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When to Plant Cauliflower in Smyth County, VA

Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

Smyth County, Virginia is in USDA Zone 6b. The average last spring frost is May 2 and the first fall frost is October 12, giving you a growing season of approximately 163 days.

At an elevation of 375 feet, Smyth County receives approximately 51.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Cauliflower during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cauliflower root diseases.

Smyth County, VA (Zone 6b) Moderate season
163 days
Last Spring Frost May 2
163 growing days
First Fall Frost October 12

Smyth County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 19 – Aug 21
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 29
Safe Start (90%) ✓ Fits season (41 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jul 14 – Sep 15

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 Smyth County

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

Soil pH

Your soil pH (5.3โ€“6.8) overlaps with Cauliflower's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Smyth County is excellent for Cauliflower โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Cauliflower.

How to Plant Cauliflower

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 Cauliflower

3
successive plantings in your 163-day season

Sow every 6.3 weeks. Last sowing by Jul 04 to harvest before frost.

For a dedicated fall crop, sow by Aug 03.

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

Monthly Watering Guide for Cauliflower

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

Month Cauliflower Needs Rainfall You Supplement Action
Jan โ€” 3.9" 0" โ„๏ธ Dormant
Feb โ€” 3.9" 0" โ„๏ธ Dormant
Mar โ€” 4.6" 0" โ„๏ธ Dormant
Apr โ€” 4.3" 0" โ„๏ธ Dormant
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jul 4.3" 5.4" 0" โœ… Rainfall sufficient
Aug 4.3" 5.7" 0" โœ… Rainfall sufficient
Sep 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Oct 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Nov โ€” 3.7" 0" โ„๏ธ Dormant
Dec โ€” 4.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Smyth County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Cauliflower 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" โ€” every day above 50ยฐF 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.

Cauliflower needs ~1,124 GDD — county provides 2,363 GDD Excellent fit

Cauliflower Planting Timeline โ€” Smyth County, VA

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 2 May 2 โ€“ May 16
Direct Sow April 18 Apr 18 โ€“ May 9
Harvest June 27 Jun 27 โ€“ Aug 29
Fall Sowing August 3 Aug 3 โ€“ Aug 17

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

163 days in Smyth County

Growing Tips for Cauliflower in Smyth County

Direct sow Cauliflower outdoors after May 02 in Smyth County when soil has warmed and frost danger has passed.

Common pests for Cauliflower 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 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

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 Cauliflower in Smyth County, VA?

Smyth County is in Zone 6b with an average last frost of May 2. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Smyth County, VA?

Smyth County, Virginia is in USDA Hardiness Zone 6b. The average last spring frost is May 2 and first fall frost is October 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Smyth County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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