Cold hardiness

Future

2050

2100

These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.

Now

Zone 6b

USDA

Published baseline for this location from 1991-2020.

Source: USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer

Well-suited

2050

Zone 7a

Plotwright

Projected zone for this same location in 2050 (2041-2070) using SSP3-7.0 (regional rivalry).

Well-suited

In plain terms: This location is in Zone 6b today. Its hardiness profile is cold winters, and coldest nights are typically around -3°F. By 2050, the projected hardiness zone is Zone 7a based on SSP3-7.0 (regional rivalry). That is a +0.5-zone shift from Zone 6b to Zone 7a by 2050.

✓

Well-suited today and still thriving in 2050.

Heat tolerance

Future

2050

2100

Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.

Loading AHS heat-zone data for this location...

Where this plant fits

Suitable across 40 ecoregions — 35 climate-resilient through 2070 · 5 suited today. Best matches first.

Appalachian mixed mesophytic forests

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Appalachian-Blue Ridge forests

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Arizona Mountains forests

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Blue Mountains forests

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Canadian Aspen forests and parklands

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Central Pacific Northwest coastal forests

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Central Tallgrass prairie

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Central-Southern Cascades Forests

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Colorado Rockies forests

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Cross-Timbers savanna-woodland

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What it needs

Conditions

Light

Full sun / Part shade

Water

Moderate water

Spacing

5"

Habit

Low spring-flowering bulb with a single dense flower spike over basal strap-shaped leaves

Care tips

•

Plant bulbs 4-6 inches deep and 4-6 inches apart in mid-fall for an April bloom; group 6-15 bulbs for the strongest fragrance and color mass.

•

Wear gloves when handling bulbs — the sap can cause contact dermatitis and allergic skin reactions.

•

Keep soil moist after planting and through spring growth, then taper off after bloom; deadhead spent spikes so the bulb stores energy instead of setting seed.

Lifecycle

Planting

Easily grown in average, medium-moisture, well-drained soils in full sun; prefers organically rich soils and tolerates some light shade (Missouri Botanical Garden PlantFinder). Plant bulbs 4-6 inches deep and 4-6 inches apart in mid-fall, in mass or in clusters of 6-15 bulbs. Wear gloves when planting — the bulbs can cause allergic skin reactions / contact dermatitis.

Transplanting

Lift and move bulbs after foliage yellows and the plant enters dormancy; replant promptly at the same 4-6 inch depth in fall.

Early growth

Keep soils moist immediately after planting to encourage root growth, and keep soils moist through the spring growing season (Missouri Botanical Garden PlantFinder).

Maturity

Spikes bloom in April; taper off moisture after bloom as bulbs head toward dormancy, and promptly remove spent flower spikes so plants do not expend energy on seed production. Flower quality typically declines after the first year, potentially requiring replacement every couple of years (Missouri Botanical Garden PlantFinder).

Propagation

Propagated from bulb offsets; commercial stock is produced by scoring or scooping the basal plate to force bulblets. Wear gloves when handling bulbs.

Pollination

Self-fertile

Garden hyacinths are grown for their spring flowers and propagated vegetatively from bulb offsets rather than seed, so pollination is not required for the display. NC State Extension Plant Toolbox lists the flowers as attracting bees, which visit the early-spring spikes for nectar.

Plants don't grow alone

Nectar forage

Bee

European honeybee (Apis mellifera)

NC State Extension Plant Toolbox lists the early-spring flowers as attracting bees; the European honey bee is a common visitor to hyacinth spikes for nectar in late winter to spring.

Nectar forage

Bee

Common eastern bumblebee (Bombus impatiens)

Bumble bees emerging in early spring forage on hyacinth nectar where ranges overlap; NC State Extension documents bees generally as attracted, without naming species.

For people

Toxic — do not consume

All parts of the common hyacinth are mildly toxic. NC State Extension Plant Toolbox rates the poison severity as Medium: "Toxic only if eaten in large quantities. Causes minor skin irritation... Also causes stomach cramps, salivation, vomiting, and diarrhea. Dermatitis after contact with cell sap... Bulbs contain the highest amount of toxin." The toxic principle is alkaloids such as lycorine, with poison parts including the flowers, leaves, roots, sap, seeds, and stems. Missouri Botanical Garden PlantFinder advises wearing gloves when planting bulbs to avoid possible allergic skin reactions.

Toxic parts

bulb, flowers, leaves, roots, sap, seeds, stems

Pet toxicity

ASPCA lists garden hyacinth (Hyacinthus orientalis) as toxic to dogs, cats, and horses; the bulbs are the most concentrated source of toxin.

Native range

AHS heat range

1-9

Climate notes

•

Missouri Botanical Garden PlantFinder lists Hyacinthus orientalis for USDA hardiness zones 4 to 8 in full sun and medium moisture, with low maintenance and showy, fragrant flowers blooming in April.

•

Missouri Botanical Garden PlantFinder notes the plant tolerates Rabbit and Black Walnut, and that flower quality typically declines after the first year; "No serious insect or disease problems. Bulb rot may occur in poorly drained soils."

•

NC State Extension Plant Toolbox adds the species is resistant to Black Walnut, Deer, Drought, and Rabbits, and attracts Bees.

•

Native to the eastern Mediterranean (not native to North America); grown across temperate gardens as a fall-planted spring bulb.

In the designer

Growth over time

4-7" tall · 3-6" spread

Often replanted with fresh bulbs every couple of years to restore the dense first-year spike.

Design roles: Border · Container · Focal point

Seasonal interest

Spring

Summer

Fall

Winter

Filled = the plant has seasonal interest · ▾ now = your current season

Common hyacinth

At a glance

Related products

Why it matters

Cold hardiness

Heat tolerance

Where this plant fits

What it needs

Lifecycle

Pollination

Plants don't grow alone

For people

Native range

Climate notes

In the designer

Seasonal interest

Sources & citations