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When to plant Ranunculus in Delavan, IL

Delavan's short 179-day growing season means one Ranunculus planting between April 19 and May 3. No fall crop in Zone 6a.

When to Plant Ranunculus in Delavan, IL

Tazewell County, Illinois Zone 6a July

Tazewell County, Illinois gardeners: here's your July plan

Welcome to July in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 19
Avg. first frost October 15
Soil temp (4") 75°F
Watering Low
Pest pressure High
Daylight 14.6 hrs

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Persian ranunculus (Ranunculus asiaticus) produces multi-petaled blooms that rival roses in intricacy and lushness, in a warm palette of reds, oranges, yellows, pinks, and whites. A cornerstone of the specialty cut flower industry, ranunculus produces long, strong stems ideal for bouquets and arrangements. As a cool-season corm, it performs best in the mild shoulder seasons — planted in fall in warm-winter zones, or in early spring where summers arrive quickly. The 'Elegance', 'Amandine', and 'Tecolote' strains are favorites for both home gardens and commercial growers.

Delavan, Illinois is in USDA Zone 6a. The average last spring frost is April 19 and the first fall frost is October 15, giving you a growing season of approximately 179 days.

At an elevation of 1,006 feet, Tazewell County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Ranunculus during the growing season.

Bulb Blooms in Spring Pollinator-friendly Good for cutting
Delavan, IL (Zone 6a) Moderate season
179 days
Last Spring Frost April 19
179 growing days
First Fall Frost October 15

Delavan Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.9

Drainage

Well Drained

Ranunculus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (108 days to spare)
Start indoors: Mar 3 Transplant: Apr 14 🌸 Bloom: May 26 – Jun 23
Recommended (50%) ✓ Fits season (109 days to spare)
Start indoors: Mar 8 Transplant: Apr 19 🌸 Bloom: May 31 – Jun 28
Safe Start (90%) ✓ Fits season (108 days to spare)
Start indoors: Mar 22 Transplant: May 3 🌸 Bloom: Jun 14 – Jul 12

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 Delavan

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

Soil pH

Your soil pH (6.3–6.9) is more alkaline than Ranunculus prefers (6.0–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Ranunculus will thrive.

How to Plant Ranunculus

2"
Planting Depth
6"
Between Plants
8"
Between Rows

Ranunculus Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 98 gal / 100 sq ft

Monthly Watering Guide for Ranunculus

Ranunculus needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Ranunculus Needs Rainfall You Supplement Action
Jan 1.9" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 5.2" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 4.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Ranunculus 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.

Ranunculus needs ~1,601 GDD — county provides 2,729 GDD Excellent fit

Ranunculus Planting Timeline — Delavan, IL

Ranunculus Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors April 19 Apr 19 – May 3
Bloom May 31 May 31 – Jun 28

Plant 2" deep · 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors
May Transplant Outdoors Bloom
June Bloom
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

179 days in Tazewell County

Growing Tips for Ranunculus in Delavan

Direct sow Ranunculus outdoors after April 19 in Tazewell County when soil has warmed and frost danger has passed.

General growing tips

Pre-soak corms (which look like small octopus tentacles) in cool water for 2–4 hours before planting; do not over-soak. Plant with tentacles pointing downward, 1–2 inches deep and 6 inches apart. Ranunculus demand excellent drainage — they rot in soggy soil. In fall-planting zones (7+), plant October–November and allow to root through mild winter; blooms arrive in March–May. In zones 6, start corms indoors in late winter and transplant out after last frost for a late-spring bloom. Keep soil consistently moist but never waterlogged during growth. After foliage yellows (post-bloom), stop watering, let corms dry, lift them, and store in a cool dry place until replanting. In zones 8b–10b, corms can often be left in ground year-round.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

When should I plant Ranunculus in Delavan, IL?

In Delavan, IL, plant Ranunculus after the last frost (around April 19) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Delavan, IL for Ranunculus?

Delavan sits in USDA Zone 6a. Ranunculus grows reliably in zones 6a through 10b, so it's a good fit here.

Can Ranunculus grow in Delavan's climate?

Yes — Ranunculus grows well in Delavan's temperate climate. Delavan averages a 179-day frost-free season, with last frost around April 19 and first frost around October 15.

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Your Tazewell County Garden Planner — Free

A 22-page printable planner built for Tazewell County (Zone 6a). 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 Tazewell County, IL. Local conditions may vary. Last updated: July 2026.