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When to plant Hyacinths in Winnebago County County,

Plant Hyacinths in Winnebago County County from mid-spring to late spring in spring. Winnebago County County sits in USDA Zone 5b, with last frost around April 26 and first frost on October 12. A second sowing from August 31 to September 14 extends the harvest into fall.

When to Plant Hyacinths in Winnebago County, IL

Winnebago County, Illinois Zone 5b June

What to do in June

Here's what deserves your attention in Winnebago County, Illinois this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost April 26
Avg. first frost October 12
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 15.1 hrs

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Hyacinths (Hyacinthus orientalis) fill the spring garden with an almost overwhelming fragrance — a single cluster of blooms can perfume an entire yard. Dense, upright spikes of waxy florets in shades of purple, pink, blue, white, and red emerge in mid-spring, bridging the gap between the first crocus and the tulip peak. Though bulbs bloom most spectacularly in their first year, established plantings continue to produce graceful, less-dense flower spikes for several years. Deer and rabbits avoid them due to toxic alkaloids.

Winnebago County, Illinois is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 12, giving you a growing season of approximately 169 days.

At an elevation of 1,318 feet, Winnebago County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Hyacinths during the growing season.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Winnebago County, IL (Zone 5b) Moderate season
169 days
Last Spring Frost April 26
169 growing days
First Fall Frost October 12
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Winnebago County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7.3

Drainage

Well Drained

Hyacinths Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 21 🌸 Bloom from: Mar 31
Recommended (50%) ✓ Fits season
Transplant: Apr 26 🌸 Bloom from: Apr 5
Safe Start (90%) ✓ Fits season
Transplant: May 10 🌸 Bloom from: Apr 19

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Winnebago County

How your county's soil matches Hyacinths's growing requirements.

Soil pH

Your soil pH (6.3–7.3) is within Hyacinths's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Winnebago County is excellent for Hyacinths — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) — Hyacinths will thrive.

How to Plant Hyacinths

6"
Planting Depth
6"
Between Plants
8"
Between Rows

Fall planting: Sow 6 weeks before your first frost date for a fall harvest.

Succession Planting Hyacinths

15
successive plantings in your 169-day season

Sow every 1.6 weeks. Last sowing by Sep 14 to harvest before frost.

For a dedicated fall crop, sow by Aug 31.

Hyacinths Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Hyacinths

Hyacinths needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Hyacinths Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 3.9" 0" ✅ Rainfall sufficient
May 2.2" 4.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4" 0" ✅ Rainfall sufficient
Aug 2.2" 3.8" 0" ✅ Rainfall sufficient
Sep 2.2" 3.6" 0" ✅ Rainfall sufficient
Oct 2.2" 2.8" 0" ✅ Rainfall sufficient
Nov 2.8" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Winnebago County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hyacinths Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Hyacinths needs ~320 GDD — county provides 2,577 GDD Excellent fit

Hyacinths Planting Timeline — Winnebago County, IL

Hyacinths Planting Calendar

Activity When Date Range
Bloom August 10 Aug 10 – Sep 7
Fall Sowing August 31 Aug 31 – Sep 14

Plant 6" deep · 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July
August Fall Sowing Bloom
September Fall Sowing Bloom
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

14–28 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

169 days in Winnebago County

Growing Tips for Hyacinths in Winnebago County

Direct sow Hyacinths outdoors after April 26 in Winnebago County when soil has warmed and frost danger has passed.

Your generous 169.0-day season in Winnebago County allows multiple plantings of Hyacinths. Sow every 7.0 days for continuous harvest.

General growing tips

Plant bulbs 6 inches deep and 6 inches apart in fall, when soil drops below 60°F. Wear gloves when handling — bulb sap causes contact dermatitis in some people. After bloom, deadhead the spent spike but leave the strap-like foliage until it yellows naturally. For naturalizing, plant at 6–8 inch spacings and allow clumps to mature undisturbed. In zones 7b–9b, treat bulbs as annuals or use pre-chilled stock; performance after year 1 declines in warm-winter zones. For forcing indoors, chill bulbs 10–12 weeks then bring into warmth.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hyacinths in Winnebago County, IL?

Winnebago County is in Zone 5b with an average last frost of April 26. Plan your Hyacinths planting based on this frost date — see the calendar above for exact timing.

What planting zone is Winnebago County, IL?

Winnebago County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 12.

When should I plant Hyacinths in Winnebago County County, ?

In Winnebago County County, , plant Hyacinths after the last frost (around April 26) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Winnebago County County, for Hyacinths?

Winnebago County County sits in USDA Zone 5b. Hyacinths grows reliably in zones 3a through 9b, so it's a good fit here.

Can Hyacinths grow in Winnebago County County's climate?

Yes — Hyacinths grows well in Winnebago County County's temperate climate. Winnebago County County averages a 169-day frost-free season, with last frost around April 26 and first frost around October 12.

🌱

Your Winnebago County Garden Planner — Free

A 22-page printable planner built for Winnebago County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Winnebago County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.