Blog

When to Plant Hyssop in Mills County, TX

Mills County, Texas Zone 8b May

Your May gardening checklist

Your garden in Mills County, Texas is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 23
Avg. first frost November 12
Soil temp (4") 63°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
To set up a strong June, finish these tasks
  • First harvests: hyssop

Instant PDF download. No spam, unsubscribe any time.

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.

Mills County, Texas is in USDA Zone 8b. The average last spring frost is March 23 and the first fall frost is November 12, giving you a growing season of approximately 234 days.

At an elevation of 4,208 feet, Mills County receives approximately 61.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°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.

Mills County, TX (Zone 8b) Long season
234 days
Last Spring Frost March 23
234 growing days
First Fall Frost November 12
Share this guide:

Mills County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (97 days to spare)
Transplant: Mar 19 🍅 Harvest: May 28 – Jul 30
Recommended (50%) ✓ Fits season (94 days to spare)
Transplant: Mar 30 🍅 Harvest: Jun 8 – Aug 10
Safe Start (90%) ✓ Fits season (91 days to spare)
Transplant: Apr 21 🍅 Harvest: Jun 30 – Sep 1

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 Mills County

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

Soil pH

Your soil pH (6.7–7.6) is within Hyssop's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Hyssop.

How to Plant Hyssop

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

Succession Planting Hyssop

3
successive plantings in your 234-day season

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

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/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 1.7" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 2.2" 3.8" 0" ✅ Rainfall sufficient
Apr 2.2" 6.2" 0" ✅ Rainfall sufficient
May 2.2" 10.5" 0" ✅ Rainfall sufficient
Jun 2.2" 9.5" 0" ✅ Rainfall sufficient
Jul 2.2" 7.5" 0" ✅ Rainfall sufficient
Aug 2.2" 7" 0" ✅ Rainfall sufficient
Sep 2.2" 5.6" 0" ✅ Rainfall sufficient
Oct 2.2" 4.2" 0" ✅ Rainfall sufficient
Nov 2.2" 2" 0.2" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Mills 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 ~1,400 GDD — county provides 4,095 GDD Excellent fit

Hyssop Planting Timeline — Mills County, TX

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors March 30 Mar 30 – Apr 13
Harvest June 8 Jun 8 – Aug 10

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

Month-by-Month Timeline

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

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: ideal

🗺️ USDA Zone

Zone 8b

📆 Growing Season

234 days in Mills County

Growing Tips for Hyssop in Mills County

Direct sow Hyssop outdoors after March 23 in Mills 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 Mills County, TX?

Mills County is in Zone 8b with an average last frost of March 23. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mills County, TX?

Mills County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 23 and first fall frost is November 12.

🌱

Your Mills County Garden Planner — Free

A 24-page printable planner built for Mills County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Mills 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.