Seeds of Eryngium giganteum are best sown fresh and often need a cold stratification period of 1 to 2 months before they will germinate. Stratification = exposed to cold. Seeds must be in a slightly moist medium (= not wet!) otherwise stratification does not work.

If you have sown the seeds in a pot I suggest putting the pot in a plastic bag, close it and put it in the fridge at 1 to 6 degrees Celsius for 1 to 2 months. After this period place the pot at 15 to 20 degrees Celsius and seeds should start to germinate (that is if the seeds are still viable).

Tom Clothier's Germination Database suggests for Eryngium giganteum: "sow 4 wks @ 68ºF, 6 wks @ 39ºF, germ.
@ 53ºF , 10-20d". This would mean that the seeds need a warm stratification before the cold stratification period. I have however succeeded with this species without the warm stratification period.

Tom Cothier's Germination Database

It is always wise to check the best way to get seeds germinated before the actual sowing.

Gardenprince, thanks for your advise. I did almost the same process as you except I did not record the temperature.

According to the Select seeds information, if no germ in 30 days after chill, repeat warm/chill cycle or sow outdoors in nursery bed in late summer to fall. I wonder should I let seeds outside for winter or bring it back in basement.

How long did you seeds take to germinate? What's you success rate?

This is disconcerting - I sowed these (and planum and yuccifolium) back in Septermber too - and, after a warm autumn, all my eryngoes are up and off - in fact, had to prick out e,giganteum. Where did the seeds come from - the apiaceae family, as a rule, need to be freshly gathered? I could send you some of mine which definitely are from this season.

Hi Campanula,

Thanks so much!It's very kind of you offering the seeds.

I got my seeds from select seeds this year and still have twenty seeds left. I will try it again in December.

What's your sowing method? Can you share more? I want to learn more before my next try.

Afraid I am very slapdash - pretty much any handy loam based potting media - I have, in extremis, used old veggie containers (cukes or greenhouse tomatoes) as long as the mix doesn't clump, or waterlog - although I might add a bit of vermiculite or perlite or horticultural sand - I honestly use what's to hand. I avoid flats (or trays, as we call them) because they tend to dry out and also, the roots, having nowhere to go except horizontally, tend to splay out, entangling with each other - pricking out or separating seedlings is much easier to upturn the entire pot and the roots will separate very easily - I find using deeper litre pots - about 5 inches deep with 4inches of medium - maintains a fairly even moisture level. Finally, I rarely cover seeds - topping the pots with flint based chick-grit |(infinitely cheaper than horticultural grit). Tiny seeds, I sprinkle on top of the grit and let them percolate downwards - if you water from the bottom, it makes a good contact between seed and soil as osmosis (and gravity) tends to pull the seeds into the top layer of soil. The grit also helps to keep the surface moist and prevents moss growing (I tend to leave the pots uncovered over winter, outside to stratify naturally. I don't use lights, heat, hormones or keep stuff in the fridge unless I had some rare or special seed,

Campanula,

Thanks for all indeed! I feel so warm even though it's snowing. Will continue to grow another lot in your way. :) :) :)