When to Plant Cosmos in Calhoun County, TX
Your June gardening checklist
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.
-
It's harvest week for cosmos
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
To set up a strong July, finish these tasks
- First harvests: cosmos
Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.
Calhoun County, Texas is in USDA Zone 9b. The average last spring frost is February 16 and the first fall frost is December 7, giving you a growing season of approximately 294 days.
At an elevation of 215 feet, Calhoun County receives approximately 59.5 inches of rainfall annually with predominantly loam soil. Summer highs average 99°F, so Cosmos may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.
Calhoun County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.8
Drainage
Well Drained
Cosmos 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 Calhoun County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (6.2–7.8) is within Cosmos's preferred range (6.0–8.0).
Soil Texture
The loam soil in Calhoun County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Cosmos.
How to Plant Cosmos
Succession Planting Cosmos
Sow every 6.9 weeks. Last sowing by Sep 08 to harvest before frost.
Cosmos Water Budget
Monthly Watering Guide for Cosmos
Cosmos 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 | Cosmos Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.7" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 8.5" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 9.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7.3" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Dec | 2.2" | 1.9" | 0.3" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Calhoun County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos 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.
Cosmos Planting Timeline — Calhoun County, TX
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 19 | Jan 19 – Feb 2 |
| Transplant Outdoors | January 12 | Jan 12 – Jan 26 |
| Direct Sow | January 12 | Jan 12 – Feb 2 |
| Bloom | March 23 | Mar 23 – Sep 21 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Start Indoors Direct Sow |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–8 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
294 days in Calhoun County
Growing Tips for Cosmos in Calhoun County
Direct sow Cosmos outdoors after February 16 in Calhoun County when soil has warmed and frost danger has passed.
With summer highs reaching 99°F in Calhoun County, provide afternoon shade for Cosmos and water deeply in the morning.
Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Cosmos in Other Locations
Frequently Asked Questions
When should I plant Cosmos in Calhoun County, TX?
Calhoun County is in Zone 9b with an average last frost of February 16. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Calhoun County, TX?
Calhoun County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 16 and first fall frost is December 7.
Your Calhoun County Garden Planner — Free
A 22-page printable planner built for Calhoun County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.