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When to Plant Hyssop in Smyth County, VA

Smyth County, Virginia Zone 7a May

Top priorities for Smyth County, Virginia gardeners in May

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. Transplant hyssop outside

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

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Hyssop is a semi-evergreen perennial herb with intense blue flower spikes that attract bees and butterflies. It has a minty, slightly bitter flavor used in liqueurs and teas.

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 Hyssop during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Hyssop 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 (22 days to spare)
Transplant: May 1 🍅 Harvest: Jul 10 – Sep 11
Recommended (50%) ✓ Fits season (23 days to spare)
Transplant: May 9 🍅 Harvest: Jul 18 – Sep 19
Safe Start (90%) ✓ Fits season (20 days to spare)
Transplant: May 26 🍅 Harvest: Aug 4 – Oct 6

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 Hyssop's growing requirements.

Soil pH

Your soil pH (5.3–6.8) overlaps with Hyssop's range (6.0–8.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Hyssop

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Hyssop

2
successive plantings in your 163-day season

Sow every 8 weeks. Last sowing by Jul 14 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Hyssop

Hyssop 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 Hyssop 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 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 5.4" 0" ✅ Rainfall sufficient
Aug 2.2" 5.7" 0" ✅ Rainfall sufficient
Sep 2.2" 3.5" 0" ✅ Rainfall sufficient
Oct 2.2" 3.3" 0" ✅ Rainfall sufficient
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.

Hyssop 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.

Hyssop needs ~1,160 GDD — county provides 2,363 GDD Excellent fit

Hyssop Planting Timeline — Smyth County, VA

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors May 9 May 9 – May 23
Harvest July 18 Jul 18 – Sep 19

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

163 days in Smyth County

Growing Tips for Hyssop in Smyth County

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

General growing tips

Start seeds indoors or direct sow in spring. Prune back in early spring to encourage bushy growth. Hyssop is drought-tolerant once established and thrives in poor soil.

Companion Planting

Good Companions

Avoid Planting Near

  • Radish

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hyssop in Smyth County, VA?

Smyth County is in Zone 7a with an average last frost of May 2. Plan your Hyssop 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.

🌱

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.