When to Plant Cosmos in Caldwell County, TX
Your June planting checklist for Caldwell County, Texas
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Caldwell County, Texas.
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Harvest cosmos as they ripen
If you can't use it all right away, check the food-preservation section of your planner.
Get ahead of July
- 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.
Caldwell County, Texas is in USDA Zone 9a. The average last spring frost is February 27 and the first fall frost is December 1, giving you a growing season of approximately 277 days.
At an elevation of 3,482 feet, Caldwell County receives approximately 60.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Cosmos during the growing season. Clay soil retains moisture well for Cosmos, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.
Caldwell County Soil Profile
Soil Type
Clay
Soil pH
6.8-8.1
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 Caldwell County
How your county's soil matches Cosmos's growing requirements.
Soil pH
Your soil pH (6.8–8.1) overlaps with Cosmos's range (6.0–8.0), though not a perfect match.
Soil Texture
Heavy clay soil (43% clay) in Caldwell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (3.3%). Annual compost additions will help Cosmos.
How to Plant Cosmos
Succession Planting Cosmos
Sow every 6.9 weeks. Last sowing by Sep 02 to harvest before frost.
Cosmos Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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" | 2.1" | 0.1" | 💧 Light watering |
| Mar | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 9.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Dec | 2.2" | 1.5" | 0.7" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Caldwell 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 — Caldwell County, TX
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 30 | Jan 30 – Feb 13 |
| Transplant Outdoors | January 30 | Jan 30 – Feb 13 |
| Direct Sow | January 30 | Jan 30 – Feb 20 |
| Bloom | April 10 | Apr 10 – Sep 25 |
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 Transplant Outdoors Direct Sow |
| March | — |
| 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: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
277 days in Caldwell County
Growing Tips for Cosmos in Caldwell County
Direct sow Cosmos outdoors after February 27 in Caldwell County when soil has warmed and frost danger has passed.
With Caldwell County's clay soil (43% clay), work in 3-4 inches of compost before planting Cosmos. Avoid tilling when soil is wet to prevent compaction.
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 Caldwell County, TX?
Caldwell County is in Zone 9a with an average last frost of February 27. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Caldwell County, TX?
Caldwell County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 27 and first fall frost is December 1.
Your Caldwell County Garden Planner — Free
A 22-page printable planner built for Caldwell County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.