Illustration
Blue Jacket
Hyacinthus 'Blue Jacket'
Blue Jacket blooms from March through April.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Blue Jacket
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 4–8. Expect it to reach about 10 in tall and 5 in wide at maturity, in roughly 1 year (not yet checked).
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. 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 Jacket
Blue Jacket is a fall-planted bulb: get it in the ground 6 to 8 weeks before the ground freezes, typically September or October in zone 6, the middle of its hardy zones 4 to 8. It pays you back the following March to April.
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 September. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Blue Jacket get?
10 intall5 ft 7 inan adult5 inwideSee Blue Jacket in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
Where these facts come from
Blue Jacket's height, spread, hardiness zones, sun and trait tags were checked against 13 published sources on July 29, 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.
- adrbulbs.comADR Bulbsheight, spread, hardiness zones, sun and trait tags
- easytogrowbulbs.comEasy To Grow Bulbsheight, spread, hardiness zones, sun and trait tags
- Missouri Botanical Gardenheight, spread, hardiness zones, sun and trait tags
- plants.gertens.comNetPS Plant Finder (via Gertens)height, spread, hardiness zones, sun and trait tags
- dutchbulbs.comVan Bourgondienheight, hardiness zones, sun and trait tags
- dutchgrown.comDutchGrownheight, hardiness zones, sun and trait tags
- Longfield Gardensheight, hardiness zones, sun and trait tags
- Plant Addictsheight, spread, hardiness zones and sun
- RHSheight, spread, sun and trait tags
- Brent and Becky's Bulbsheight, hardiness zones and sun
- colorblends.comColorblendsheight, hardiness zones and sun
- NC State ExtensionPlant Toolboxhardiness zones, sun and trait tags
- Van Engelenheight, hardiness zones and sun
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about Blue Jacket
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Toxic to dogs, cats and horses; all parts, and the bulb most of all. Eating it causes drooling, intense vomiting and diarrhea. per ASPCA
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.