When to Plant Sunflower in Lamb County, TX
Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.
Lamb County, Texas is in USDA Zone 7a. The average last spring frost is April 8 and the first fall frost is October 27, giving you a growing season of approximately 202 days.
At an elevation of 1,440 feet, Lamb County receives approximately 56.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Sunflower may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sunflower will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunflower root diseases.
Lamb County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.5-8.4
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 Lamb County
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (7.5–8.4) is more alkaline than Sunflower prefers (6.0–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Lamb County warms quickly in spring but drains fast. Sunflower will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Sunflower.
How to Plant Sunflower
Succession Planting Sunflower
Sow every 8 weeks. Last sowing by Jul 19 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Sunflower
Sunflower 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 | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.9" | 0" | ❄️ Dormant |
| Feb | — | 2.8" | 0" | ❄️ Dormant |
| Mar | — | 3.5" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2" | 0.2" | 💧 Light watering |
| May | 2.2" | 1.2" | 1" | 💧 Light watering |
| Jun | 2.2" | 2" | 0.2" | 💧 Light watering |
| Jul | 2.2" | 8.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 11.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 8.8" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.4" | 0" | ❄️ Dormant |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Lamb County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower 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.
Sunflower Planting Timeline — Lamb County, TX
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 18 | Feb 18 – Mar 4 |
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Direct Sow | April 15 | Apr 15 – May 6 |
| Harvest | July 1 | Jul 1 – Aug 19 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
202 days in Lamb County
Growing Tips for Sunflower in Lamb County
Direct sow Sunflower outdoors after April 08 in Lamb County when soil has warmed and frost danger has passed.
Sandy soil in Lamb County dries quickly — mulch Sunflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 96°F in Lamb County, provide afternoon shade for Sunflower and water deeply in the morning.
Common pests for Sunflower 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. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Lamb County, TX?
Lamb County is in Zone 7a with an average last frost of April 8. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lamb County, TX?
Lamb County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 8 and first fall frost is October 27.
Plan Your Garden with Confidence
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