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When to plant Dianthus in Jackson County, CO

Jackson County sits in cold Zone 4b. Plant Dianthus May 23–June 13 for the single annual harvest; the September 4 first frost closes the window.

When to Plant Dianthus in Jackson County, CO

Jackson County, Colorado Zone 4b August

Your August game plan for Jackson County, Colorado

A quick August briefing for Jackson County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost June 13
Avg. first frost September 4
Soil temp (4") 56°F
Watering High
Pest pressure Moderate
Daylight 13.6 hrs
  1. Get dianthus seeds going inside

    You're about 3 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Basket week: dianthus

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before September arrives, get these ready
  • 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.

Jackson County, Colorado is in USDA Zone 4b. The average last spring frost is June 13 and the first fall frost is September 4, giving you a growing season of approximately 83 days.

At an elevation of 5,388 feet, Jackson County receives approximately 20.9 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Dianthus to ensure they mature before fall.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Jackson County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 13
83 growing days
First Fall Frost September 4

Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Dianthus Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 6 Transplant: Jun 1 🌸 Bloom: Jul 20 – Sep 28
Recommended (50%) ✗ May not fit
Start indoors: Apr 11 Transplant: Jun 6 🌸 Bloom: Jul 25 – Oct 3
Safe Start (90%) ✗ May not fit
Start indoors: Apr 23 Transplant: Jun 18 🌸 Bloom: Aug 6 – Oct 15

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 Jackson County

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

Soil pH

Your soil pH (6.6–8.1) overlaps with Dianthus's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Dianthus.

How to Plant Dianthus

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

Dianthus Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.6" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 2.2" 0" ❄️ Dormant
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 1.7" 0.5" 💧 Light watering
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 1.4" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Jackson 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 ~700 GDD — county provides 830 GDD Good fit

Dianthus Planting Timeline — Jackson County, CO

Dianthus Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 – Apr 25
Transplant Outdoors June 6 Jun 6 – Jun 20
Direct Sow May 23 May 23 – Jun 13
Bloom July 25 Jul 25 – Oct 3

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

83 days in Jackson County

Growing Tips for Dianthus in Jackson County

Direct sow Dianthus outdoors after June 13 in Jackson County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Jackson County is tight for Dianthus (60.0-80.0 days to maturity). Start indoors and choose early-maturing varieties.

Jackson County receives only 21" 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 Jackson County, CO?

Jackson County is in Zone 4b with an average last frost of June 13. Plan your Dianthus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, CO?

Jackson County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 13 and first fall frost is September 4.

When should I plant Dianthus in Jackson County, CO?

In Jackson County, CO, plant Dianthus after the last frost (around June 13) and before the first frost (around September 4). Best results when soil holds above 50°F.

What growing zone is Jackson County, CO for Dianthus?

Jackson County sits in USDA Zone 4b. Dianthus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Dianthus grow in Jackson County's climate?

Yes — Dianthus grows well in Jackson County's temperate climate. Jackson County averages a 83-day frost-free season, with last frost around June 13 and first frost around September 4.

🌱

Your Jackson County Garden Planner — Free

A 22-page printable planner built for Jackson County (Zone 4b). 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 Jackson County, CO. Local conditions may vary. Last updated: August 2026.

Sources & credits

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