When to Plant Arugula in Caldwell County, TX
Your May planting checklist for Caldwell County, Texas
Here's what deserves your attention in Caldwell County, Texas this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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It's harvest week for arugula
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Coming up in June — start thinking about
- First harvests: arugula
Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.
Caldwell County, Texas is in USDA Zone 9a. The average last spring frost is February 27 and the first fall frost is December 1, giving you a growing season of approximately 277 days.
At an elevation of 3,482 feet, Caldwell County receives approximately 60.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Arugula during the growing season. Clay soil retains moisture well for Arugula, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Arugula root diseases.
Caldwell County Soil Profile
Soil Type
Clay
Soil pH
6.8-8.1
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 Caldwell County
How your county's soil matches Arugula's growing requirements.
Soil pH
Your soil pH (6.8–8.1) is more alkaline than Arugula prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Heavy clay soil (43% clay) in Caldwell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (3.3%). Annual compost additions will help Arugula.
How to Plant Arugula
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Arugula
Sow every 3.4 weeks. Last sowing by Oct 12 to harvest before frost.
For a dedicated fall crop, sow by Oct 06.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Arugula
Arugula needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Arugula Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | 2.6" | 2.1" | 0.5" | 💧 Light watering |
| Mar | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| Apr | 2.6" | 6" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 9.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 9.2" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 7.5" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 7.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 5.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 3.8" | 0" | ✅ Rainfall sufficient |
| Nov | 2.6" | 1.8" | 0.8" | 💧 Light watering |
| Dec | 2.6" | 1.5" | 1.1" | 💧 Light watering |
Water needs are for active growing months only (Feb–Dec in Caldwell County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Arugula 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.
Arugula Planting Timeline — Caldwell County, TX
Arugula Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 30 | Jan 30 – Feb 13 |
| Transplant Outdoors | February 27 | Feb 27 – Mar 13 |
| Direct Sow | February 6 | Feb 6 – Feb 27 |
| Harvest | April 3 | Apr 3 – Jun 5 |
| Fall Sowing | October 6 | Oct 6 – Oct 20 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
30–50 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9a
📆 Growing Season
277 days in Caldwell County
Growing Tips for Arugula in Caldwell County
Direct sow Arugula outdoors after February 27 in Caldwell County when soil has warmed and frost danger has passed.
With Caldwell County's clay soil (43% clay), work in 3-4 inches of compost before planting Arugula. Avoid tilling when soil is wet to prevent compaction.
Your generous 278.0-day season in Caldwell County allows multiple plantings of Arugula. Sow every 15.0 days for continuous harvest.
Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Arugula in Other Locations
Frequently Asked Questions
When should I plant Arugula in Caldwell County, TX?
Caldwell County is in Zone 9a with an average last frost of February 27. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.
What planting zone is Caldwell County, TX?
Caldwell County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 27 and first fall frost is December 1.
Your Caldwell County Garden Planner — Free
A 24-page printable planner built for Caldwell 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.