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When to Plant Hyssop in Harrison County, MS

Harrison County, Mississippi Zone 9a May

Harrison County, Mississippi gardeners: here's your May plan

Your Harrison County, Mississippi garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 4
Avg. first frost November 26
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting hyssop

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Before June arrives, get these ready
  • First harvests: hyssop

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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.

Harrison County, Mississippi is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 26, giving you a growing season of approximately 267 days.

At an elevation of 190 feet, Harrison County receives approximately 53 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Hyssop may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Hyssop will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Hyssop root diseases.

Harrison County, MS (Zone 9a) Long season
267 days
Last Spring Frost March 4
267 growing days
First Fall Frost November 26
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Harrison County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Transplant: Feb 25 🍅 Harvest: May 6 – Jul 8
Recommended (50%) ✓ Fits season (127 days to spare)
Transplant: Mar 11 🍅 Harvest: May 20 – Jul 22
Safe Start (90%) ✓ Fits season (126 days to spare)
Transplant: Apr 2 🍅 Harvest: Jun 11 – Aug 13

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 Harrison County

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

Soil pH

Your soil pH (4.8–6.2) is more acidic than Hyssop prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Hyssop prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Hyssop.

How to Plant Hyssop

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

Succession Planting Hyssop

4
successive plantings in your 267-day season

Sow every 8 weeks. Last sowing by Aug 28 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 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 4.1" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 2.2" 4.9" 0" ✅ Rainfall sufficient
Apr 2.2" 3.8" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 6.3" 0" ✅ Rainfall sufficient
Aug 2.2" 4.5" 0" ✅ Rainfall sufficient
Sep 2.2" 4.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.6" 0" ✅ Rainfall sufficient
Nov 2.2" 4.3" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Harrison 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 ~1,760 GDD — county provides 5,874 GDD Excellent fit

Hyssop Planting Timeline — Harrison County, MS

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors March 11 Mar 11 – Mar 25
Harvest May 20 May 20 – Jul 22

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

267 days in Harrison County

Growing Tips for Hyssop in Harrison County

Direct sow Hyssop outdoors after March 04 in Harrison County when soil has warmed and frost danger has passed.

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

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 Harrison County, MS?

Harrison County is in Zone 9a with an average last frost of March 4. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harrison County, MS?

Harrison County, Mississippi is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 26.

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Your Harrison County Garden Planner — Free

A 24-page printable planner built for Harrison County (Zone 9a). 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 Harrison County, MS. 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.