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When to plant Dianthus in Jerome County, ID

In Jerome County, Dianthus is a single-season spring crop — there's no second fall window. Plant April 12–May 3 for an 60–80-day harvest, finishing well before the October 4 first frost.

When to Plant Dianthus in Jerome County, ID

Jerome County, Idaho Zone 6b June

Your June game plan for Jerome County, Idaho

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 10
Avg. first frost October 4
Soil temp (4") 55°F
Watering Critical
Pest pressure High
Daylight 15.1 hrs
  1. It's harvest week for dianthus

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

July will be here before you know it — start on
  • Starting indoors: dianthus
  • First harvests: dianthus

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China pinks (Dianthus chinensis) are a reliable cool-season annual offering fringed blooms with a spicy-sweet clove fragrance. They perform best in the cool temperatures of spring and fall, providing vivid color in beds and borders when summer annuals haven't kicked in yet. In warmer zones they are grown as fall–winter–spring annuals. The compact mounding habit and clean foliage make them excellent edging and container plants.

Jerome County, Idaho is in USDA Zone 6b. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 6,306 feet, Jerome County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Dianthus during the growing season. With low rainfall, drip irrigation is essential for growing Dianthus successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Jerome County, ID (Zone 6b) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4

Jerome County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.9

Drainage

Well Drained

Dianthus Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🌸 Bloom: May 29 – Aug 28
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🌸 Bloom: Jun 7 – Sep 6
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Apr 9 Transplant: May 14 🌸 Bloom: Jul 2 – Oct 1

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 Jerome County

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

Soil pH

Your soil pH (6.8–7.9) overlaps with Dianthus's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Jerome County is excellent for Dianthus — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Dianthus.

How to Plant Dianthus

0.1"
Planting Depth
8"
Between Plants
10"
Between Rows

Succession Planting Dianthus

2
successive plantings in your 147-day season

Sow every 6.9 weeks. Last sowing by Jul 16 to harvest before frost.

Dianthus Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 179 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Dianthus

Dianthus 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 Dianthus Needs Rainfall You Supplement Action
Jan 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 2.2" 1.5" 0.7" 💧 Light watering
Jun 2.2" 1" 1.2" 🚿 Regular watering
Jul 2.2" 1.2" 1" 💧 Light watering
Aug 2.2" 1.3" 0.9" 💧 Light watering
Sep 2.2" 1.1" 1.1" 🚿 Regular watering
Oct 2.2" 1.1" 1.1" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

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

Dianthus 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.

Dianthus needs ~962 GDD — county provides 2,021 GDD Excellent fit

Dianthus Planting Timeline — Jerome County, ID

Dianthus Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 12 Apr 12 – May 3
Bloom June 7 Jun 7 – Sep 6

Plant 0.1" deep · 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

147 days in Jerome County

Growing Tips for Dianthus in Jerome County

Direct sow Dianthus outdoors after May 10 in Jerome County when soil has warmed and frost danger has passed.

Jerome County receives only 14" of rain annually. Dianthus needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 8–10 weeks before last frost for spring transplants, or direct-sow in early spring as soon as soil can be worked — seeds tolerate light frost. Can also be direct-sown in late summer for fall bloom. Plant in full sun with excellent drainage; poorly drained soil causes crown rot. Deadhead regularly to extend bloom. In zones 8–10, plant as a fall annual for winter– spring color; plants decline in summer heat.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Dianthus in Jerome County, ID?

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

What planting zone is Jerome County, ID?

Jerome County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 10 and first fall frost is October 4.

When should I plant Dianthus in Jerome County, ID?

In Jerome County, ID, plant Dianthus after the last frost (around May 10) and before the first frost (around October 4). Best results when soil holds above 50°F.

What growing zone is Jerome County, ID for Dianthus?

Jerome County sits in USDA Zone 6b. Dianthus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Dianthus grow in Jerome County's climate?

Yes — Dianthus grows well in Jerome County's temperate climate. Jerome County averages a 147-day frost-free season, with last frost around May 10 and first frost around October 4.

🌱

Your Jerome County Garden Planner — Free

A 22-page printable planner built for Jerome County (Zone 6b). 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 Jerome County, ID. Local conditions may vary. Last updated: June 2026.

Sources & credits

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