Illustration
Blue Glitter Sea Holly
Eryngium planum 'Blue Glitter'
Also called flat sea holly, blue eryngo, plains eryngo and blue glitter eryngium
Blue Glitter Sea Holly blooms from June through August.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Blue Glitter Sea Holly
Plant it in full sun. It prefers low water. It is hardy in USDA zones 5–8. Expect it to reach about 2.5 ft tall and 1.5 ft wide at maturity, in roughly 2 years (a house reading).
Pets
- Not yet checked for pets.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
No toxicity note is on file for Blue Glitter Sea Holly. That is not a clearance: check its safety for people and pets before planting.
What was checked
Mature height and spread, hardiness zones, sun, water, bloom months and color and the trait tags were checked against named botanical sources for this plant, with what the sources could not settle written down; years to mature size rests on a recorded house rule where no publisher states one, and is marked so; its common name and alternate names have not been checked yet. Each fact above carries its own mark. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Blue Glitter Sea Holly
Plant Blue Glitter Sea Holly in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 6, the middle of its hardy zones 5 to 8, spring means March to May and fall means August or September. Once settled, it blooms from June to August.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 6, the middle of this plant's hardy range, start with zone 6 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Blue Glitter Sea Holly get?
2.5 fttall5 ft 7 inan adult1.5 ftwideSee Blue Glitter Sea Holly in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Blue Glitter Sea Holly
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Blue Glitter Sea Holly about 1.5 ft apart, center to center, so each plant has room to reach its full width.
Add Blue Glitter Sea Holly to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Blue Glitter Sea Holly's height, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases, pests and toxicity were checked against 55 published sources on October 10, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Missouri Botanical Gardenits page for this cultivarheight, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
- Nature Hills Nurserymail-order nurseryheight, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
- Plant Addictsthe queue's store pageheight, spread, hardiness zones, sun, water, bloom months and color, trait tags, soil, diseases and pests
- Johnny's Selected Seedsseed househeight, spread, hardiness zones, sun, water, bloom months and color, trait tags and soil
- NC State Extensionspecies page, Eryngium planumhardiness zones, sun, water, bloom months and color, soil, diseases, pests and toxicity
- RHScultivar pageheight, spread, sun, water, bloom months and color, soil, diseases and pests
- selectseeds.comSelect Seeds (seed house)height, spread, hardiness zones, water, bloom months and color, trait tags, soil and pests
- Walters Gardenswholesale grower, Zeeland, Michigan; its page for this cultivarheight, spread, hardiness zones, sun, water, bloom months and color, soil and pests
- Perennials.com (Heritage Perennials)Valleybrook International Ventures, the Heritage Perennials program; p...height, spread, hardiness zones, sun, water, bloom months and color and soil
- pridescorner.comPrides Corner Farms (wholesale grower, Lebanon, Connecticut)height, spread, hardiness zones, sun, water and bloom months and color
- The Morton ArboretumLisle, Illinois; its species page, Eryngium planumsun, water, bloom months and color, soil, diseases and pests
- whiteflowerfarm.comWhite Flower Farm (mail-order nursery, Litchfield, Connecticut)height, spread, hardiness zones, bloom months and color, trait tags and soil
- almanacplanting.comAlmanac Planting Co. (mail-order store, Knox, Pennsylvania)height, spread, hardiness zones, bloom months and color and trait tags
- benary.comBenary (Ernst Benary Samenzucht, the breeder; its Glitter series page)height, hardiness zones, sun, water and bloom months and color
- High Country Gardensmail-order nursery for waterwise plantsheight, spread, hardiness zones, water and bloom months and color
- hortech.comHortech (wholesale grower of perennials and ground covers, Nunica, Mic...height, hardiness zones, water, bloom months and color and trait tags
- anniesannuals.comAnnie's Annuals and Perennials (mail-order nursery)height, hardiness zones, water and bloom months and color
- ascfg.orgAssociation of Specialty Cut Flower Growers, 2007 Seed Trial Report (T...height, hardiness zones, bloom months and color and soil
- benary.comBenary (Ernst Benary Samenzucht, the breeder; its web page for the Blu...height, hardiness zones, bloom months and color and soil
- Chicago Botanic GardenGlencoe, Illinois; its page for this cultivarhardiness zones, sun, water and bloom months and color
- diggingdog.comDigging Dog Nursery (retail and mail-order nursery, Albion, California)height, spread, hardiness zones and bloom months and color
- farmerbailey.comFarmer Bailey (plug broker for cut-flower growers; its Plug Connection...hardiness zones, bloom months and color, diseases and pests
- fedcoseeds.comFedco Seeds (seed cooperative, Clinton, Maine)height, hardiness zones, bloom months and color and pests
- Plant Delights Nurserymail-order nursery; an archive pageheight, hardiness zones, water and bloom months and color
- redbuttegarden.orgRed Butte Garden and Arboretum (the University of Utah's botanical gar...height, spread, hardiness zones, sun and water
- romencegardens.comRomence Gardens (garden center and mail-order store, Grand Rapids, Mic...height, spread, hardiness zones and bloom months and color
- ascfg.orgAssociation of Specialty Cut Flower Growers, 2006 ASCFG Cut Flower See...height, bloom months and color and diseases
- fleuroselect.comFleuroselect (the ornamental-plant industry's trial and award organiza...height, spread and bloom months and color
- flowerbulbs.cornell.eduCornell University, The 2009 Cut Flower Trials (H. C. Wien, Department...height, bloom months and color and diseases
- friendsschoolplantsale.comFriends School Plant Sale (an annual plant sale at the Minnesota State...height, bloom months and color and toxicity
- plants.platthillnursery.comNetPS Plant Finder, as served by Platt Hill Nursery (garden centers at...height, spread, hardiness zones and water
- Sooner Plant Farmmail-order nursery, Park Hill, Oklahoma; photo credited to Walters Gar...height, spread, hardiness zones and diseases
- sugarcreekgardens.comSugar Creek Gardens (retail nursery, St. Louis, Missouri area)height, spread, hardiness zones and water
- swiftgreenhouses.comSwift Greenhouses (wholesale perennial plug grower, Gilman, Iowa)height, spread, hardiness zones and water
- utgardens.tennessee.eduUT Gardens, the State Botanical Garden of Tennessee: July 2013 Plant o...sun, bloom months and color and diseases
- Walters Gardenswholesale grower, Zeeland, Michigan; its culture sheet for Eryngium, a...water, bloom months and color and diseases
- arboretum.ucdavis.eduFriends of the UC Davis Arboretum and Public Garden, October 13, 2018...water and bloom months and color
- benary.comBenary (Ernst Benary Samenzucht, the breeder; its FastraX Collection b...height and bloom months and color
- buddgardens.comBudd Gardens (retail perennial nursery, Ottawa, Ontario; image credite...height, spread and hardiness zones
- cutflowers.ces.ncsu.eduNC State Extension, Cut Flowers: the 2006 ASCFG trial page for this cu...bloom months and color and trait tags
- uprisingorganics.comUprising Seeds (organic seed farm, Bellingham, Washington)water and bloom months and color
- benary.comBenary (Ernst Benary Samenzucht, the breeder; its technical guide for...height and hardiness zones
- hazzardsgreenhouse.comHazzard's Seeds (wholesale seed house, Deford, Michigan; its Eryngium...height and hardiness zones
- Plants For A Futurespecies page, Eryngium planumsun and toxicity
- ufseeds.comUrban Farmer (seed store; its description is Johnny's text)height and hardiness zones
- friendsschoolplantsale.comFriends School Plant Sale, 2026 catalog, perennials section, a PDFtoxicity
- Internet Archive (archived page)Benary (Ernst Benary Samenzucht, the breeder; its own product page for...height
- Internet Archive (archived page)Benary (Ernst Benary Samenzucht, the breeder; its own page for the Blu...height
- Iowa State University Extensiona list that names the genuswater
- Iowa State University Extensiona list that names the genuspests
- ipm-cahnr.media.uconn.eduUConn Extension (University of Connecticut), Deer Management: Strategi...pests
- Johnny's Selected Seedsits crop text for Eryngium planumhardiness zones
- Penn State Extensiona list that names the genuswater
- Proven Winnersthe brand's page for this plant; it prints Walters Gardens' figures an...water
- RHSthe genus Eryngiumsun
How the checking works, and what each standard covers, is on the verified plants page.
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Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.