My favourite is A.agavifolium. Not really the colour that you are after but great foliage and very hardy............

HamiltonSquare said:'Neptunes Gold' never bloomed and I think it bit the dust for good this year

That isn't good to hear as I planted two NG last summer.

(I really like our "Big Blue". The steel blue colour is spectacular and it is much more self supporting than other sea holly varieties I have tried).

I am growing my first Eryngium Blue Sea Holly this year. I got 2 roots and potted them and have them growing in my garage under lights. Both of them are growing. I plan on transplanting them in the ground as soon as the ground is warm enough. I am so excited and can't wait to see blooms.





I hope I can keep these 2 alive until I can get them planted outside.

@foraygardengirl Jeanie, I see that you have the Blue Sea Holly. Could you tell me if the pictures that I just posted of mine are looking okay? I have them under lights in my garage. I plan to transplant them outside as soon as the weather is going to stay warm enough.

Jeanne, looks good to me. I have actually tried to remove these from the spot where I had them planted, as I wanted to change to a strictly daylily bed, and the sea holly keeps on coming back!

So you are saying that it can take over or is invasive? Maybe I should bury a big pot into the ground where I am going to put it. Does it spread by roots or does it reseed? Maybe I will have to put it some place were I don't care if it spreads. I'd love to hear your thoughts, Jeanie or anyone else who has this plant, "eryngium Blue Sea Holly"..

I'd love to have a blue one that re-seeds reliably. I don't think the roots are invasive though.

I don't think I would call them invasive. I cannot determine if they self seeded or if I missed some of the roots when I moved them. I may never know

From pictures 'Jade Frost' looks to be my favorite and I'm still looking for a plant for sale.

I had either Big Blue, or Sapphire & found out, after thinking it was sterile hybrid, it in fact produced seeds. The planum species can be or get rather leggy & flop, from too much water, or rain. The 'Hobbit' was released, as a much shorter version.
I actually prefer E.alpinum, but it is more difficult not only to start from seeds, but to get true to name species or cultivars. Seed can be very difficult to germinate unless fresh, or treated as "difficult" alpine, with stratification
The seeds of the 'Ghost' sort , if not fresh, tend not to germinate either., & is usually biennial & may die after blooming & therefore fresh seed is best. Being biennial, needs to be sown, for two consecutive years, or you only tend to get flowers every other year. Some just order plants, two years in a row, as seed is difficult.
Actual "sea holly" can grow along coastlines of Mediterranean beach areas, near dune lines & is maritimum.

My favorite is Eryngium alpinum.. You can easily tell it apart from planum, when you purchase by mail order & it breaks dormancy. The Alpine has heart shaped leaves, (somewhat triangular) with very serrated edges & pointed leaf tip.
Whereas, the more common - planum- has oval shaped leaves, with less serrated leaf margins & lacks the distinct point at the leaf tip.
It is often "substituted" as the seeds are easily grown, more like a weed than the more difficult to germinate alpinum species. The seeds of planum, are much less expensive, too, while alpinum seed usually requires stratification, unless you are able to germinate warm, as if it just fallen after becoming ripe on bract in warmer weater, before it would naturally get cool, up in the Alps of Europe, in nature.. I will try to get a photo for you

Lets see if I can get my act together & do a couple of photos. First one, ought to be species Eryngium alpinum & they can vary in color, from geyish blue, to darker blue & have differences in number & size of the bracts. The next one, was "sold as" 'Sapphire Blue', but may have faded from bright, June nearly full exposure sunshine, rather quickly...