When to Plant Carrots in Starr County, TX
What to do in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
Carrots are a popular root vegetable available in orange, purple, white, and yellow varieties. They are rich in beta-carotene and have a sweet, earthy flavor.
Starr County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 16, giving you a growing season of approximately 316 days.
At an elevation of 2,451 feet, Starr County receives approximately 55.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98°F, so Carrots may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Carrots root diseases.
Starr County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.5
Drainage
Well Drained
Plant 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 Starr County
How your county's soil matches Carrots's growing requirements.
Soil pH
Your soil pH (6.8–7.5) is more alkaline than Carrots prefers (6.0–6.8). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Starr County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Carrots.
How to Plant Carrots
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Carrots
Sow every 6.9 weeks. Last sowing by Sep 27 to harvest before frost.
For a dedicated fall crop, sow by Oct 21.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Carrots
Carrots needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.
| Month | Carrots Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 3.5" | 1.9" | 1.6" | 💧 Light watering |
| Mar | 3.5" | 3.4" | 0.1" | 💧 Light watering |
| Apr | 3.5" | 6.6" | 0" | ✅ Rainfall sufficient |
| May | 3.5" | 8.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3.5" | 7.6" | 0" | ✅ Rainfall sufficient |
| Jul | 3.5" | 7" | 0" | ✅ Rainfall sufficient |
| Aug | 3.5" | 6.4" | 0" | ✅ Rainfall sufficient |
| Sep | 3.5" | 4.9" | 0" | ✅ Rainfall sufficient |
| Oct | 3.5" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
| Dec | 3.5" | 1.6" | 1.9" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Starr County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Carrots 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.
Carrots Planting Timeline — Starr County, TX
Carrots Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | January 13 | Jan 13 – Feb 3 |
| Harvest | March 17 | Mar 17 – Apr 21 |
| Fall Sowing | October 21 | Oct 21 – Nov 4 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Direct Sow |
| February | Direct Sow |
| March | Harvest |
| April | Harvest |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | Fall Sowing |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.8"/week · Only during dry spells
📅 Days to Maturity
60–80 days
🧪 Soil pH
Needs 6–6.8 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
316 days in Starr County
Growing Tips for Carrots in Starr County
Direct sow Carrots outdoors after February 03 in Starr County when soil has warmed and frost danger has passed.
With summer highs reaching 98°F in Starr County, provide afternoon shade for Carrots and water deeply in the morning.
Common pests for Carrots in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly in loose, stone-free soil for straight roots. Keep soil moist until germination which can take 2-3 weeks. Thin seedlings to 2 inches apart.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.
Carrots in Other Locations
Frequently Asked Questions
When should I plant Carrots in Starr County, TX?
Starr County is in Zone 9b with an average last frost of February 3. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.
What planting zone is Starr County, TX?
Starr County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 16.
Your Starr County Garden Planner — Free
A 24-page printable planner built for Starr 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.