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When to plant Ranunculus in Boundary County, ID

Boundary County sits in cold Zone 6a. Plant Ranunculus May 10–May 24 for the single annual harvest; the September 22 first frost closes the window.

When to Plant Ranunculus in Boundary County, ID

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.

Boundary County, Idaho is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is September 22, giving you a growing season of approximately 135 days.

At an elevation of 5,105 feet, Boundary County receives approximately 21.1 inches of rainfall annually with predominantly 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
Boundary County, ID (Zone 6a) Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Boundary County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Ranunculus Planting Timeline — Boundary County, ID

Ranunculus Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Bloom June 21 Jun 21 – Jul 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

135 days in Boundary County

Growing Tips for Boundary County

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 →

Frequently Asked Questions

When should I plant Ranunculus in Boundary County, ID?

Boundary County is in Zone 6a with an average last frost of May 10. Plan your Ranunculus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boundary County, ID?

Boundary County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is September 22.

When should I plant Ranunculus in Boundary County, ID?

In Boundary County, ID, plant Ranunculus after the last frost (around May 10) and before the first frost (around September 22). Best results when soil holds above 50°F.

What growing zone is Boundary County, ID for Ranunculus?

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

Can Ranunculus grow in Boundary County's climate?

Yes — Ranunculus grows well in Boundary County's temperate climate. Boundary County averages a 135-day frost-free season, with last frost around May 10 and first frost around September 22.

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Your Boundary County Garden Planner — Free

A 22-page printable planner built for Boundary 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 Boundary County, ID. Local conditions may vary. Last updated: July 2026.

Sources & credits

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