When to Plant Hyssop in Randall County, TX
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.
Randall County, Texas is in USDA Zone 7a. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.
At an elevation of 1,230 feet, Randall County receives approximately 57.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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.
Randall County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.7-8.3
Drainage
Well Drained
Plant Planting Risk Windows
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 Randall County
How your county's soil matches Hyssop's growing requirements.
Soil pH
Your soil pH (7.7–8.3) overlaps with Hyssop's range (6.0–8.0), though not a perfect match.
Soil Texture
Sandy soil in Randall County warms quickly in spring but drains fast. Hyssop will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Hyssop.
Organic Matter
Organic matter is low (1.1%). Add 2-3 inches of compost before planting Hyssop.
How to Plant Hyssop
Succession Planting Hyssop
Sow every 8 weeks. Last sowing by Jul 26 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 3.3" | 0" | ❄️ Dormant |
| Mar | — | 3.2" | 0" | ❄️ Dormant |
| Apr | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| May | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jun | 2.2" | 2" | 0.2" | 💧 Light watering |
| Jul | 2.2" | 8.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 11.2" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 7.7" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 5.6" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.3" | 0" | ❄️ Dormant |
| Dec | — | 4.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Randall 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 Planting Timeline — Randall County, TX
Hyssop Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 22 | Apr 22 – May 6 |
| Harvest | July 1 | Jul 1 – Sep 2 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| 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
192 days in Randall County
Growing Tips for Hyssop in Randall County
Direct sow Hyssop outdoors after April 15 in Randall County when soil has warmed and frost danger has passed.
Sandy soil in Randall County dries quickly — mulch Hyssop with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
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
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Check more plant combinations with our Companion Planting Checker →
Hyssop in Other Locations
Frequently Asked Questions
When should I plant Hyssop in Randall County, TX?
Randall County is in Zone 7a with an average last frost of April 15. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.
What planting zone is Randall County, TX?
Randall County, Texas is in USDA Hardiness Zone 7a. The average last spring frost is April 15 and first fall frost is October 24.
Plan Your Garden with Confidence
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