When to plant Dianthus in Summit County, CO
Summit County's short 80-day growing season means one Dianthus planting between May 19 and June 9. No fall crop in Zone 5a.
When to Plant Dianthus in Summit County, CO
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.
Summit County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.
At an elevation of 7,005 feet, Summit County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Dianthus to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Dianthus successfully. Mulch heavily to conserve soil moisture.
Summit County Soil Profile
Soil Type
Loam
Soil pH
6.8-8
Drainage
Well Drained
Monthly Watering Guide for Dianthus
Dianthus needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Dianthus Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | — | 1.8" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Summit County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Dianthus Planting Timeline — Summit County, CO
Dianthus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 14 | Apr 14 – Apr 28 |
| Transplant Outdoors | June 2 | Jun 2 – Jun 16 |
| Direct Sow | May 19 | May 19 – Jun 9 |
| Bloom | July 21 | Jul 21 – Oct 6 |
Plant 0.1" deep · 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
Low — drought tolerant
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5a
📆 Growing Season
80 days in Summit County
Growing Tips for Summit County
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 →
Dianthus in Other Locations
Frequently Asked Questions
When should I plant Dianthus in Summit County, CO?
Summit County is in Zone 5a with an average last frost of June 16. Plan your Dianthus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Summit County, CO?
Summit County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 4.
When should I plant Dianthus in Summit County, CO?
In Summit County, CO, plant Dianthus after the last frost (around June 16) and before the first frost (around September 4). Best results when soil holds above 50°F.
What growing zone is Summit County, CO for Dianthus?
Summit County sits in USDA Zone 5a. Dianthus grows reliably in zones 3a through 10b, so it's a good fit here.
Can Dianthus grow in Summit County's climate?
Yes — Dianthus grows well in Summit County's temperate climate. Summit County averages a 80-day frost-free season, with last frost around June 16 and first frost around September 4.
Your Summit County Garden Planner — Free
A 22-page printable planner built for Summit County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.