keep up with its younger, fitter competition, and I must say it made a respectable showing. Between it and the newcomers, I have perhaps a pint of seed. They’re lovely, glossy black pearls, and the flowers are quite tropical looking and orchid-like.

        I do enjoy growing things from seed and cuttings, although it’s only in the past year or two that I’ve begun to feel truly competent at it. I’ve discovered that perhaps the best thing I can do is to leave the poor things alone. What’s your favorite plant to grow from seed?

      • Well, I don;t grow a tremendous amoutn of things from seed because I lack the discipline and knowledge of how to proper;y select and keep the seeds over. It will sound simplistic, but i enjoy sunflowers and collect those seeds each year and try to grow more from them.

        My uncle brought me a root from one of his blackberry lilies that I planted and I had several seeds from a stem I collected to try to grow this year.

        When I had the greenhouse I grew thousands of tomatoes from seed to sell. I still have several large bags of seed remaining that I grow each year. I keep them in the freezer and I suppose the germination rate slips a bit each year, but the price is right.

  2. Pingback: Seed viability, part 3: Planting seedlings embedded in paper toweling | MissingHenryMitchell

  3. Hi Joe, are you still keeping this blog? Do you still check replies? I am writing today – April 18, 2020 – to say that a week ago I used the (also my favorite) paper towel germination technique to check the viability of three colors of hollyhock seeds labeled 2001 that I had lost track of in some old boxes of stuff. I looked this morning but didn’t see any sprouts just yet and was thinking, Yeah, right – 19 years old, what did I really expect – but decided to cut one seed open to see what it looked like inside. It had been just about to sprout!! I know I’ll have at least a few viable seeds from that almost 2 decades old batch of salmon colored hollyhocks! If I hear from you regarding this post, I’ll let you know. Definitely the most exciting thing that’s happened to me yet this year!

    • Hi, Marghie.
      While I haven’t updated the blog in a really long time, I do still check replies. So glad the technique proved helpful to you–it sounds like it’s not the first time. Isn’t it remarkable how long some seeds can last, even under quite hostile conditions? If you get the hollyhocks to grow, please send a photo. I have an envelope full of mixed hollyhock seeds myself and may give them one last chance at glory, thanks to your note. I’ve got some acorn squash seeds under evaluation as I write.

      Stay well and happy gardening!
      PS–My name’s not Joe. 😉 Perhaps you are thinking of someone else?

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