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When to Plant Larkspur in Bastrop County, TX

Larkspur (Consolida ajacis) is a cool-season annual that produces tall, delicate spires of blue, purple, pink, and white flowers reminiscent of its perennial cousin, delphinium. Direct-sown into cold soil or fall-sown in mild-winter climates, it blooms in spring before going to seed as summer heat arrives. An excellent cut flower and cottage-garden staple.

Bastrop 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 3,716 feet, Bastrop County receives approximately 57 inches of rainfall annually with predominantly clay soil. Summer highs average 91°F, providing good warmth for Larkspur during the growing season. Clay soil retains moisture well for Larkspur, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Larkspur root diseases.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Bastrop County, TX (Zone 9a) Year-round
277 days
Last Spring Frost February 27
277 growing days
First Fall Frost December 1

Bastrop County Soil Profile

Soil Type

Clay

Soil pH

7.2-7.9

Drainage

Well Drained

Monthly Watering Guide for Larkspur

Larkspur needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Larkspur Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 4.3" 2.1" 2.2" 🚿 Regular watering
Mar 4.3" 4.1" 0.2" 💧 Light watering
Apr 4.3" 6.1" 0" ✅ Rainfall sufficient
May 4.3" 8.8" 0" ✅ Rainfall sufficient
Jun 4.3" 9.4" 0" ✅ Rainfall sufficient
Jul 4.3" 6.7" 0" ✅ Rainfall sufficient
Aug 4.3" 5.8" 0" ✅ Rainfall sufficient
Sep 4.3" 5.6" 0" ✅ Rainfall sufficient
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 4.3" 1.5" 2.8" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Bastrop County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Larkspur Planting Timeline — Bastrop County, TX

Larkspur Planting Calendar

Activity When Date Range
Bloom December 1 Dec 1 – Mar 23
Fall Sowing September 22 Sep 22 – Oct 6

Plant 0.1" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Bloom
February Bloom
March Bloom
April
May
June
July
August
September Fall Sowing
October Fall Sowing
November
December Bloom

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Bastrop County

Growing Tips for Bastrop County

Larkspur does not transplant well — direct-sow only. In cold climates (zones 2–6), sow directly in early spring as soon as soil can be worked, 4–6 weeks before last frost; cold soil improves germination. In zones 7–10, fall-sow 8–10 weeks before first frost for spring bloom. Press seeds lightly into soil; they need darkness to germinate — cover with 1/8–1/4 inch of soil. Thin to 6–12 inches to prevent powdery mildew. Allow seed pods to mature and self-sow for naturalized colonies. All parts are toxic if ingested.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Larkspur in Bastrop County, TX?

Bastrop County is in Zone 9a with an average last frost of February 27. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bastrop County, TX?

Bastrop County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 27 and first fall frost is December 1.

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Your Bastrop County Garden Planner — Free

A 22-page printable planner built for Bastrop 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 Bastrop County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.