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When to Plant Microgreens in Smyth County, VA

Smyth County, Virginia Zone 7a May

Smyth County, Virginia gardeners: here's your May plan

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

Avg. last frost May 2
Avg. first frost October 12
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 14 hrs
  1. Time to transplant microgreens

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

  2. Start harvesting microgreens

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

A few tasks this May that'll pay off in June
  • Starting indoors: microgreens
  • First harvests: microgreens

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Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.

Smyth County, Virginia is in USDA Zone 7a. 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 86°F, providing good warmth for Microgreens during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Microgreens root diseases.

Smyth County, VA (Zone 7a) 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 (127 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: May 1 – May 29
Recommended (50%) ✓ Fits season (128 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: May 9 – Jun 6
Safe Start (90%) ✓ Fits season (125 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: May 26 – Jun 23

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 Microgreens's growing requirements.

Soil pH

Your soil pH (5.3–6.8) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Smyth County is excellent for Microgreens — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Succession Planting Microgreens

32
successive plantings in your 163-day season

Sow every 0.7 weeks. Last sowing by Sep 21 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 Microgreens

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

Month Microgreens Needs Rainfall You Supplement Action
Jan 3.9" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 4.3" 0" ❄️ Dormant
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 5.4" 0" ✅ Rainfall sufficient
Aug 4.3" 5.7" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 4.5" 0" ❄️ Dormant

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

Microgreens 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.

Microgreens needs ~203 GDD — county provides 2,363 GDD Excellent fit

Microgreens Planting Timeline — Smyth County, VA

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 18 Apr 18 – May 9
Harvest May 9 May 9 – Jun 6
Fall Sowing August 3 Aug 3 – Aug 17

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

163 days in Smyth County

Growing Tips for Microgreens in Smyth County

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

Your generous 163.0-day season in Smyth County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

General growing tips

Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.

Frequently Asked Questions

When should I plant Microgreens in Smyth County, VA?

Smyth County is in Zone 7a with an average last frost of May 2. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Smyth County, VA?

Smyth County, Virginia is in USDA Hardiness Zone 7a. The average last spring frost is May 2 and first fall frost is October 12.

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Your Smyth County Garden Planner — Free

A 24-page printable planner built for Smyth County (Zone 7a). 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 Smyth County, VA. 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.