When to Plant Cosmos in Lee County, TX
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.
Lee County, Texas is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 30, giving you a growing season of approximately 275 days.
At an elevation of 1,174 feet, Lee County receives approximately 59.1 inches of rainfall annually with predominantly clay soil. Summer highs average 97°F, so Cosmos may need afternoon shade and extra watering during peak heat. 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.
Lee County Soil Profile
Soil Type
Clay
Soil pH
7.1-8.2
Drainage
Well Drained
Monthly Watering Guide for Cosmos
Cosmos needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Cosmos Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Mar | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 8.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 9.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 7.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Dec | — | 1.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Lee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos Planting Timeline — Lee County, TX
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 31 | Jan 31 – Feb 14 |
| Transplant Outdoors | January 31 | Jan 31 – Feb 14 |
| Direct Sow | January 31 | Jan 31 – Feb 21 |
| Bloom | April 11 | Apr 11 – Sep 26 |
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
Low — drought tolerant
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–8 · Your soil: N/A
🗺️ USDA Zone
Zone 9a
📆 Growing Season
275 days in Lee County
Growing Tips for Lee County
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 Lee County, TX?
Lee County is in Zone 9a with an average last frost of February 28. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lee County, TX?
Lee County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 30.
Your Lee County Garden Planner — Free
A 22-page printable planner built for Lee 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.