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When to Plant Romanesco in Dallam County, TX

Dallam County, Texas Zone 6b May

What to do in May

May is a pivotal month for Dallam County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 26
Avg. first frost October 14
Soil temp (4") 54°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: romanesco

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

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Romanesco is a stunning brassica with a lime-green head composed of fractal-patterned spiraling florets. It has a nuttier, milder flavor than cauliflower.

Dallam County, Texas is in USDA Zone 6b. The average last spring frost is April 26 and the first fall frost is October 14, giving you a growing season of approximately 171 days.

At an elevation of 3,388 feet, Dallam County receives approximately 54.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Romanesco may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Romanesco will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Romanesco root diseases.

Dallam County, TX (Zone 6b) Moderate season
171 days
Last Spring Frost April 26
171 growing days
First Fall Frost October 14

Dallam County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Jul 6 – Aug 17
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jul 12 – Aug 23
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 24 – Sep 4

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 Dallam County

How your county's soil matches Romanesco's growing requirements.

Soil pH

Your soil pH (7.9–8.4) is more alkaline than Romanesco prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Dallam County warms quickly in spring but drains fast. Romanesco will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.1%). Add 2-3 inches of compost before planting Romanesco.

How to Plant Romanesco

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Romanesco

2
successive plantings in your 171-day season

Sow every 8.6 weeks. Last sowing by Jul 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 05.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Romanesco

Romanesco needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Romanesco Needs Rainfall You Supplement Action
Jan 4" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 1.7" 2.6" 🚿 Regular watering
May 4.3" 1" 3.3" 🚿 Regular watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 9.9" 0" ✅ Rainfall sufficient
Aug 4.3" 11.7" 0" ✅ Rainfall sufficient
Sep 4.3" 8" 0" ✅ Rainfall sufficient
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 3.3" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Dallam County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Romanesco 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.

Romanesco needs ~1,925 GDD — county provides 3,762 GDD Excellent fit

Romanesco Planting Timeline — Dallam County, TX

Romanesco Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 12 Apr 12 – May 3
Harvest July 12 Jul 12 – Aug 23
Fall Sowing August 5 Aug 5 – Aug 19

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Fall Sowing Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

171 days in Dallam County

Growing Tips for Romanesco in Dallam County

Direct sow Romanesco outdoors after April 26 in Dallam County when soil has warmed and frost danger has passed.

Sandy soil in Dallam County dries quickly — mulch Romanesco 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 Dallam County, provide afternoon shade for Romanesco and water deeply in the morning.

Common pests for Romanesco in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 5-7 weeks before transplanting. Provide consistent moisture and avoid temperature stress. Harvest when head is fully formed but before florets begin to separate.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Romanesco in Dallam County, TX?

Dallam County is in Zone 6b with an average last frost of April 26. Plan your Romanesco planting based on this frost date — see the calendar above for exact timing.

What planting zone is Dallam County, TX?

Dallam County, Texas is in USDA Hardiness Zone 6b. The average last spring frost is April 26 and first fall frost is October 14.

🌱

Your Dallam County Garden Planner — Free

A 24-page printable planner built for Dallam County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Dallam County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.