They need a period of stratification in order to germinate – therefore sow in late summer or early autumn to germinate in spring. Grow in bright light, poor soil and good drainage :-)

I agree with Andrew Pegman. In case that the seeds of Eryngium genus do not germinate in "normal" condition, I suggest trying scarification in the first path. Scarification - a breach of the seed coat. You may put seeds into lukewarm water and than distort (or peel) the seed coat. As the second path, you may try the stratification.

Dalia,

Please follow the below given link and PDF attachment.

https://www.researchgate.net/publication/269656227_Effect_of_Seed_Treatment_and_Soaking_Duration_on_Germination_of_Eryngium_foetidum_L_Seeds

Good luck

Article Effect of Seed Treatment and Soaking Duration on Germination...

Dear Dalia Youssef

I suggest the following steps for germination of  eryngium seeds:

1- Check the viability of seeds by tetrazolium staining.

2- Treat seeds with 10 mM  GA3 for rapid dormancy breaking, or pre-chill the moist seeds at 5 ⁰C for 3-4 months.

3- Germinate the seeds at 25 ⁰C.

Best wishes

Kazem Ghassemi-Golezani

thankssssssssss a million to all  

Arvind Singh, thanks for paper i read it and i will try to mix factors

thanks for helping , best wishes for all 

Dalia, please see

Seed dormancy and germination of an

endangered coastal plant Eryngium maritimum

(Apiaceae)

Estonian Journal of Ecology · January 2013

DOI: 10.3176/eco.2013.2

thanks Maria Terezinha Silveira Paulilo 

i still try