When to Plant Coreopsis in Jefferson County, TX
Your June planting checklist for Jefferson County, Texas
Your Jefferson County, Texas garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.
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Harvest coreopsis as they ripen
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
July prep starts now
- First harvests: coreopsis
Coreopsis (Tickseed) is a cheerful, long-blooming native perennial that produces a continuous flush of bright yellow, gold, or bi-colored daisy-like flowers from early summer well into fall. One of the most reliable cut-and-come-again bloomers in the perennial garden, it thrives in hot, dry, sunny conditions and poor soil where many competitors struggle. An invaluable nectar source for native bees and butterflies, and a butterfly host plant for several species.
Jefferson County, Texas is in USDA Zone 9b. The average last spring frost is February 13 and the first fall frost is December 6, giving you a growing season of approximately 296 days.
At an elevation of 349 feet, Jefferson County receives approximately 64.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 101°F, so Coreopsis may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Coreopsis will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Coreopsis root diseases.
Jefferson County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.4-6.5
Drainage
Well Drained
Coreopsis 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 Jefferson County
How your county's soil matches Coreopsis's growing requirements.
Soil pH
Your soil pH (5.4–6.5) overlaps with Coreopsis's range (5.5–7.5), though not a perfect match.
Soil Texture
Sandy soil in Jefferson County warms quickly in spring but drains fast. Coreopsis will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Coreopsis.
How to Plant Coreopsis
Succession Planting Coreopsis
Sow every 6.9 weeks. Last sowing by Sep 17 to harvest before frost.
Coreopsis Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Coreopsis
Coreopsis 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 | Coreopsis Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Mar | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.3" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 9.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 10.7" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 8.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Dec | 2.2" | 1.6" | 0.6" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Coreopsis 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.
Coreopsis Planting Timeline — Jefferson County, TX
Coreopsis Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 19 | Dec 19 – Jan 2 |
| Transplant Outdoors | January 30 | Jan 30 – Feb 13 |
| Direct Sow | January 23 | Jan 23 – Feb 13 |
| Bloom | March 27 | Mar 27 – Aug 28 |
Plant 0.1" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
296 days in Jefferson County
Growing Tips for Coreopsis in Jefferson County
Direct sow Coreopsis outdoors after February 13 in Jefferson County when soil has warmed and frost danger has passed.
Sandy soil in Jefferson County dries quickly — mulch Coreopsis with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 101°F in Jefferson County, provide afternoon shade for Coreopsis and water deeply in the morning.
Common pests for Coreopsis in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8–10 weeks before last frost or direct sow after last frost. Seeds germinate easily without stratification. Thrives in poor to average, well-drained soil — rich soil promotes foliage over flowers. Drought tolerant once established; overwatering is the most common mistake. Deadhead spent blooms to maintain continuous flowering through the season. Shear plants by one-third in midsummer for a fresh flush of late-season blooms. Year 2+ plants bloom most heavily. Divide every 2–3 years in early spring to rejuvenate crowded clumps.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Coreopsis in Other Locations
Frequently Asked Questions
When should I plant Coreopsis in Jefferson County, TX?
Jefferson County is in Zone 9b with an average last frost of February 13. Plan your Coreopsis planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jefferson County, TX?
Jefferson County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 13 and first fall frost is December 6.
Your Jefferson County Garden Planner — Free
A 22-page printable planner built for Jefferson 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.