When to Plant Larkspur in Jackson County, OR
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.
Jackson County, Oregon is in USDA Zone 8a. The average last spring frost is May 7 and the first fall frost is October 10, giving you a growing season of approximately 156 days.
At an elevation of 422 feet, Jackson County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Larkspur during the growing season.
Jackson County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.4
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 | — | 6.1" | 0" | ❄️ Dormant |
| Feb | — | 5.8" | 0" | ❄️ Dormant |
| Mar | — | 5.1" | 0" | ❄️ Dormant |
| Apr | — | 3" | 0" | ❄️ Dormant |
| May | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Jun | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Jul | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Aug | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Sep | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Oct | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Nov | — | 6.4" | 0" | ❄️ Dormant |
| Dec | — | 8.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Jackson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Larkspur Planting Timeline — Jackson County, OR
Larkspur Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 9 | Apr 9 – Apr 30 |
| Bloom | June 18 | Jun 18 – Sep 24 |
| Fall Sowing | August 1 | Aug 1 – Aug 15 |
Plant 0.1" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Fall Sowing Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
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 8a
📆 Growing Season
156 days in Jackson County
Growing Tips for Jackson 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 →
Larkspur in Other Locations
Frequently Asked Questions
When should I plant Larkspur in Jackson County, OR?
Jackson County is in Zone 8a with an average last frost of May 7. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.
What planting zone is Jackson County, OR?
Jackson County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is May 7 and first fall frost is October 10.
Your Jackson County Garden Planner — Free
A 22-page printable planner built for Jackson County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.