When to plant Dianthus in Williamson County, IL
For Williamson County, gardeners: plant Dianthus March 6 through March 27 once soil reads 50°F.
When to Plant Dianthus in Williamson County, IL
Your July planting checklist for Williamson County, Illinois
July is a pivotal month for Williamson County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Basket week: dianthus
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong August, finish these tasks
- First harvests: dianthus
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.
Williamson County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 20, giving you a growing season of approximately 193 days.
At an elevation of 1,253 feet, Williamson County receives approximately 38.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Dianthus during the growing season.
Williamson County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
Drainage
Well Drained
Dianthus Planting Risk Windows
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 Williamson County
How your county's soil matches Dianthus's growing requirements.
Soil pH
Your soil pH (6.2–7.2) is within Dianthus's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Williamson County is excellent for Dianthus — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Dianthus will thrive.
How to Plant Dianthus
Succession Planting Dianthus
Sow every 6.9 weeks. Last sowing by Aug 01 to harvest before frost.
Dianthus Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.4" | 0" | ❄️ Dormant |
| Dec | — | 2.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Williamson 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 Planting Timeline — Williamson County, IL
Dianthus Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 13 | Feb 13 – Feb 27 |
| Transplant Outdoors | March 20 | Mar 20 – Apr 3 |
| Direct Sow | March 6 | Mar 6 – Mar 27 |
| Bloom | May 8 | May 8 – Aug 7 |
Plant 0.1" deep · 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| 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: ideal
🗺️ USDA Zone
Zone 7a
📆 Growing Season
193 days in Williamson County
Growing Tips for Dianthus in Williamson County
Direct sow Dianthus outdoors after April 10 in Williamson County when soil has warmed and frost danger has passed.
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 →
Dianthus in Other Locations
Frequently Asked Questions
When should I plant Dianthus in Williamson County, IL?
Williamson County is in Zone 7a with an average last frost of April 10. Plan your Dianthus planting based on this frost date — see the calendar above for exact timing.
What planting zone is Williamson County, IL?
Williamson County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 20.
When should I plant Dianthus in Williamson County, IL?
In Williamson County, IL, plant Dianthus after the last frost (around April 10) and before the first frost (around October 20). Best results when soil holds above 50°F.
What growing zone is Williamson County, IL for Dianthus?
Williamson County sits in USDA Zone 7a. Dianthus grows reliably in zones 3a through 10b, so it's a good fit here.
Can Dianthus grow in Williamson County's climate?
Yes — Dianthus grows well in Williamson County's temperate climate. Williamson County averages a 193-day frost-free season, with last frost around April 10 and first frost around October 20.
Your Williamson County Garden Planner — Free
A 22-page printable planner built for Williamson County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.